/*
** This is the amalgamated source code to the "sqlite3" or "sqlite3.exe"
** command-line shell (CLI) for SQLite.  This file is automatically
** generated by the tool/mkshellc.tcl script from the following sources:
**
**   ext/expert/sqlite3expert.c
**   ext/expert/sqlite3expert.h
**   ext/intck/sqlite3intck.c
**   ext/intck/sqlite3intck.h
**   ext/misc/appendvfs.c
**   ext/misc/base64.c
**   ext/misc/base85.c
**   ext/misc/completion.c
**   ext/misc/decimal.c
**   ext/misc/fileio.c
**   ext/misc/ieee754.c
**   ext/misc/memtrace.c
**   ext/misc/pcachetrace.c
**   ext/misc/regexp.c
**   ext/misc/series.c
**   ext/misc/sha1.c
**   ext/misc/shathree.c
**   ext/misc/sqlar.c
**   ext/misc/sqlite3_stdio.c
**   ext/misc/sqlite3_stdio.h
**   ext/misc/stmtrand.c
**   ext/misc/uint.c
**   ext/misc/vfstrace.c
**   ext/misc/windirent.h
**   ext/misc/zipfile.c
**   ext/qrf/qrf.c
**   ext/qrf/qrf.h
**   ext/recover/dbdata.c
**   ext/recover/sqlite3recover.c
**   ext/recover/sqlite3recover.h
**   src/shell.c.in
**
** To modify this program, get a copy of the canonical SQLite source tree,
** edit the src/shell.c.in file and/or some of the other files that are
** listed above, then rerun the command "make shell.c".
*/
/************************* Begin src/shell.c.in ******************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement the "sqlite3" command line
** utility for accessing SQLite databases.
*/
#if (defined(_WIN32) || defined(WIN32)) && !defined(_CRT_SECURE_NO_WARNINGS)
/* This needs to come before any includes for MSVC compiler */
#define _CRT_SECURE_NO_WARNINGS
#endif
typedef unsigned int u32;
typedef unsigned short int u16;

/*
** Limit input nesting via .read or any other input redirect.
** It's not too expensive, so a generous allowance can be made.
*/
#define MAX_INPUT_NESTING 25

/*
** Used to prevent warnings about unused parameters
*/
#define UNUSED_PARAMETER(x) (void)(x)

/*
** Number of elements in an array
*/
#define ArraySize(X)  (int)(sizeof(X)/sizeof(X[0]))

/*
** Optionally #include a user-defined header, whereby compilation options
** may be set prior to where they take effect, but after platform setup.
** If SQLITE_CUSTOM_INCLUDE=? is defined, its value names the #include
** file. Note that this macro has a like effect on sqlite3.c compilation.
*/
# define SHELL_STRINGIFY_(f) #f
# define SHELL_STRINGIFY(f) SHELL_STRINGIFY_(f)
#ifdef SQLITE_CUSTOM_INCLUDE
# include SHELL_STRINGIFY(SQLITE_CUSTOM_INCLUDE)
#endif

/*
** If SQLITE_SHELL_FIDDLE is defined then the shell is modified
** somewhat for use as a WASM module in a web browser. This flag
** should only be used when building the "fiddle" web application, as
** the browser-mode build has much different user input requirements
** and this build mode rewires the user input subsystem to account for
** that.
*/
#if defined(SQLITE_SHELL_FIDDLE)
# undef SQLITE_OMIT_LOAD_EXTENSION
# define SQLITE_OMIT_LOAD_EXTENSION 1
#endif

/*
** Warning pragmas copied from msvc.h in the core.
*/
#if defined(_MSC_VER)
#pragma warning(disable : 4054)
#pragma warning(disable : 4055)
#pragma warning(disable : 4100)
#pragma warning(disable : 4127)
#pragma warning(disable : 4130)
#pragma warning(disable : 4152)
#pragma warning(disable : 4189)
#pragma warning(disable : 4206)
#pragma warning(disable : 4210)
#pragma warning(disable : 4232)
#pragma warning(disable : 4244)
#pragma warning(disable : 4305)
#pragma warning(disable : 4306)
#pragma warning(disable : 4702)
#pragma warning(disable : 4706)
#endif /* defined(_MSC_VER) */

/*
** No support for loadable extensions in VxWorks.
*/
#if (defined(__RTP__) || defined(_WRS_KERNEL)) && !SQLITE_OMIT_LOAD_EXTENSION
# define SQLITE_OMIT_LOAD_EXTENSION 1
#endif

/*
** Enable large-file support for fopen() and friends on unix.
*/
#ifndef SQLITE_DISABLE_LFS
# define _LARGE_FILE       1
# ifndef _FILE_OFFSET_BITS
#   define _FILE_OFFSET_BITS 64
# endif
# define _LARGEFILE_SOURCE 1
#endif

#if defined(SQLITE_SHELL_FIDDLE) && !defined(_POSIX_SOURCE)
/*
** emcc requires _POSIX_SOURCE (or one of several similar defines)
** to expose strdup().
*/
# define _POSIX_SOURCE
#endif

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <stdint.h>
#include "sqlite3.h"
typedef sqlite3_int64 i64;
typedef sqlite3_uint64 u64;
typedef unsigned char u8;
#include <ctype.h>
#include <stdarg.h>
#ifndef _WIN32
# include <sys/time.h>
# include <sys/ioctl.h>
#endif

#if !defined(_WIN32) && !defined(WIN32)
# include <signal.h>
# if !defined(__RTP__) && !defined(_WRS_KERNEL) && !defined(SQLITE_WASI)
#  include <pwd.h>
# endif
#endif
#if (!defined(_WIN32) && !defined(WIN32)) || defined(__MINGW32__)
# include <unistd.h>
# include <dirent.h>
# define GETPID getpid
# if defined(__MINGW32__)
#  define DIRENT dirent
#  ifndef S_ISLNK
#   define S_ISLNK(mode) (0)
#  endif
# endif
#else
# define GETPID (int)GetCurrentProcessId
#endif
#include <sys/types.h>
#include <sys/stat.h>

#if HAVE_READLINE
# include <readline/readline.h>
# include <readline/history.h>
#endif

#if HAVE_EDITLINE
# include <editline/readline.h>
#endif

#if HAVE_EDITLINE || HAVE_READLINE

# define shell_add_history(X) add_history(X)
# define shell_read_history(X) read_history(X)
# define shell_write_history(X) write_history(X)
# define shell_stifle_history(X) stifle_history(X)
# define shell_readline(X) readline(X)

#elif HAVE_LINENOISE

# include "linenoise.h"
# define shell_add_history(X) linenoiseHistoryAdd(X)
# define shell_read_history(X) linenoiseHistoryLoad(X)
# define shell_write_history(X) linenoiseHistorySave(X)
# define shell_stifle_history(X) linenoiseHistorySetMaxLen(X)
# define shell_readline(X) linenoise(X)

#else

# define shell_read_history(X)
# define shell_write_history(X)
# define shell_stifle_history(X)

# define SHELL_USE_LOCAL_GETLINE 1
#endif

#ifndef deliberate_fall_through
/* Quiet some compilers about some of our intentional code. */
# if defined(GCC_VERSION) && GCC_VERSION>=7000000
#  define deliberate_fall_through __attribute__((fallthrough));
# else
#  define deliberate_fall_through
# endif
#endif

#if defined(_WIN32) || defined(WIN32)
#  include <io.h>
#  include <fcntl.h>
#  define isatty(h) _isatty(h)
#  ifndef access
#   define access(f,m) _access((f),(m))
#  endif
#  ifndef unlink
#   define unlink _unlink
#  endif
#  ifndef strdup
#   define strdup _strdup
#  endif
#  undef pclose
#  define pclose _pclose
#else
 /* Make sure isatty() has a prototype. */
 extern int isatty(int);

# if !defined(__RTP__) && !defined(_WRS_KERNEL) && !defined(SQLITE_WASI)
  /* popen and pclose are not C89 functions and so are
  ** sometimes omitted from the <stdio.h> header */
   extern FILE *popen(const char*,const char*);
   extern int pclose(FILE*);
# else
#  define SQLITE_OMIT_POPEN 1
# endif
#endif

#if defined(_WIN32_WCE)
/* Windows CE (arm-wince-mingw32ce-gcc) does not provide isatty()
 * thus we always assume that we have a console. That can be
 * overridden with the -batch command line option.
 */
#define isatty(x) 1
#endif

/* ctype macros that work with signed characters */
#define IsSpace(X)  isspace((unsigned char)X)
#define IsDigit(X)  isdigit((unsigned char)X)
#define ToLower(X)  (char)tolower((unsigned char)X)
#define IsAlnum(X)  isalnum((unsigned char)X)
#define IsAlpha(X)  isalpha((unsigned char)X)

#if defined(_WIN32) || defined(WIN32)
#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* string conversion routines only needed on Win32 */
extern char *sqlite3_win32_unicode_to_utf8(LPCWSTR);
extern LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText);
#endif

/************************* Begin ext/misc/sqlite3_stdio.h ******************/
/*
** 2024-09-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This header file contains definitions of interfaces that provide 
** cross-platform I/O for UTF-8 content.
**
** On most platforms, the interfaces definitions in this file are
** just #defines.  For example sqlite3_fopen() is a macro that resolves
** to the standard fopen() in the C-library.
**
** But Windows does not have a standard C-library, at least not one that
** can handle UTF-8.  So for windows build, the interfaces resolve to new
** C-language routines contained in the separate sqlite3_stdio.c source file.
**
** So on all non-Windows platforms, simply #include this header file and
** use the interfaces defined herein.  Then to run your application on Windows,
** also link in the accompanying sqlite3_stdio.c source file when compiling
** to get compatible interfaces.
*/
#ifndef _SQLITE3_STDIO_H_
#define _SQLITE3_STDIO_H_ 1
#ifdef _WIN32
/**** Definitions For Windows ****/
#include <stdio.h>
#include <stdarg.h>
#include <windows.h>

FILE *sqlite3_fopen(const char *zFilename, const char *zMode);
FILE *sqlite3_popen(const char *zCommand, const char *type);
char *sqlite3_fgets(char *s, int size, FILE *stream);
int sqlite3_fputs(const char *s, FILE *stream);
int sqlite3_fprintf(FILE *stream, const char *format, ...);
int sqlite3_vfprintf(FILE *stream, const char *format, va_list);
void sqlite3_fsetmode(FILE *stream, int mode);


#else
/**** Definitions For All Other Platforms ****/
#include <stdio.h>
#define sqlite3_fopen     fopen
#define sqlite3_popen     popen
#define sqlite3_fgets     fgets
#define sqlite3_fputs     fputs
#define sqlite3_fprintf   fprintf
#define sqlite3_vfprintf  vfprintf
#define sqlite3_fsetmode(F,X)   /*no-op*/

#endif
#endif /* _SQLITE3_STDIO_H_ */

/************************* End ext/misc/sqlite3_stdio.h ********************/
/************************* Begin ext/misc/sqlite3_stdio.c ******************/
/*
** 2024-09-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Implementation of standard I/O interfaces for UTF-8 that are missing
** on Windows.
*/
#ifdef _WIN32  /* This file is a no-op on all platforms except Windows */
#ifndef _SQLITE3_STDIO_H_
/* #include "sqlite3_stdio.h" */
#endif
#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
/* #include "sqlite3.h" */
#include <ctype.h>
#include <stdarg.h>
#include <io.h>
#include <fcntl.h>

/*
** If the SQLITE_U8TEXT_ONLY option is defined, then use O_U8TEXT
** when appropriate on all output.  (Sometimes use O_BINARY when
** rendering ASCII text in cases where NL-to-CRLF expansion would
** not be correct.)
**
** If the SQLITE_U8TEXT_STDIO option is defined, then use O_U8TEXT
** when appropriate when writing to stdout or stderr.  Use O_BINARY
** or O_TEXT (depending on things like the .mode and the .crlf setting
** in the CLI, or other context clues in other applications) for all
** other output channels.
**
** The default behavior, if neither of the above is defined is to
** use O_U8TEXT when writing to the Windows console (or anything
** else for which _isatty() returns true) and to use O_BINARY or O_TEXT
** for all other output channels.
**
** The SQLITE_USE_W32_FOR_CONSOLE_IO macro is also available.  If
** defined, it forces the use of Win32 APIs for all console I/O, both
** input and output.  This is necessary for some non-Microsoft run-times
** that implement stdio differently from Microsoft/Visual-Studio.
*/
#if defined(SQLITE_U8TEXT_ONLY)
# define UseWtextForOutput(fd) 1
# define UseWtextForInput(fd)  1
# define IsConsole(fd)         _isatty(_fileno(fd))
#elif defined(SQLITE_U8TEXT_STDIO)
# define UseWtextForOutput(fd) ((fd)==stdout || (fd)==stderr)
# define UseWtextForInput(fd)  ((fd)==stdin)
# define IsConsole(fd)         _isatty(_fileno(fd))
#else
# define UseWtextForOutput(fd) _isatty(_fileno(fd))
# define UseWtextForInput(fd)  _isatty(_fileno(fd))
# define IsConsole(fd)         1
#endif

/*
** Global variables determine if simulated O_BINARY mode is to be
** used for stdout or other, respectively.  Simulated O_BINARY mode
** means the mode is usually O_BINARY, but switches to O_U8TEXT for
** unicode characters U+0080 or greater (any character that has a
** multi-byte representation in UTF-8).  This is the only way we
** have found to render Unicode characters on a Windows console while
** at the same time avoiding undesirable \n to \r\n translation.
*/
static int simBinaryStdout = 0;
static int simBinaryOther = 0;


/*
** Determine if simulated binary mode should be used for output to fd
*/
static int UseBinaryWText(FILE *fd){
  if( fd==stdout || fd==stderr ){
    return simBinaryStdout;
  }else{
    return simBinaryOther;
  }
}


/*
** Work-alike for the fopen() routine from the standard C library.
*/
FILE *sqlite3_fopen(const char *zFilename, const char *zMode){
  FILE *fp = 0;
  wchar_t *b1, *b2;
  int sz1, sz2;

  sz1 = (int)strlen(zFilename);
  sz2 = (int)strlen(zMode);
  b1 = sqlite3_malloc64( (sz1+1)*sizeof(b1[0]) );
  b2 = sqlite3_malloc64( (sz2+1)*sizeof(b1[0]) );
  if( b1 && b2 ){
    sz1 = MultiByteToWideChar(CP_UTF8, 0, zFilename, sz1, b1, sz1);
    b1[sz1] = 0;
    sz2 = MultiByteToWideChar(CP_UTF8, 0, zMode, sz2, b2, sz2);
    b2[sz2] = 0;
    fp = _wfopen(b1, b2);
  }
  sqlite3_free(b1);
  sqlite3_free(b2);
  simBinaryOther = 0;
  return fp;
}


/*
** Work-alike for the popen() routine from the standard C library.
*/
FILE *sqlite3_popen(const char *zCommand, const char *zMode){
  FILE *fp = 0;
  wchar_t *b1, *b2;
  int sz1, sz2;

  sz1 = (int)strlen(zCommand);
  sz2 = (int)strlen(zMode);
  b1 = sqlite3_malloc64( (sz1+1)*sizeof(b1[0]) );
  b2 = sqlite3_malloc64( (sz2+1)*sizeof(b1[0]) );
  if( b1 && b2 ){
    sz1 = MultiByteToWideChar(CP_UTF8, 0, zCommand, sz1, b1, sz1);
    b1[sz1] = 0;
    sz2 = MultiByteToWideChar(CP_UTF8, 0, zMode, sz2, b2, sz2);
    b2[sz2] = 0;
    fp = _wpopen(b1, b2);
  }
  sqlite3_free(b1);
  sqlite3_free(b2);
  return fp;
}

/*
** Work-alike for fgets() from the standard C library.
*/
char *sqlite3_fgets(char *buf, int sz, FILE *in){
  if( UseWtextForInput(in) ){
    /* When reading from the command-prompt in Windows, it is necessary
    ** to use _O_WTEXT input mode to read UTF-16 characters, then translate
    ** that into UTF-8.  Otherwise, non-ASCII characters all get translated
    ** into '?'.
    */
    wchar_t *b1 = sqlite3_malloc64( sz*sizeof(wchar_t) );
    if( b1==0 ) return 0;
#ifdef SQLITE_USE_W32_FOR_CONSOLE_IO
    DWORD nRead = 0;
    if( IsConsole(in)
     && ReadConsoleW(GetStdHandle(STD_INPUT_HANDLE), b1, sz-1, &nRead, 0)
    ){
      b1[nRead] = 0;
    }else
#endif
    {
      _setmode(_fileno(in), IsConsole(in) ? _O_WTEXT : _O_U8TEXT);
      if( fgetws(b1, sz/4, in)==0 ){
        sqlite3_free(b1);
        return 0;
      }
    }
    WideCharToMultiByte(CP_UTF8, 0, b1, -1, buf, sz, 0, 0);
    sqlite3_free(b1);
    return buf;
  }else{
    /* Reading from a file or other input source, just read bytes without
    ** any translation. */
    return fgets(buf, sz, in);
  }
}

/*
** Send ASCII text as O_BINARY.  But for Unicode characters U+0080 and
** greater, switch to O_U8TEXT.
*/
static void piecemealOutput(wchar_t *b1, int sz, FILE *out){
  int i;
  wchar_t c;
  while( sz>0 ){
    for(i=0; i<sz && b1[i]>=0x80; i++){}
    if( i>0 ){
      c = b1[i];
      b1[i] = 0;
      fflush(out);
      _setmode(_fileno(out), _O_U8TEXT);
      fputws(b1, out);
      fflush(out);
      b1 += i;
      b1[0] = c;
      sz -= i;
    }else{
      fflush(out);
      _setmode(_fileno(out), _O_TEXT);
      _setmode(_fileno(out), _O_BINARY);
      fwrite(&b1[0], 1, 1, out);
      for(i=1; i<sz && b1[i]<0x80; i++){
        fwrite(&b1[i], 1, 1, out);
      }
      fflush(out);
      _setmode(_fileno(out), _O_U8TEXT);
      b1 += i;
      sz -= i;
    }
  }
}

/*
** Work-alike for fputs() from the standard C library.
*/
int sqlite3_fputs(const char *z, FILE *out){
  if( !UseWtextForOutput(out) ){
    /* Writing to a file or other destination, just write bytes without
    ** any translation. */
    return fputs(z, out);
  }else{
    /* One must use UTF16 in order to get unicode support when writing
    ** to the console on Windows. 
    */
    int sz = (int)strlen(z);
    wchar_t *b1 = sqlite3_malloc64( (sz+1)*sizeof(wchar_t) );
    if( b1==0 ) return 0;
    sz = MultiByteToWideChar(CP_UTF8, 0, z, sz, b1, sz);
    b1[sz] = 0;

#ifdef SQLITE_USE_W32_FOR_CONSOLE_IO
    DWORD nWr = 0;
    if( IsConsole(out)
      && WriteConsoleW(GetStdHandle(STD_OUTPUT_HANDLE),b1,sz,&nWr,0)
    ){
      /* If writing to the console, then the WriteConsoleW() is all we
      ** need to do. */
    }else
#endif
    {
      /* As long as SQLITE_USE_W32_FOR_CONSOLE_IO is not defined, or for
      ** non-console I/O even if that macro is defined, write using the
      ** standard library. */
      _setmode(_fileno(out), _O_U8TEXT);
      if( UseBinaryWText(out) ){
        piecemealOutput(b1, sz, out);
      }else{
        fputws(b1, out);
      }
    }
    sqlite3_free(b1);
    return 0;
  }
}


/*
** Work-alikes for fprintf() and vfprintf() from the standard C library.
*/
int sqlite3_fprintf(FILE *out, const char *zFormat, ...){
  int rc;
  if( UseWtextForOutput(out) ){
    /* When writing to the command-prompt in Windows, it is necessary
    ** to use _O_WTEXT input mode and write UTF-16 characters.
    */
    char *z;
    va_list ap;

    va_start(ap, zFormat);
    z = sqlite3_vmprintf(zFormat, ap);
    va_end(ap);
    sqlite3_fputs(z, out);
    rc = (int)strlen(z);
    sqlite3_free(z);
  }else{
    /* Writing to a file or other destination, just write bytes without
    ** any translation. */
    va_list ap;
    va_start(ap, zFormat);
    rc = vfprintf(out, zFormat, ap);
    va_end(ap);
  }
  return rc;
}
int sqlite3_vfprintf(FILE *out, const char *zFormat, va_list ap){
  int rc;
  if( UseWtextForOutput(out) ){
    /* When writing to the command-prompt in Windows, it is necessary
    ** to use _O_WTEXT input mode and write UTF-16 characters.
    */
    char *z;
    z = sqlite3_vmprintf(zFormat, ap);
    sqlite3_fputs(z, out);
    rc = (int)strlen(z);
    sqlite3_free(z);
  }else{
    /* Writing to a file or other destination, just write bytes without
    ** any translation. */
    rc = vfprintf(out, zFormat, ap);
  }
  return rc;
}

/*
** Set the mode for an output stream.  mode argument is typically _O_BINARY or
** _O_TEXT.
*/
void sqlite3_fsetmode(FILE *fp, int mode){
  if( !UseWtextForOutput(fp) ){
    fflush(fp);
    _setmode(_fileno(fp), mode);
  }else if( fp==stdout || fp==stderr ){
    simBinaryStdout = (mode==_O_BINARY);
  }else{
    simBinaryOther = (mode==_O_BINARY);
  }
}

#endif /* defined(_WIN32) */

/************************* End ext/misc/sqlite3_stdio.c ********************/
/************************* Begin ext/qrf/qrf.h ******************/
/*
** 2025-10-20
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Header file for the Query Result-Format or "qrf" utility library for
** SQLite.  See the README.md documentation for additional information.
*/
#ifndef SQLITE_QRF_H
#define SQLITE_QRF_H
#ifdef __cplusplus
extern "C" {
#endif
#include <stdlib.h>
/* #include "sqlite3.h" */

/*
** Specification used by clients to define the output format they want
*/
typedef struct sqlite3_qrf_spec sqlite3_qrf_spec;
struct sqlite3_qrf_spec {
  unsigned char iVersion;     /* Version number of this structure */
  unsigned char eStyle;       /* Formatting style.  "box", "csv", etc... */
  unsigned char eEsc;         /* How to escape control characters in text */
  unsigned char eText;        /* Quoting style for text */
  unsigned char eTitle;       /* Quating style for the text of column names */
  unsigned char eBlob;        /* Quoting style for BLOBs */
  unsigned char bTitles;      /* True to show column names */
  unsigned char bWordWrap;    /* Try to wrap on word boundaries */
  unsigned char bTextJsonb;   /* Render JSONB blobs as JSON text */
  unsigned char eDfltAlign;   /* Default alignment, no covered by aAlignment */
  unsigned char eTitleAlign;  /* Alignment for column headers */
  unsigned char bSplitColumn; /* Wrap single-column output into many columns */
  unsigned char bBorder;      /* Show outer border in Box and Table styles */
  short int nWrap;            /* Wrap columns wider than this */
  short int nScreenWidth;     /* Maximum overall table width */
  short int nLineLimit;       /* Maximum number of lines for any row */
  short int nTitleLimit;      /* Maximum number of characters in a title */
  unsigned int nMultiInsert;  /* Add rows to one INSERT until size exceeds */
  int nCharLimit;             /* Maximum number of characters in a cell */
  int nWidth;                 /* Number of entries in aWidth[] */
  int nAlign;                 /* Number of entries in aAlignment[] */
  short int *aWidth;          /* Column widths */
  unsigned char *aAlign;      /* Column alignments */
  char *zColumnSep;           /* Alternative column separator */
  char *zRowSep;              /* Alternative row separator */
  char *zTableName;           /* Output table name */
  char *zNull;                /* Rendering of NULL */
  char *(*xRender)(void*,sqlite3_value*);           /* Render a value */
  int (*xWrite)(void*,const char*,sqlite3_int64);   /* Write output */
  void *pRenderArg;           /* First argument to the xRender callback */
  void *pWriteArg;            /* First argument to the xWrite callback */
  char **pzOutput;            /* Storage location for output string */
  /* Additional fields may be added in the future */
};

/*
** Interfaces
*/
int sqlite3_format_query_result(
  sqlite3_stmt *pStmt,             /* SQL statement to run */
  const sqlite3_qrf_spec *pSpec,   /* Result format specification */
  char **pzErr                     /* OUT: Write error message here */
);

/*
** Range of values for sqlite3_qrf_spec.aWidth[] entries and for
** sqlite3_qrf_spec.mxColWidth and .nScreenWidth
*/
#define QRF_MAX_WIDTH    10000
#define QRF_MIN_WIDTH    0

/*
** Output styles:
*/
#define QRF_STYLE_Auto      0 /* Choose a style automatically */
#define QRF_STYLE_Box       1 /* Unicode box-drawing characters */
#define QRF_STYLE_Column    2 /* One record per line in neat columns */
#define QRF_STYLE_Count     3 /* Output only a count of the rows of output */
#define QRF_STYLE_Csv       4 /* Comma-separated-value */
#define QRF_STYLE_Eqp       5 /* Format EXPLAIN QUERY PLAN output */
#define QRF_STYLE_Explain   6 /* EXPLAIN output */
#define QRF_STYLE_Html      7 /* Generate an XHTML table */
#define QRF_STYLE_Insert    8 /* Generate SQL "insert" statements */
#define QRF_STYLE_Json      9 /* Output is a list of JSON objects */
#define QRF_STYLE_JObject  10 /* Independent JSON objects for each row */
#define QRF_STYLE_Line     11 /* One column per line. */
#define QRF_STYLE_List     12 /* One record per line with a separator */
#define QRF_STYLE_Markdown 13 /* Markdown formatting */
#define QRF_STYLE_Off      14 /* No query output shown */
#define QRF_STYLE_Quote    15 /* SQL-quoted, comma-separated */
#define QRF_STYLE_Stats    16 /* EQP-like output but with performance stats */
#define QRF_STYLE_StatsEst 17 /* EQP-like output with planner estimates */
#define QRF_STYLE_StatsVm  18 /* EXPLAIN-like output with performance stats */
#define QRF_STYLE_Table    19 /* MySQL-style table formatting */

/*
** Quoting styles for text.
** Allowed values for sqlite3_qrf_spec.eText
*/
#define QRF_TEXT_Auto    0 /* Choose text encoding automatically */
#define QRF_TEXT_Plain   1 /* Literal text */
#define QRF_TEXT_Sql     2 /* Quote as an SQL literal */
#define QRF_TEXT_Csv     3 /* CSV-style quoting */
#define QRF_TEXT_Html    4 /* HTML-style quoting */
#define QRF_TEXT_Tcl     5 /* C/Tcl quoting */
#define QRF_TEXT_Json    6 /* JSON quoting */
#define QRF_TEXT_Relaxed 7 /* Relaxed SQL quoting */

/*
** Quoting styles for BLOBs
** Allowed values for sqlite3_qrf_spec.eBlob
*/
#define QRF_BLOB_Auto    0 /* Determine BLOB quoting using eText */
#define QRF_BLOB_Text    1 /* Display content exactly as it is */
#define QRF_BLOB_Sql     2 /* Quote as an SQL literal */
#define QRF_BLOB_Hex     3 /* Hexadecimal representation */
#define QRF_BLOB_Tcl     4 /* "\000" notation */
#define QRF_BLOB_Json    5 /* A JSON string */
#define QRF_BLOB_Size    6 /* Display the blob size only */

/*
** Control-character escape modes.
** Allowed values for sqlite3_qrf_spec.eEsc
*/
#define QRF_ESC_Auto    0 /* Choose the ctrl-char escape automatically */
#define QRF_ESC_Off     1 /* Do not escape control characters */
#define QRF_ESC_Ascii   2 /* Unix-style escapes.  Ex: U+0007 shows ^G */
#define QRF_ESC_Symbol  3 /* Unicode escapes. Ex: U+0007 shows U+2407 */

/*
** Allowed values for "boolean" fields, such as "bColumnNames", "bWordWrap",
** and "bTextJsonb".  There is an extra "auto" variants so these are actually
** tri-state settings, not booleans.
*/
#define QRF_SW_Auto     0 /* Let QRF choose the best value */
#define QRF_SW_Off      1 /* This setting is forced off */
#define QRF_SW_On       2 /* This setting is forced on */
#define QRF_Auto        0 /* Alternate spelling for QRF_*_Auto */
#define QRF_No          1 /* Alternate spelling for QRF_SW_Off */
#define QRF_Yes         2 /* Alternate spelling for QRF_SW_On */

/*
** Possible alignment values alignment settings
**
**                             Horizontal   Vertial
**                             ----------   --------  */
#define QRF_ALIGN_Auto    0 /*   auto        auto     */
#define QRF_ALIGN_Left    1 /*   left        auto     */
#define QRF_ALIGN_Center  2 /*   center      auto     */
#define QRF_ALIGN_Right   3 /*   right       auto     */
#define QRF_ALIGN_Top     4 /*   auto        top      */
#define QRF_ALIGN_NW      5 /*   left        top      */
#define QRF_ALIGN_N       6 /*   center      top      */
#define QRF_ALIGN_NE      7 /*   right       top      */
#define QRF_ALIGN_Middle  8 /*   auto        middle   */
#define QRF_ALIGN_W       9 /*   left        middle   */
#define QRF_ALIGN_C      10 /*   center      middle   */
#define QRF_ALIGN_E      11 /*   right       middle   */
#define QRF_ALIGN_Bottom 12 /*   auto        bottom   */
#define QRF_ALIGN_SW     13 /*   left        bottom   */
#define QRF_ALIGN_S      14 /*   center      bottom   */
#define QRF_ALIGN_SE     15 /*   right       bottom   */
#define QRF_ALIGN_HMASK   3 /* Horizontal alignment mask */
#define QRF_ALIGN_VMASK  12 /* Vertical alignment mask */

/*
** Auxiliary routines contined within this module that might be useful
** in other contexts, and which are therefore exported.
*/
/*
** Return an estimate of the width, in columns, for the single Unicode
** character c.  For normal characters, the answer is always 1.  But the
** estimate might be 0 or 2 for zero-width and double-width characters.
**
** Different devices display unicode using different widths.  So
** it is impossible to know that true display width with 100% accuracy.
** Inaccuracies in the width estimates might cause columns to be misaligned.
** Unfortunately, there is nothing we can do about that.
*/
int sqlite3_qrf_wcwidth(int c);

/*
** Return an estimate of the number of display columns used by the
** string in the argument.  The width of individual characters is
** determined as for sqlite3_qrf_wcwidth().  VT100 escape code sequences
** are assigned a width of zero.
*/
size_t sqlite3_qrf_wcswidth(const char*);


#ifdef __cplusplus
}
#endif
#endif /* !defined(SQLITE_QRF_H) */

/************************* End ext/qrf/qrf.h ********************/
/************************* Begin ext/qrf/qrf.c ******************/
/*
** 2025-10-20
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Implementation of the Query Result-Format or "qrf" utility library for
** SQLite.  See the README.md documentation for additional information.
*/
#ifndef SQLITE_QRF_H
#include "qrf.h"
#endif
#include <string.h>
#include <assert.h>
#include <stdint.h>

#ifndef SQLITE_AMALGAMATION
/* typedef sqlite3_int64 i64; */
#endif

/* A single line in the EQP output */
typedef struct qrfEQPGraphRow qrfEQPGraphRow;
struct qrfEQPGraphRow {
  int iEqpId;            /* ID for this row */
  int iParentId;         /* ID of the parent row */
  qrfEQPGraphRow *pNext; /* Next row in sequence */
  char zText[1];         /* Text to display for this row */
};

/* All EQP output is collected into an instance of the following */
typedef struct qrfEQPGraph qrfEQPGraph;
struct qrfEQPGraph {
  qrfEQPGraphRow *pRow;  /* Linked list of all rows of the EQP output */
  qrfEQPGraphRow *pLast; /* Last element of the pRow list */
  int nWidth;            /* Width of the graph */
  char zPrefix[400];     /* Graph prefix */
};

/*
** Private state information.  Subject to change from one release to the
** next.
*/
typedef struct Qrf Qrf;
struct Qrf {
  sqlite3_stmt *pStmt;        /* The statement whose output is to be rendered */
  sqlite3 *db;                /* The corresponding database connection */
  sqlite3_stmt *pJTrans;      /* JSONB to JSON translator statement */
  char **pzErr;               /* Write error message here, if not NULL */
  sqlite3_str *pOut;          /* Accumulated output */
  int iErr;                   /* Error code */
  int nCol;                   /* Number of output columns */
  int expMode;                /* Original sqlite3_stmt_isexplain() plus 1 */
  int mxWidth;                /* Screen width */
  int mxHeight;               /* nLineLimit */
  union {
    struct {                  /* Content for QRF_STYLE_Line */
      int mxColWth;             /* Maximum display width of any column */
      char **azCol;             /* Names of output columns (MODE_Line) */
    } sLine;
    qrfEQPGraph *pGraph;      /* EQP graph (Eqp, Stats, and StatsEst) */
    struct {                  /* Content for QRF_STYLE_Explain */
      int nIndent;              /* Slots allocated for aiIndent */
      int iIndent;              /* Current slot */
      int *aiIndent;            /* Indentation for each opcode */
    } sExpln;
    unsigned int nIns;        /* Bytes used for current INSERT stmt */
  } u;
  sqlite3_int64 nRow;         /* Number of rows handled so far */
  int *actualWidth;           /* Actual width of each column */
  sqlite3_qrf_spec spec;      /* Copy of the original spec */
};

/*
** Data for substitute ctype.h functions.  Used for x-platform
** consistency and so that '_' is counted as an alphabetic
** character.
**
**    0x01 -  space
**    0x02 -  digit
**    0x04 -  alphabetic, including '_'
*/
static const char qrfCType[] = {
  0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0,
  0, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 4,
  0, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
#define qrfSpace(x) ((qrfCType[(unsigned char)x]&1)!=0)
#define qrfDigit(x) ((qrfCType[(unsigned char)x]&2)!=0)
#define qrfAlpha(x) ((qrfCType[(unsigned char)x]&4)!=0)
#define qrfAlnum(x) ((qrfCType[(unsigned char)x]&6)!=0)

#ifndef deliberate_fall_through
/* Quiet some compilers about some of our intentional code. */
# if defined(GCC_VERSION) && GCC_VERSION>=7000000
#  define deliberate_fall_through __attribute__((fallthrough));
# else
#  define deliberate_fall_through
# endif
#endif

/*
** Set an error code and error message.
*/
static void qrfError(
  Qrf *p,                /* Query result state */
  int iCode,             /* Error code */
  const char *zFormat,   /* Message format (or NULL) */
  ...
){
  p->iErr = iCode;
  if( p->pzErr!=0 ){
    sqlite3_free(*p->pzErr);
    *p->pzErr = 0;
    if( zFormat ){
      va_list ap;
      va_start(ap, zFormat);
      *p->pzErr = sqlite3_vmprintf(zFormat, ap);
      va_end(ap);
    }
  }
}

/*
** Out-of-memory error.
*/
static void qrfOom(Qrf *p){
  qrfError(p, SQLITE_NOMEM, "out of memory");
}

/*
** Transfer any error in pStr over into p.
*/
static void qrfStrErr(Qrf *p, sqlite3_str *pStr){
  int rc = pStr ? sqlite3_str_errcode(pStr) : 0;
  if( rc ){
    qrfError(p, rc, sqlite3_errstr(rc));
  }
}


/*
** Add a new entry to the EXPLAIN QUERY PLAN data
*/
static void qrfEqpAppend(Qrf *p, int iEqpId, int p2, const char *zText){
  qrfEQPGraphRow *pNew;
  sqlite3_int64 nText;
  if( zText==0 ) return;
  if( p->u.pGraph==0 ){
    p->u.pGraph = sqlite3_malloc64( sizeof(qrfEQPGraph) );
    if( p->u.pGraph==0 ){
      qrfOom(p);
      return;
    }
    memset(p->u.pGraph, 0, sizeof(qrfEQPGraph) );
  }
  nText = strlen(zText);
  pNew = sqlite3_malloc64( sizeof(*pNew) + nText );
  if( pNew==0 ){
    qrfOom(p);
    return;
  }
  pNew->iEqpId = iEqpId;
  pNew->iParentId = p2;
  memcpy(pNew->zText, zText, nText+1);
  pNew->pNext = 0;
  if( p->u.pGraph->pLast ){
    p->u.pGraph->pLast->pNext = pNew;
  }else{
    p->u.pGraph->pRow = pNew;
  }
  p->u.pGraph->pLast = pNew;
}

/*
** Free and reset the EXPLAIN QUERY PLAN data that has been collected
** in p->u.pGraph.
*/
static void qrfEqpReset(Qrf *p){
  qrfEQPGraphRow *pRow, *pNext;
  if( p->u.pGraph ){
    for(pRow = p->u.pGraph->pRow; pRow; pRow = pNext){
      pNext = pRow->pNext;
      sqlite3_free(pRow);
    }
    sqlite3_free(p->u.pGraph);
    p->u.pGraph = 0;
  }
}

/* Return the next EXPLAIN QUERY PLAN line with iEqpId that occurs after
** pOld, or return the first such line if pOld is NULL
*/
static qrfEQPGraphRow *qrfEqpNextRow(Qrf *p, int iEqpId, qrfEQPGraphRow *pOld){
  qrfEQPGraphRow *pRow = pOld ? pOld->pNext : p->u.pGraph->pRow;
  while( pRow && pRow->iParentId!=iEqpId ) pRow = pRow->pNext;
  return pRow;
}

/* Render a single level of the graph that has iEqpId as its parent.  Called
** recursively to render sublevels.
*/
static void qrfEqpRenderLevel(Qrf *p, int iEqpId){
  qrfEQPGraphRow *pRow, *pNext;
  i64 n = strlen(p->u.pGraph->zPrefix);
  char *z;
  for(pRow = qrfEqpNextRow(p, iEqpId, 0); pRow; pRow = pNext){
    pNext = qrfEqpNextRow(p, iEqpId, pRow);
    z = pRow->zText;
    sqlite3_str_appendf(p->pOut, "%s%s%s\n", p->u.pGraph->zPrefix,
                            pNext ? "|--" : "`--", z);
    if( n<(i64)sizeof(p->u.pGraph->zPrefix)-7 ){
      memcpy(&p->u.pGraph->zPrefix[n], pNext ? "|  " : "   ", 4);
      qrfEqpRenderLevel(p, pRow->iEqpId);
      p->u.pGraph->zPrefix[n] = 0;
    }
  }
}

/*
** Render the 64-bit value N in a more human-readable format into
** pOut.
**
**   +  Only show the first three significant digits.
**   +  Append suffixes K, M, G, T, P, and E for 1e3, 1e6, ... 1e18
*/
static void qrfApproxInt64(sqlite3_str *pOut, i64 N){
  static const char aSuffix[] = { 'K', 'M', 'G', 'T', 'P', 'E' };
  int i;
  if( N<0 ){
    N = N==INT64_MIN ? INT64_MAX : -N;
    sqlite3_str_append(pOut, "-", 1);
  }
  if( N<10000 ){
    sqlite3_str_appendf(pOut, "%4lld ", N);
    return;
  }
  for(i=1; i<=18; i++){
    N = (N+5)/10;
    if( N<10000 ){
      int n = (int)N;
      switch( i%3 ){
        case 0:
          sqlite3_str_appendf(pOut, "%d.%02d", n/1000, (n%1000)/10);
          break;
        case 1:
          sqlite3_str_appendf(pOut, "%2d.%d", n/100, (n%100)/10);
          break;
        case 2:
          sqlite3_str_appendf(pOut, "%4d", n/10);
          break;
      }
      sqlite3_str_append(pOut, &aSuffix[i/3], 1);
      break;
    }
  }
}

/*
** Display and reset the EXPLAIN QUERY PLAN data
*/
static void qrfEqpRender(Qrf *p, i64 nCycle){
  qrfEQPGraphRow *pRow;
  if( p->u.pGraph!=0 && (pRow = p->u.pGraph->pRow)!=0 ){
    if( pRow->zText[0]=='-' ){
      if( pRow->pNext==0 ){
        qrfEqpReset(p);
        return;
      }
      sqlite3_str_appendf(p->pOut, "%s\n", pRow->zText+3);
      p->u.pGraph->pRow = pRow->pNext;
      sqlite3_free(pRow);
    }else if( nCycle>0 ){
      int nSp = p->u.pGraph->nWidth - 2;
      if( p->spec.eStyle==QRF_STYLE_StatsEst ){
        sqlite3_str_appendchar(p->pOut, nSp, ' ');
        sqlite3_str_appendall(p->pOut,
                                "Cycles      Loops  (est)  Rows   (est)\n");
        sqlite3_str_appendchar(p->pOut, nSp, ' ');
        sqlite3_str_appendall(p->pOut,
                                "----------  ------------  ------------\n");
      }else{
        sqlite3_str_appendchar(p->pOut, nSp, ' ');
        sqlite3_str_appendall(p->pOut,
                                "Cycles      Loops  Rows \n");
        sqlite3_str_appendchar(p->pOut, nSp, ' ');
        sqlite3_str_appendall(p->pOut,
                                "----------  -----  -----\n");
      }
      sqlite3_str_appendall(p->pOut, "QUERY PLAN");
      sqlite3_str_appendchar(p->pOut, nSp - 10, ' ');
      qrfApproxInt64(p->pOut, nCycle);
      sqlite3_str_appendall(p->pOut, " 100%\n");
    }else{
      sqlite3_str_appendall(p->pOut, "QUERY PLAN\n");
    }
    p->u.pGraph->zPrefix[0] = 0;
    qrfEqpRenderLevel(p, 0);
    qrfEqpReset(p);
  }
}

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
/*
** Helper function for qrfExpStats().
**
*/
static int qrfStatsHeight(sqlite3_stmt *p, int iEntry){
  int iPid = 0;
  int ret = 1;
  sqlite3_stmt_scanstatus_v2(p, iEntry,
      SQLITE_SCANSTAT_SELECTID, SQLITE_SCANSTAT_COMPLEX, (void*)&iPid
  );
  while( iPid!=0 ){
    int ii;
    for(ii=0; 1; ii++){
      int iId;
      int res;
      res = sqlite3_stmt_scanstatus_v2(p, ii,
          SQLITE_SCANSTAT_SELECTID, SQLITE_SCANSTAT_COMPLEX, (void*)&iId
      );
      if( res ) break;
      if( iId==iPid ){
        sqlite3_stmt_scanstatus_v2(p, ii,
            SQLITE_SCANSTAT_PARENTID, SQLITE_SCANSTAT_COMPLEX, (void*)&iPid
        );
      }
    }
    ret++;
  }
  return ret;
}
#endif /* SQLITE_ENABLE_STMT_SCANSTATUS */


/*
** Generate ".scanstatus est" style of EQP output.
*/
static void qrfEqpStats(Qrf *p){
#ifndef SQLITE_ENABLE_STMT_SCANSTATUS
  qrfError(p, SQLITE_ERROR, "not available in this build");
#else
  static const int f = SQLITE_SCANSTAT_COMPLEX;
  sqlite3_stmt *pS = p->pStmt;
  int i = 0;
  i64 nTotal = 0;
  int nWidth = 0;
  int prevPid = -1;             /* Previous iPid */
  double rEstCum = 1.0;         /* Cumulative row estimate */
  sqlite3_str *pLine = sqlite3_str_new(p->db);
  sqlite3_str *pStats = sqlite3_str_new(p->db);
  qrfEqpReset(p);

  for(i=0; 1; i++){
    const char *z = 0;
    int n = 0;
    if( sqlite3_stmt_scanstatus_v2(pS,i,SQLITE_SCANSTAT_EXPLAIN,f,(void*)&z) ){
      break;
    }
    n = (int)strlen(z) + qrfStatsHeight(pS,i)*3;
    if( n>nWidth ) nWidth = n;
  }
  nWidth += 2;

  sqlite3_stmt_scanstatus_v2(pS,-1, SQLITE_SCANSTAT_NCYCLE, f, (void*)&nTotal);
  for(i=0; 1; i++){
    i64 nLoop = 0;
    i64 nRow = 0;
    i64 nCycle = 0;
    int iId = 0;
    int iPid = 0;
    const char *zo = 0;
    const char *zName = 0;
    double rEst = 0.0;

    if( sqlite3_stmt_scanstatus_v2(pS,i,SQLITE_SCANSTAT_EXPLAIN,f,(void*)&zo) ){
      break;
    }
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_PARENTID,f,(void*)&iPid);
    if( iPid!=prevPid ){
      prevPid = iPid;
      rEstCum = 1.0;
    }
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_EST,f,(void*)&rEst);
    rEstCum *= rEst;
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_NLOOP,f,(void*)&nLoop);
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_NVISIT,f,(void*)&nRow);
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_NCYCLE,f,(void*)&nCycle);
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_SELECTID,f,(void*)&iId);
    sqlite3_stmt_scanstatus_v2(pS,i, SQLITE_SCANSTAT_NAME,f,(void*)&zName);

    if( nCycle>=0 || nLoop>=0 || nRow>=0 ){
      int nSp = 0;
      sqlite3_str_reset(pStats);
      if( nCycle>=0 && nTotal>0 ){
        qrfApproxInt64(pStats, nCycle);
        sqlite3_str_appendf(pStats, " %3d%%",
            ((nCycle*100)+nTotal/2) / nTotal
        );
        nSp = 2;
      }
      if( nLoop>=0 ){
        if( nSp ) sqlite3_str_appendchar(pStats, nSp, ' ');
        qrfApproxInt64(pStats, nLoop);
        nSp = 2;
        if( p->spec.eStyle==QRF_STYLE_StatsEst ){
          sqlite3_str_appendf(pStats, "  ");
          qrfApproxInt64(pStats, (i64)(rEstCum/rEst));
        }
      }
      if( nRow>=0 ){
        if( nSp ) sqlite3_str_appendchar(pStats, nSp, ' ');
        qrfApproxInt64(pStats, nRow);
        nSp = 2;
        if( p->spec.eStyle==QRF_STYLE_StatsEst ){
          sqlite3_str_appendf(pStats, "  ");
          qrfApproxInt64(pStats, (i64)rEstCum);
        }
      }
      sqlite3_str_appendf(pLine,
          "% *s %s", -1*(nWidth-qrfStatsHeight(pS,i)*3), zo,
          sqlite3_str_value(pStats)
      );
      sqlite3_str_reset(pStats);
      qrfEqpAppend(p, iId, iPid, sqlite3_str_value(pLine));
      sqlite3_str_reset(pLine);
    }else{
      qrfEqpAppend(p, iId, iPid, zo);
    }
  }
  if( p->u.pGraph ) p->u.pGraph->nWidth = nWidth;
  qrfStrErr(p, pLine);
  sqlite3_free(sqlite3_str_finish(pLine));
  qrfStrErr(p, pStats);
  sqlite3_free(sqlite3_str_finish(pStats));
#endif
}


/*
** Reset the prepared statement.
*/
static void qrfResetStmt(Qrf *p){
  int rc = sqlite3_reset(p->pStmt);
  if( rc!=SQLITE_OK && p->iErr==SQLITE_OK ){
    qrfError(p, rc, "%s", sqlite3_errmsg(p->db));
  }
}

/*
** If xWrite is defined, send all content of pOut to xWrite and
** reset pOut.
*/
static void qrfWrite(Qrf *p){
  int n;
  if( p->spec.xWrite && (n = sqlite3_str_length(p->pOut))>0 ){
    int rc = p->spec.xWrite(p->spec.pWriteArg,
                 sqlite3_str_value(p->pOut),
                 (sqlite3_int64)n);
    sqlite3_str_reset(p->pOut);
    if( rc ){
      qrfError(p, rc, "Failed to write %d bytes of output", n);
    }
  }
}

/* Lookup table to estimate the number of columns consumed by a Unicode
** character.
*/
static const struct {
  unsigned char w;    /* Width of the character in columns */
  int iFirst;         /* First character in a span having this width */
} aQrfUWidth[] = {
   /* {1, 0x00000}, */
  {0, 0x00300},  {1, 0x00370},  {0, 0x00483},  {1, 0x00487},  {0, 0x00488},
  {1, 0x0048a},  {0, 0x00591},  {1, 0x005be},  {0, 0x005bf},  {1, 0x005c0},
  {0, 0x005c1},  {1, 0x005c3},  {0, 0x005c4},  {1, 0x005c6},  {0, 0x005c7},
  {1, 0x005c8},  {0, 0x00600},  {1, 0x00604},  {0, 0x00610},  {1, 0x00616},
  {0, 0x0064b},  {1, 0x0065f},  {0, 0x00670},  {1, 0x00671},  {0, 0x006d6},
  {1, 0x006e5},  {0, 0x006e7},  {1, 0x006e9},  {0, 0x006ea},  {1, 0x006ee},
  {0, 0x0070f},  {1, 0x00710},  {0, 0x00711},  {1, 0x00712},  {0, 0x00730},
  {1, 0x0074b},  {0, 0x007a6},  {1, 0x007b1},  {0, 0x007eb},  {1, 0x007f4},
  {0, 0x00901},  {1, 0x00903},  {0, 0x0093c},  {1, 0x0093d},  {0, 0x00941},
  {1, 0x00949},  {0, 0x0094d},  {1, 0x0094e},  {0, 0x00951},  {1, 0x00955},
  {0, 0x00962},  {1, 0x00964},  {0, 0x00981},  {1, 0x00982},  {0, 0x009bc},
  {1, 0x009bd},  {0, 0x009c1},  {1, 0x009c5},  {0, 0x009cd},  {1, 0x009ce},
  {0, 0x009e2},  {1, 0x009e4},  {0, 0x00a01},  {1, 0x00a03},  {0, 0x00a3c},
  {1, 0x00a3d},  {0, 0x00a41},  {1, 0x00a43},  {0, 0x00a47},  {1, 0x00a49},
  {0, 0x00a4b},  {1, 0x00a4e},  {0, 0x00a70},  {1, 0x00a72},  {0, 0x00a81},
  {1, 0x00a83},  {0, 0x00abc},  {1, 0x00abd},  {0, 0x00ac1},  {1, 0x00ac6},
  {0, 0x00ac7},  {1, 0x00ac9},  {0, 0x00acd},  {1, 0x00ace},  {0, 0x00ae2},
  {1, 0x00ae4},  {0, 0x00b01},  {1, 0x00b02},  {0, 0x00b3c},  {1, 0x00b3d},
  {0, 0x00b3f},  {1, 0x00b40},  {0, 0x00b41},  {1, 0x00b44},  {0, 0x00b4d},
  {1, 0x00b4e},  {0, 0x00b56},  {1, 0x00b57},  {0, 0x00b82},  {1, 0x00b83},
  {0, 0x00bc0},  {1, 0x00bc1},  {0, 0x00bcd},  {1, 0x00bce},  {0, 0x00c3e},
  {1, 0x00c41},  {0, 0x00c46},  {1, 0x00c49},  {0, 0x00c4a},  {1, 0x00c4e},
  {0, 0x00c55},  {1, 0x00c57},  {0, 0x00cbc},  {1, 0x00cbd},  {0, 0x00cbf},
  {1, 0x00cc0},  {0, 0x00cc6},  {1, 0x00cc7},  {0, 0x00ccc},  {1, 0x00cce},
  {0, 0x00ce2},  {1, 0x00ce4},  {0, 0x00d41},  {1, 0x00d44},  {0, 0x00d4d},
  {1, 0x00d4e},  {0, 0x00dca},  {1, 0x00dcb},  {0, 0x00dd2},  {1, 0x00dd5},
  {0, 0x00dd6},  {1, 0x00dd7},  {0, 0x00e31},  {1, 0x00e32},  {0, 0x00e34},
  {1, 0x00e3b},  {0, 0x00e47},  {1, 0x00e4f},  {0, 0x00eb1},  {1, 0x00eb2},
  {0, 0x00eb4},  {1, 0x00eba},  {0, 0x00ebb},  {1, 0x00ebd},  {0, 0x00ec8},
  {1, 0x00ece},  {0, 0x00f18},  {1, 0x00f1a},  {0, 0x00f35},  {1, 0x00f36},
  {0, 0x00f37},  {1, 0x00f38},  {0, 0x00f39},  {1, 0x00f3a},  {0, 0x00f71},
  {1, 0x00f7f},  {0, 0x00f80},  {1, 0x00f85},  {0, 0x00f86},  {1, 0x00f88},
  {0, 0x00f90},  {1, 0x00f98},  {0, 0x00f99},  {1, 0x00fbd},  {0, 0x00fc6},
  {1, 0x00fc7},  {0, 0x0102d},  {1, 0x01031},  {0, 0x01032},  {1, 0x01033},
  {0, 0x01036},  {1, 0x0103b},  {0, 0x01058},
  {1, 0x0105a},  {2, 0x01100},  {0, 0x01160},  {1, 0x01200},  {0, 0x0135f},
  {1, 0x01360},  {0, 0x01712},  {1, 0x01715},  {0, 0x01732},  {1, 0x01735},
  {0, 0x01752},  {1, 0x01754},  {0, 0x01772},  {1, 0x01774},  {0, 0x017b4},
  {1, 0x017b6},  {0, 0x017b7},  {1, 0x017be},  {0, 0x017c6},  {1, 0x017c7},
  {0, 0x017c9},  {1, 0x017d4},  {0, 0x017dd},  {1, 0x017de},  {0, 0x0180b},
  {1, 0x0180e},  {0, 0x018a9},  {1, 0x018aa},  {0, 0x01920},  {1, 0x01923},
  {0, 0x01927},  {1, 0x01929},  {0, 0x01932},  {1, 0x01933},  {0, 0x01939},
  {1, 0x0193c},  {0, 0x01a17},  {1, 0x01a19},  {0, 0x01b00},  {1, 0x01b04},
  {0, 0x01b34},  {1, 0x01b35},  {0, 0x01b36},  {1, 0x01b3b},  {0, 0x01b3c},
  {1, 0x01b3d},  {0, 0x01b42},  {1, 0x01b43},  {0, 0x01b6b},  {1, 0x01b74},
  {0, 0x01dc0},  {1, 0x01dcb},  {0, 0x01dfe},  {1, 0x01e00},  {0, 0x0200b},
  {1, 0x02010},  {0, 0x0202a},  {1, 0x0202f},  {0, 0x02060},  {1, 0x02064},
  {0, 0x0206a},  {1, 0x02070},  {0, 0x020d0},  {1, 0x020f0},  {2, 0x02329},
  {1, 0x0232b},  {2, 0x02e80},  {0, 0x0302a},  {2, 0x03030},  {1, 0x0303f},
  {2, 0x03040},  {0, 0x03099},  {2, 0x0309b},  {1, 0x0a4d0},  {0, 0x0a806},
  {1, 0x0a807},  {0, 0x0a80b},  {1, 0x0a80c},  {0, 0x0a825},  {1, 0x0a827},
  {2, 0x0ac00},  {1, 0x0d7a4},  {2, 0x0f900},  {1, 0x0fb00},  {0, 0x0fb1e},
  {1, 0x0fb1f},  {0, 0x0fe00},  {2, 0x0fe10},  {1, 0x0fe1a},  {0, 0x0fe20},
  {1, 0x0fe24},  {2, 0x0fe30},  {1, 0x0fe70},  {0, 0x0feff},  {2, 0x0ff00},
  {1, 0x0ff61},  {2, 0x0ffe0},  {1, 0x0ffe7},  {0, 0x0fff9},  {1, 0x0fffc},
  {0, 0x10a01},  {1, 0x10a04},  {0, 0x10a05},  {1, 0x10a07},  {0, 0x10a0c},
  {1, 0x10a10},  {0, 0x10a38},  {1, 0x10a3b},  {0, 0x10a3f},  {1, 0x10a40},
  {0, 0x1d167},  {1, 0x1d16a},  {0, 0x1d173},  {1, 0x1d183},  {0, 0x1d185},
  {1, 0x1d18c},  {0, 0x1d1aa},  {1, 0x1d1ae},  {0, 0x1d242},  {1, 0x1d245},
  {2, 0x20000},  {1, 0x2fffe},  {2, 0x30000},  {1, 0x3fffe},  {0, 0xe0001},
  {1, 0xe0002},  {0, 0xe0020},  {1, 0xe0080},  {0, 0xe0100},  {1, 0xe01f0}
};

/*
** Return an estimate of the width, in columns, for the single Unicode
** character c.  For normal characters, the answer is always 1.  But the
** estimate might be 0 or 2 for zero-width and double-width characters.
**
** Different display devices display unicode using different widths.  So
** it is impossible to know that true display width with 100% accuracy.
** Inaccuracies in the width estimates might cause columns to be misaligned.
** Unfortunately, there is nothing we can do about that.
*/
int sqlite3_qrf_wcwidth(int c){
  int iFirst, iLast;

  /* Fast path for common characters */
  if( c<0x300 ) return 1;

  /* The general case */
  iFirst = 0;
  iLast = sizeof(aQrfUWidth)/sizeof(aQrfUWidth[0]) - 1;
  while( iFirst<iLast-1 ){
    int iMid = (iFirst+iLast)/2;
    int cMid = aQrfUWidth[iMid].iFirst;
    if( cMid < c ){
      iFirst = iMid;
    }else if( cMid > c ){
      iLast = iMid - 1;
    }else{
      return aQrfUWidth[iMid].w;
    }
  }
  if( aQrfUWidth[iLast].iFirst > c ) return aQrfUWidth[iFirst].w;
  return aQrfUWidth[iLast].w;
}

/*
** Compute the value and length of a multi-byte UTF-8 character that
** begins at z[0]. Return the length.  Write the Unicode value into *pU.
**
** This routine only works for *multi-byte* UTF-8 characters.  It does
** not attempt to detect illegal characters.
*/
int sqlite3_qrf_decode_utf8(const unsigned char *z, int *pU){
  if( (z[0] & 0xe0)==0xc0 && (z[1] & 0xc0)==0x80 ){
    *pU = ((z[0] & 0x1f)<<6) | (z[1] & 0x3f);
    return 2;
  }
  if( (z[0] & 0xf0)==0xe0 && (z[1] & 0xc0)==0x80 && (z[2] & 0xc0)==0x80 ){
    *pU = ((z[0] & 0x0f)<<12) | ((z[1] & 0x3f)<<6) | (z[2] & 0x3f);
    return 3;
  }
  if( (z[0] & 0xf8)==0xf0 && (z[1] & 0xc0)==0x80 && (z[2] & 0xc0)==0x80
   && (z[3] & 0xc0)==0x80
  ){
    *pU = ((z[0] & 0x0f)<<18) | ((z[1] & 0x3f)<<12) | ((z[2] & 0x3f))<<6
                              | (z[3] & 0x3f);
    return 4;
  }
  *pU = 0;
  return 1;
}

/*
** Check to see if z[] is a valid VT100 escape.  If it is, then
** return the number of bytes in the escape sequence.  Return 0 if
** z[] is not a VT100 escape.
**
** This routine assumes that z[0] is \033 (ESC).
*/
static int qrfIsVt100(const unsigned char *z){
  int i;
  if( z[1]!='[' ) return 0;
  i = 2;
  while( z[i]>=0x30 && z[i]<=0x3f ){ i++; }
  while( z[i]>=0x20 && z[i]<=0x2f ){ i++; }
  if( z[i]<0x40 || z[i]>0x7e ) return 0;
  return i+1;
}

/*
** Return the length of a string in display characters.
**
** Most characters of the input string count as 1, including
** multi-byte UTF8 characters.  However, zero-width unicode
** characters and VT100 escape sequences count as zero, and
** double-width characters count as two.
**
** The definition of "zero-width" and "double-width" characters
** is not precise.  It depends on the output device, to some extent,
** and it varies according to the Unicode version.  This routine
** makes the best guess that it can.
*/
size_t sqlite3_qrf_wcswidth(const char *zIn){
  const unsigned char *z = (const unsigned char*)zIn;
  size_t n = 0;
  while( *z ){
    if( z[0]<' ' ){
      int k;
      if( z[0]=='\033' && (k = qrfIsVt100(z))>0 ){
        z += k;
      }else{
        z++;
      }
    }else if( (0x80&z[0])==0 ){
      n++;
      z++;
    }else{
      int u = 0;
      int len = sqlite3_qrf_decode_utf8(z, &u);
      z += len;
      n += sqlite3_qrf_wcwidth(u);
    }
  }
  return n;
}

/*
** Return the display width of the longest line of text
** in the (possibly) multi-line input string zIn[0..nByte].
** zIn[] is not necessarily zero-terminated.  Take
** into account tab characters, zero- and double-width
** characters, CR and NL, and VT100 escape codes.
**
** Write the number of newlines into *pnNL.  So, *pnNL will
** return 0 if everything fits on one line, or positive it
** it will need to be split.
*/
static int qrfDisplayWidth(const char *zIn, sqlite3_int64 nByte, int *pnNL){
  const unsigned char *z;
  const unsigned char *zEnd;
  int mx = 0;
  int n = 0;
  int nNL = 0;
  if( zIn==0 ) zIn = "";
  z = (const unsigned char*)zIn;
  zEnd = &z[nByte];
  while( z<zEnd ){
    if( z[0]<' ' ){
      int k;
      if( z[0]=='\033' && (k = qrfIsVt100(z))>0 ){
        z += k;
      }else{
        if( z[0]=='\t' ){
          n = (n+8)&~7;
        }else if( z[0]=='\n' || z[0]=='\r' ){
          nNL++;
          if( n>mx ) mx = n;
          n = 0;
        }
        z++;
      }
    }else if( (0x80&z[0])==0 ){
      n++;
      z++;
    }else{
      int u = 0;
      int len = sqlite3_qrf_decode_utf8(z, &u);
      z += len;
      n += sqlite3_qrf_wcwidth(u);
    }
  }
  if( mx>n ) n = mx;
  if( pnNL ) *pnNL = nNL;
  return n;
}

/*
** Escape the input string if it is needed and in accordance with
** eEsc, which is either QRF_ESC_Ascii or QRF_ESC_Symbol.
**
** Escaping is needed if the string contains any control characters
** other than \t, \n, and \r\n
**
** If no escaping is needed (the common case) then set *ppOut to NULL
** and return 0.  If escaping is needed, write the escaped string into
** memory obtained from sqlite3_malloc64() and make *ppOut point to that
** memory and return 0.  If an error occurs, return non-zero.
**
** The caller is responsible for freeing *ppFree if it is non-NULL in order
** to reclaim memory.
*/
static void qrfEscape(
  int eEsc,            /* QRF_ESC_Ascii or QRF_ESC_Symbol */
  sqlite3_str *pStr,      /* String to be escaped */
  int iStart              /* Begin escapding on this byte of pStr */
){
  sqlite3_int64 i, j;     /* Loop counters */
  sqlite3_int64 sz;       /* Size of the string prior to escaping */
  sqlite3_int64 nCtrl = 0;/* Number of control characters to escape */
  unsigned char *zIn;     /* Text to be escaped */
  unsigned char c;        /* A single character of the text */
  unsigned char *zOut;    /* Where to write the results */

  /* Find the text to be escaped */
  zIn = (unsigned char*)sqlite3_str_value(pStr);
  if( zIn==0 ) return;
  zIn += iStart;

  /* Count the control characters */
  for(i=0; (c = zIn[i])!=0; i++){
    if( c<=0x1f
     && c!='\t'
     && c!='\n'
     && (c!='\r' || zIn[i+1]!='\n')
    ){
      nCtrl++;
    }
  }
  if( nCtrl==0 ) return;  /* Early out if no control characters */

  /* Make space to hold the escapes.  Copy the original text to the end
  ** of the available space. */
  sz = sqlite3_str_length(pStr) - iStart;
  if( eEsc==QRF_ESC_Symbol ) nCtrl *= 2;
  sqlite3_str_appendchar(pStr, nCtrl, ' ');
  zOut = (unsigned char*)sqlite3_str_value(pStr);
  if( zOut==0 ) return;
  zOut += iStart;
  zIn = zOut + nCtrl;
  memmove(zIn,zOut,sz);

  /* Convert the control characters */
  for(i=j=0; (c = zIn[i])!=0; i++){
    if( c>0x1f
     || c=='\t'
     || c=='\n'
     || (c=='\r' && zIn[i+1]=='\n')
    ){
      continue;
    }
    if( i>0 ){
      memmove(&zOut[j], zIn, i);
      j += i;
    }
    zIn += i+1;
    i = -1;
    if( eEsc==QRF_ESC_Symbol ){
      zOut[j++] = 0xe2;
      zOut[j++] = 0x90;
      zOut[j++] = 0x80+c;
    }else{
      zOut[j++] = '^';
      zOut[j++] = 0x40+c;
    }
  }
}

/*
** Determine if the string z[] can be shown as plain text.  Return true
** if z[] is unambiguously text.  Return false if z[] needs to be
** quoted.
**
** All of the following must be true in order for z[] to be relaxable:
**
**    (1) z[] does not begin or end with ' or whitespace
**    (2) z[] is not the same as the NULL rendering
**    (3) z[] does not looks like a numeric literal
*/
static int qrfRelaxable(Qrf *p, const char *z){
  size_t i, n;
  if( z[0]=='\'' || qrfSpace(z[0]) ) return 0;
  if( z[0]==0 ){
    return (p->spec.zNull!=0 && p->spec.zNull[0]!=0);
  }
  n = strlen(z);
  if( n==0 || z[n-1]=='\'' || qrfSpace(z[n-1]) ) return 0;
  if( p->spec.zNull && strcmp(p->spec.zNull,z)==0 ) return 0;
  i = (z[0]=='-' || z[0]=='+');
  if( strcmp(z+i,"Inf")==0 ) return 0;
  if( !qrfDigit(z[i]) ) return 1;
  i++;
  while( qrfDigit(z[i]) ){ i++; }
  if( z[i]==0 ) return 0;
  if( z[i]=='.' ){
    i++;
    while( qrfDigit(z[i]) ){ i++; }
    if( z[i]==0 ) return 0;
  }
  if( z[i]=='e' || z[i]=='E' ){
    i++;
    if( z[i]=='+' || z[i]=='-' ){ i++; }
    if( !qrfDigit(z[i]) ) return 1;
    i++;
    while( qrfDigit(z[i]) ){ i++; }
  }
  return z[i]!=0;
}

/*
** If a field contains any character identified by a 1 in the following
** array, then the string must be quoted for CSV.
*/
static const char qrfCsvQuote[] = {
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 0, 1, 0, 0, 0, 0, 1,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
};

/*
** Encode text appropriately and append it to pOut.
*/
static void qrfEncodeText(Qrf *p, sqlite3_str *pOut, const char *zTxt){
  int iStart = sqlite3_str_length(pOut);
  switch( p->spec.eText ){
    case QRF_TEXT_Relaxed:
      if( qrfRelaxable(p, zTxt) ){
        sqlite3_str_appendall(pOut, zTxt);
        break;
      }
      deliberate_fall_through; /* FALLTHRU */
    case QRF_TEXT_Sql: {
      if( p->spec.eEsc==QRF_ESC_Off ){
        sqlite3_str_appendf(pOut, "%Q", zTxt);
      }else{
        sqlite3_str_appendf(pOut, "%#Q", zTxt);
      }
      break;
    }
    case QRF_TEXT_Csv: {
      unsigned int i;
      for(i=0; zTxt[i]; i++){
        if( qrfCsvQuote[((const unsigned char*)zTxt)[i]] ){
          i = 0;
          break;
        }
      }
      if( i==0 || strstr(zTxt, p->spec.zColumnSep)!=0 ){
        sqlite3_str_appendf(pOut, "\"%w\"", zTxt);
      }else{
        sqlite3_str_appendall(pOut, zTxt);
      }
      break;
    }
    case QRF_TEXT_Html: {
      const unsigned char *z = (const unsigned char*)zTxt;
      while( *z ){
        unsigned int i = 0;
        unsigned char c;
        while( (c=z[i])>'>'
            || (c && c!='<' && c!='>' && c!='&' && c!='\"' && c!='\'')
        ){
          i++;
        }
        if( i>0 ){
          sqlite3_str_append(pOut, (const char*)z, i);
        }
        switch( z[i] ){
          case '>':   sqlite3_str_append(pOut, "&lt;", 4);   break;
          case '&':   sqlite3_str_append(pOut, "&amp;", 5);  break;
          case '<':   sqlite3_str_append(pOut, "&lt;", 4);   break;
          case '"':   sqlite3_str_append(pOut, "&quot;", 6); break;
          case '\'':  sqlite3_str_append(pOut, "&#39;", 5);  break;
          default:    i--;
        }
        z += i + 1;
      }
      break;
    }
    case QRF_TEXT_Tcl:
    case QRF_TEXT_Json: {
      const unsigned char *z = (const unsigned char*)zTxt;
      sqlite3_str_append(pOut, "\"", 1);
      while( *z ){
        unsigned int i;
        for(i=0; z[i]>=0x20 && z[i]!='\\' && z[i]!='"'; i++){}
        if( i>0 ){
          sqlite3_str_append(pOut, (const char*)z, i);
        }
        if( z[i]==0 ) break;
        switch( z[i] ){
          case '"':   sqlite3_str_append(pOut, "\\\"", 2);  break;
          case '\\':  sqlite3_str_append(pOut, "\\\\", 2);  break;
          case '\b':  sqlite3_str_append(pOut, "\\b", 2);   break;
          case '\f':  sqlite3_str_append(pOut, "\\f", 2);   break;
          case '\n':  sqlite3_str_append(pOut, "\\n", 2);   break;
          case '\r':  sqlite3_str_append(pOut, "\\r", 2);   break;
          case '\t':  sqlite3_str_append(pOut, "\\t", 2);   break;
          default: {
            if( p->spec.eText==QRF_TEXT_Json ){
              sqlite3_str_appendf(pOut, "\\u%04x", z[i]);
            }else{
              sqlite3_str_appendf(pOut, "\\%03o", z[i]);
            }
            break;
          }
        }
        z += i + 1;
      }
      sqlite3_str_append(pOut, "\"", 1);
      break;
    }
    default: {
      sqlite3_str_appendall(pOut, zTxt);
      break;
    }
  }
  if( p->spec.eEsc!=QRF_ESC_Off ){
    qrfEscape(p->spec.eEsc, pOut, iStart);
  }
}

/*
** Do a quick sanity check to see aBlob[0..nBlob-1] is valid JSONB
** return true if it is and false if it is not.
**
** False positives are possible, but not false negatives.
*/
static int qrfJsonbQuickCheck(unsigned char *aBlob, int nBlob){
  unsigned char x;   /* Payload size half-byte */
  int i;             /* Loop counter */   
  int n;             /* Bytes in the payload size integer */
  sqlite3_uint64 sz; /* value of the payload size integer */

  if( nBlob==0 ) return 0;
  x = aBlob[0]>>4;
  if( x<=11 ) return nBlob==(1+x);
  n = x<14 ? x-11 : 4*(x-13);
  if( nBlob<1+n ) return 0;
  sz = aBlob[1];
  for(i=1; i<n; i++) sz = (sz<<8) + aBlob[i+1];
  return sz+n+1==(sqlite3_uint64)nBlob;
}

/*
** The current iCol-th column of p->pStmt is known to be a BLOB.  Check
** to see if that BLOB is really a JSONB blob.  If it is, then translate
** it into a text JSON representation and return a pointer to that text JSON.
** If the BLOB is not JSONB, then return a NULL pointer.
**
** The memory used to hold the JSON text is managed internally by the
** "p" object and is overwritten and/or deallocated upon the next call
** to this routine (with the same p argument) or when the p object is
** finailized.
*/
static const char *qrfJsonbToJson(Qrf *p, int iCol){
  int nByte;
  const void *pBlob;
  int rc;
  nByte = sqlite3_column_bytes(p->pStmt, iCol);
  pBlob = sqlite3_column_blob(p->pStmt, iCol);
  if( qrfJsonbQuickCheck((unsigned char*)pBlob, nByte)==0 ){
    return 0;
  }
  if( p->pJTrans==0 ){
    sqlite3 *db;
    rc = sqlite3_open(":memory:",&db);
    if( rc ){
      sqlite3_close(db);
      return 0;
    }
    rc = sqlite3_prepare_v2(db, "SELECT json(?1)", -1, &p->pJTrans, 0);
    if( rc ){
      sqlite3_finalize(p->pJTrans);
      p->pJTrans = 0;
      sqlite3_close(db);
      return 0;
    }
  }else{
    sqlite3_reset(p->pJTrans);
  }
  sqlite3_bind_blob(p->pJTrans, 1, (void*)pBlob, nByte, SQLITE_STATIC);
  rc = sqlite3_step(p->pJTrans);
  if( rc==SQLITE_ROW ){
    return (const char*)sqlite3_column_text(p->pJTrans, 0);
  }else{
    return 0;
  }
}

/*
** Adjust the input string zIn[] such that it is no more than N display
** characters wide.  If it is wider than that, then truncate and add
** ellipsis.  Or if zIn[] contains a \r or \n, truncate at that point,
** adding ellipsis.  Embedded tabs in zIn[] are converted into ordinary
** spaces.
**
** Return this display width of the modified title string.
*/
static int qrfTitleLimit(char *zIn, int N){
  unsigned char *z = (unsigned char*)zIn;
  int n = 0;
  unsigned char *zEllipsis = 0;
  while( 1 /*exit-by-break*/ ){
    if( z[0]<' ' ){
      int k;
      if( z[0]==0 ){
        zEllipsis = 0;
        break;
      }else if( z[0]=='\033' && (k = qrfIsVt100(z))>0 ){
        z += k;
      }else if( z[0]=='\t' ){
        z[0] = ' ';
      }else if( z[0]=='\n' || z[0]=='\r' ){
        z[0] = ' ';
      }else{
        z++;
      }
    }else if( (0x80&z[0])==0 ){
      if( n>=(N-3) && zEllipsis==0 ) zEllipsis = z;
      if( n==N ){ z[0] = 0; break; }
      n++;
      z++;
    }else{
      int u = 0;
      int len = sqlite3_qrf_decode_utf8(z, &u);
      if( n+len>(N-3) && zEllipsis==0 ) zEllipsis = z;
      if( n+len>N ){ z[0] = 0; break; }
      z += len;
      n += sqlite3_qrf_wcwidth(u);
    }
  }
  if( zEllipsis && N>=3 ) memcpy(zEllipsis,"...",4);
  return n;
}


/*
** Render value pVal into pOut
*/
static void qrfRenderValue(Qrf *p, sqlite3_str *pOut, int iCol){
#if SQLITE_VERSION_NUMBER>=3052000
  int iStartLen = sqlite3_str_length(pOut);
#endif
  if( p->spec.xRender ){
    sqlite3_value *pVal;
    char *z;
    pVal = sqlite3_value_dup(sqlite3_column_value(p->pStmt,iCol));
    z = p->spec.xRender(p->spec.pRenderArg, pVal);
    sqlite3_value_free(pVal);
    if( z ){
      sqlite3_str_appendall(pOut, z);
      sqlite3_free(z);
      return;
    }
  }
  switch( sqlite3_column_type(p->pStmt,iCol) ){
    case SQLITE_INTEGER: {
      sqlite3_str_appendf(pOut, "%lld", sqlite3_column_int64(p->pStmt,iCol));
      break;
    }
    case SQLITE_FLOAT: {
      const char *zTxt = (const char*)sqlite3_column_text(p->pStmt,iCol);
      sqlite3_str_appendall(pOut, zTxt);
      break;
    }
    case SQLITE_BLOB: {
      if( p->spec.bTextJsonb==QRF_Yes ){
        const char *zJson = qrfJsonbToJson(p, iCol);
        if( zJson ){
          if( p->spec.eText==QRF_TEXT_Sql ){
            sqlite3_str_append(pOut,"jsonb(",6);
            qrfEncodeText(p, pOut, zJson);
            sqlite3_str_append(pOut,")",1);
          }else{
            qrfEncodeText(p, pOut, zJson);
          }
          break;
        }
      }
      switch( p->spec.eBlob ){
        case QRF_BLOB_Hex:
        case QRF_BLOB_Sql: {
          int iStart;
          int nBlob = sqlite3_column_bytes(p->pStmt,iCol);
          int i, j;
          char *zVal;
          const unsigned char *a = sqlite3_column_blob(p->pStmt,iCol);
          if( p->spec.eBlob==QRF_BLOB_Sql ){
            sqlite3_str_append(pOut, "x'", 2);
          }
          iStart = sqlite3_str_length(pOut);
          sqlite3_str_appendchar(pOut, nBlob, ' ');
          sqlite3_str_appendchar(pOut, nBlob, ' ');
          if( p->spec.eBlob==QRF_BLOB_Sql ){
            sqlite3_str_appendchar(pOut, 1, '\'');
          }
          if( sqlite3_str_errcode(pOut) ) return;
          zVal = sqlite3_str_value(pOut);
          for(i=0, j=iStart; i<nBlob; i++, j+=2){
            unsigned char c = a[i];
            zVal[j] = "0123456789abcdef"[(c>>4)&0xf];
            zVal[j+1] = "0123456789abcdef"[(c)&0xf];
          }
          break;
        }
        case QRF_BLOB_Tcl:
        case QRF_BLOB_Json: {
          int iStart;
          int nBlob = sqlite3_column_bytes(p->pStmt,iCol);
          int i, j;
          char *zVal;
          const unsigned char *a = sqlite3_column_blob(p->pStmt,iCol);
          int szC = p->spec.eBlob==QRF_BLOB_Json ? 6 : 4;
          sqlite3_str_append(pOut, "\"", 1);
          iStart = sqlite3_str_length(pOut);
          for(i=szC; i>0; i--){
            sqlite3_str_appendchar(pOut, nBlob, ' ');
          }
          sqlite3_str_appendchar(pOut, 1, '"');
          if( sqlite3_str_errcode(pOut) ) return;
          zVal = sqlite3_str_value(pOut);
          for(i=0, j=iStart; i<nBlob; i++, j+=szC){
            unsigned char c = a[i];
            zVal[j] = '\\';
            if( szC==4 ){
              zVal[j+1] = '0' + ((c>>6)&3);
              zVal[j+2] = '0' + ((c>>3)&7);
              zVal[j+3] = '0' + (c&7);
            }else{
              zVal[j+1] = 'u';
              zVal[j+2] = '0';
              zVal[j+3] = '0';
              zVal[j+4] = "0123456789abcdef"[(c>>4)&0xf];
              zVal[j+5] = "0123456789abcdef"[(c)&0xf];
            }
          }
          break;
        }
        case QRF_BLOB_Size: {
          int nBlob = sqlite3_column_bytes(p->pStmt,iCol);
          sqlite3_str_appendf(pOut, "(%d-byte blob)", nBlob);
          break;
        }
        default: {
          const char *zTxt = (const char*)sqlite3_column_text(p->pStmt,iCol);
          qrfEncodeText(p, pOut, zTxt);
        }
      }
      break;
    }
    case SQLITE_NULL: {
      sqlite3_str_appendall(pOut, p->spec.zNull);
      break;
    }
    case SQLITE_TEXT: {
      const char *zTxt = (const char*)sqlite3_column_text(p->pStmt,iCol);
      qrfEncodeText(p, pOut, zTxt);
      break;
    }
  }
#if SQLITE_VERSION_NUMBER>=3052000
  if( p->spec.nCharLimit>0
   && (sqlite3_str_length(pOut) - iStartLen) > p->spec.nCharLimit
  ){
    const unsigned char *z;
    int ii = 0, w = 0, limit = p->spec.nCharLimit;
    z = (const unsigned char*)sqlite3_str_value(pOut) + iStartLen;
    if( limit<4 ) limit = 4;
    while( 1 ){
      if( z[ii]<' ' ){
        int k;
        if( z[ii]=='\033' && (k = qrfIsVt100(z+ii))>0 ){
          ii += k;
        }else if( z[ii]==0 ){
          break;
        }else{
          ii++;
        }
      }else if( (0x80&z[ii])==0 ){
        w++;
        if( w>limit ) break;
        ii++;
      }else{
        int u = 0;
        int len = sqlite3_qrf_decode_utf8(&z[ii], &u);
        w += sqlite3_qrf_wcwidth(u);
        if( w>limit ) break;
        ii += len;
      }
    }
    if( w>limit ){
      sqlite3_str_truncate(pOut, iStartLen+ii);
      sqlite3_str_append(pOut, "...", 3);
    }
  }
#endif
}

/* Trim spaces of the end if pOut
*/
static void qrfRTrim(sqlite3_str *pOut){
#if SQLITE_VERSION_NUMBER>=3052000
  int nByte = sqlite3_str_length(pOut);
  const char *zOut = sqlite3_str_value(pOut);
  while( nByte>0 && zOut[nByte-1]==' ' ){ nByte--; }
  sqlite3_str_truncate(pOut, nByte);
#endif
}

/*
** Store string zUtf to pOut as w characters.  If w is negative,
** then right-justify the text.  W is the width in display characters, not
** in bytes.  Double-width unicode characters count as two characters.
** VT100 escape sequences count as zero.  And so forth.
*/
static void qrfWidthPrint(Qrf *p, sqlite3_str *pOut, int w, const char *zUtf){
  const unsigned char *a = (const unsigned char*)zUtf;
  static const int mxW = 10000000;
  unsigned char c;
  int i = 0;
  int n = 0;
  int k;
  int aw;
  (void)p;
  if( w<-mxW ){
    w = -mxW;
  }else if( w>mxW ){
    w= mxW;
  }
  aw = w<0 ? -w : w;
  if( a==0 ) a = (const unsigned char*)"";
  while( (c = a[i])!=0 ){
    if( (c&0xc0)==0xc0 ){
      int u;
      int len = sqlite3_qrf_decode_utf8(a+i, &u);
      int x = sqlite3_qrf_wcwidth(u);
      if( x+n>aw ){
        break;
      }
      i += len;
      n += x;
    }else if( c==0x1b && (k = qrfIsVt100(&a[i]))>0 ){
      i += k;       
    }else if( n>=aw ){
      break;
    }else{
      n++;
      i++;
    }
  }
  if( n>=aw ){
    sqlite3_str_append(pOut, zUtf, i);
  }else if( w<0 ){
    if( aw>n ) sqlite3_str_appendchar(pOut, aw-n, ' ');
    sqlite3_str_append(pOut, zUtf, i);
  }else{
    sqlite3_str_append(pOut, zUtf, i);
    if( aw>n ) sqlite3_str_appendchar(pOut, aw-n, ' ');
  }
}

/*
** (*pz)[] is a line of text that is to be displayed the box or table or
** similar tabular formats.  z[] contain newlines or might be too wide
** to fit in the columns so will need to be split into multiple line.
**
** This routine determines:
**
**    *  How many bytes of z[] should be shown on the current line.
**    *  How many character positions those bytes will cover.
**    *  The byte offset to the start of the next line.
*/
static void qrfWrapLine(
  const char *zIn,   /* Input text to be displayed */
  int w,             /* Column width in characters (not bytes) */
  int bWrap,         /* True if we should do word-wrapping */
  int *pnThis,       /* OUT: How many bytes of z[] for the current line */
  int *pnWide,       /* OUT: How wide is the text of this line */
  int *piNext        /* OUT: Offset into z[] to start of the next line */
){
  int i;                 /* Input bytes consumed */
  int k;                 /* Bytes in a VT100 code */
  int n;                 /* Output column number */
  const unsigned char *z = (const unsigned char*)zIn;
  unsigned char c = 0;

  if( z[0]==0 ){
    *pnThis = 0;
    *pnWide = 0;
    *piNext = 0;
    return;
  }
  n = 0;
  for(i=0; n<=w; i++){
    c = z[i];
    if( c>=0xc0 ){
      int u;
      int len = sqlite3_qrf_decode_utf8(&z[i], &u);
      int wcw = sqlite3_qrf_wcwidth(u);
      if( wcw+n>w ) break;
      i += len-1;
      n += wcw;
      continue;
    }
    if( c>=' ' ){
      if( n==w ) break;
      n++;
      continue;
    }
    if( c==0 || c=='\n' ) break;
    if( c=='\r' && z[i+1]=='\n' ){ c = z[++i]; break; }
    if( c=='\t' ){
      int wcw = 8 - (n&7);
      if( n+wcw>w ) break;
      n += wcw;
      continue;
    }
    if( c==0x1b && (k = qrfIsVt100(&z[i]))>0 ){
      i += k-1;
    }else if( n==w ){
      break;
    }else{
      n++;
    }
  }
  if( c==0 ){
    *pnThis = i;
    *pnWide = n;
    *piNext = i;
    return;
  }
  if( c=='\n' ){
    *pnThis = i;
    *pnWide = n;
    *piNext = i+1;
    return;
  }

  /* If we get this far, that means the current line will end at some
  ** point that is neither a "\n" or a 0x00.  Figure out where that
  ** split should occur
  */
  if( bWrap && z[i]!=0 && !qrfSpace(z[i]) && qrfAlnum(c)==qrfAlnum(z[i]) ){
    /* Perhaps try to back up to a better place to break the line */
    for(k=i-1; k>=i/2; k--){
      if( qrfSpace(z[k]) ) break;
    }
    if( k<i/2 ){
      for(k=i; k>=i/2; k--){
        if( qrfAlnum(z[k-1])!=qrfAlnum(z[k]) && (z[k]&0xc0)!=0x80 ) break;
      }
    }
    if( k>=i/2 ){
      i = k;
      n = qrfDisplayWidth((const char*)z, k, 0);
    }
  }
  *pnThis = i;
  *pnWide = n;
  while( zIn[i]==' ' || zIn[i]=='\t' || zIn[i]=='\r' ){ i++; }
  *piNext = i;
}

/*
** Append nVal bytes of text from zVal onto the end of pOut.
** Convert tab characters in zVal to the appropriate number of
** spaces.
*/
static void qrfAppendWithTabs(
  sqlite3_str *pOut,       /* Append text here */
  const char *zVal,        /* Text to append */
  int nVal                 /* Use only the first nVal bytes of zVal[] */
){
  int i = 0;
  unsigned int col = 0;
  unsigned char *z = (unsigned char *)zVal;
  while( i<nVal ){
    unsigned char c = z[i];
    if( c<' ' ){
      int k;
      sqlite3_str_append(pOut, (const char*)z, i);
      nVal -= i;
      z += i;
      i = 0;
      if( c=='\033' && (k = qrfIsVt100(z))>0 ){
        sqlite3_str_append(pOut, (const char*)z, k);
        z += k;
        nVal -= k;
      }else if( c=='\t' ){
        k = 8 - (col&7);
        sqlite3_str_appendchar(pOut, k, ' ');
        col += k;
        z++;
        nVal--;
      }else if( c=='\r' && nVal==1 ){
        z++;
        nVal--;
      }else{
        char zCtrlPik[4];
        col++;
        zCtrlPik[0] = 0xe2;
        zCtrlPik[1] = 0x90;
        zCtrlPik[2] = 0x80+c;
        sqlite3_str_append(pOut, zCtrlPik, 3);
        z++;
        nVal--;
      }
    }else if( (0x80&c)==0 ){
      i++;
      col++;
    }else{
      int u = 0;
      int len = sqlite3_qrf_decode_utf8(&z[i], &u);
      i += len;
      col += sqlite3_qrf_wcwidth(u);
    }
  }
  sqlite3_str_append(pOut, (const char*)z, i);
}    

/*
** GCC does not define the offsetof() macro so we'll have to do it
** ourselves.
*/
#ifndef offsetof
# define offsetof(ST,M) ((size_t)((char*)&((ST*)0)->M - (char*)0))
#endif

/*
** Data for columnar layout, collected into a single object so
** that it can be more easily passed into subroutines.
*/
typedef struct qrfColData qrfColData;
struct qrfColData {
  Qrf *p;                  /* The QRF instance */
  int nCol;                /* Number of columns in the table */
  unsigned char bMultiRow; /* One or more cells will span multiple lines */
  unsigned char nMargin;   /* Width of column margins */
  sqlite3_int64 nRow;      /* Number of rows */
  sqlite3_int64 nAlloc;    /* Number of cells allocated */
  sqlite3_int64 n;         /* Number of cells.  nCol*nRow */
  char **az;               /* Content of all cells */
  int *aiWth;              /* Width of each cell */
  unsigned char *abNum;    /* True for each numeric cell */
  struct qrfPerCol {       /* Per-column data */
    char *z;                 /* Cache of text for current row */
    int w;                   /* Computed width of this column */
    int mxW;                 /* Maximum natural (unwrapped) width */
    unsigned char e;         /* Alignment */
    unsigned char fx;        /* Width is fixed */
    unsigned char bNum;      /* True if is numeric */
  } *a;                    /* One per column */
};

/*
** Output horizontally justified text into pOut.  The text is the
** first nVal bytes of zVal.  Include nWS bytes of whitespace, either
** split between both sides, or on the left, or on the right, depending
** on eAlign.
*/
static void qrfPrintAligned(
  sqlite3_str *pOut,       /* Append text here */
  struct qrfPerCol *pCol,  /* Information about the text to print */
  int nVal,                /* Use only the first nVal bytes of zVal[] */
  int nWS                 /* Whitespace for horizonal alignment */
){
  unsigned char eAlign = pCol->e & QRF_ALIGN_HMASK;
  if( eAlign==QRF_Auto && pCol->bNum ) eAlign = QRF_ALIGN_Right;
  if( eAlign==QRF_ALIGN_Center ){
    /* Center the text */
    sqlite3_str_appendchar(pOut, nWS/2, ' ');
    qrfAppendWithTabs(pOut, pCol->z, nVal);
    sqlite3_str_appendchar(pOut, nWS - nWS/2, ' ');
  }else if( eAlign==QRF_ALIGN_Right ){
    /* Right justify the text */
    sqlite3_str_appendchar(pOut, nWS, ' ');
    qrfAppendWithTabs(pOut, pCol->z, nVal);
  }else{
    /* Left justify the text */
    qrfAppendWithTabs(pOut, pCol->z, nVal);
    sqlite3_str_appendchar(pOut, nWS, ' ');
  }
}

/*
** Free all the memory allocates in the qrfColData object
*/
static void qrfColDataFree(qrfColData *p){
  sqlite3_int64 i;
  for(i=0; i<p->n; i++) sqlite3_free(p->az[i]);
  sqlite3_free(p->az);
  sqlite3_free(p->aiWth);
  sqlite3_free(p->abNum);
  sqlite3_free(p->a);
  memset(p, 0, sizeof(*p));
}

/*
** Allocate space for more cells in the qrfColData object.
** Return non-zero if a memory allocation fails.
*/
static int qrfColDataEnlarge(qrfColData *p){
  char **azData;
  int *aiWth;
  unsigned char *abNum;
  p->nAlloc = 2*p->nAlloc + 10*p->nCol;
  azData = sqlite3_realloc64(p->az, p->nAlloc*sizeof(char*));
  if( azData==0 ){
    qrfOom(p->p);
    qrfColDataFree(p);
    return 1;
  }
  p->az = azData;
  aiWth = sqlite3_realloc64(p->aiWth, p->nAlloc*sizeof(int));
  if( aiWth==0 ){
    qrfOom(p->p);
    qrfColDataFree(p);
    return 1;
  }
  p->aiWth = aiWth;
  abNum = sqlite3_realloc64(p->abNum, p->nAlloc);
  if( abNum==0 ){
    qrfOom(p->p);
    qrfColDataFree(p);
    return 1;
  }
  p->abNum = abNum;
  return 0;
}

/*
** Print a markdown or table-style row separator using ascii-art
*/
static void qrfRowSeparator(sqlite3_str *pOut, qrfColData *p, char cSep){
  int i;
  if( p->nCol>0 ){
    int useBorder = p->p->spec.bBorder!=QRF_No;
    if( useBorder ){
      sqlite3_str_append(pOut, &cSep, 1);
    }
    sqlite3_str_appendchar(pOut, p->a[0].w+p->nMargin, '-');
    for(i=1; i<p->nCol; i++){
      sqlite3_str_append(pOut, &cSep, 1);
      sqlite3_str_appendchar(pOut, p->a[i].w+p->nMargin, '-');
    }
    if( useBorder ){
      sqlite3_str_append(pOut, &cSep, 1);
    }
  }
  sqlite3_str_append(pOut, "\n", 1);
}

/*
** UTF8 box-drawing characters.  Imagine box lines like this:
**
**           1
**           |
**       4 --+-- 2
**           |
**           3
**
** Each box characters has between 2 and 4 of the lines leading from
** the center.  The characters are here identified by the numbers of
** their corresponding lines.
*/
#define BOX_24   "\342\224\200"  /* U+2500 --- */
#define BOX_13   "\342\224\202"  /* U+2502  |  */
#define BOX_23   "\342\224\214"  /* U+250c  ,- */
#define BOX_34   "\342\224\220"  /* U+2510 -,  */
#define BOX_12   "\342\224\224"  /* U+2514  '- */
#define BOX_14   "\342\224\230"  /* U+2518 -'  */
#define BOX_123  "\342\224\234"  /* U+251c  |- */
#define BOX_134  "\342\224\244"  /* U+2524 -|  */
#define BOX_234  "\342\224\254"  /* U+252c -,- */
#define BOX_124  "\342\224\264"  /* U+2534 -'- */
#define BOX_1234 "\342\224\274"  /* U+253c -|- */

/* Rounded corners: */
#define BOX_R12  "\342\225\260"  /* U+2570  '- */
#define BOX_R23  "\342\225\255"  /* U+256d  ,- */
#define BOX_R34  "\342\225\256"  /* U+256e -,  */
#define BOX_R14  "\342\225\257"  /* U+256f -'  */

/* Doubled horizontal lines: */
#define DBL_24   "\342\225\220"  /* U+2550 === */
#define DBL_123  "\342\225\236"  /* U+255e  |= */
#define DBL_134  "\342\225\241"  /* U+2561 =|  */
#define DBL_1234 "\342\225\252"  /* U+256a =|= */

/* Draw horizontal line N characters long using unicode box
** characters
*/
static void qrfBoxLine(sqlite3_str *pOut, int N, int bDbl){
  const char *azDash[2] = {
      BOX_24 BOX_24 BOX_24 BOX_24 BOX_24   BOX_24 BOX_24 BOX_24 BOX_24 BOX_24,
      DBL_24 DBL_24 DBL_24 DBL_24 DBL_24   DBL_24 DBL_24 DBL_24 DBL_24 DBL_24
  };/*  0       1      2     3      4        5      6      7      8      9   */
  const int nDash = 30;
  N *= 3;
  while( N>nDash ){
    sqlite3_str_append(pOut, azDash[bDbl], nDash);
    N -= nDash;
  }
  sqlite3_str_append(pOut, azDash[bDbl], N);
}

/*
** Draw a horizontal separator for a QRF_STYLE_Box table.
*/
static void qrfBoxSeparator(
  sqlite3_str *pOut,
  qrfColData *p,
  const char *zSep1,
  const char *zSep2,
  const char *zSep3,
  int bDbl
){
  int i;
  if( p->nCol>0 ){
    int useBorder = p->p->spec.bBorder!=QRF_No;
    if( useBorder ){
      sqlite3_str_appendall(pOut, zSep1);
    }
    qrfBoxLine(pOut, p->a[0].w+p->nMargin, bDbl);
    for(i=1; i<p->nCol; i++){
      sqlite3_str_appendall(pOut, zSep2);
      qrfBoxLine(pOut, p->a[i].w+p->nMargin, bDbl);
    }
    if( useBorder ){
      sqlite3_str_appendall(pOut, zSep3);
    }
  }
  sqlite3_str_append(pOut, "\n", 1);
}

/*
** Load into pData the default alignment for the body of a table.
*/
static void qrfLoadAlignment(qrfColData *pData, Qrf *p){
  sqlite3_int64 i;
  for(i=0; i<pData->nCol; i++){
    pData->a[i].e = p->spec.eDfltAlign;
    if( i<p->spec.nAlign ){
      unsigned char ax = p->spec.aAlign[i];
      if( (ax & QRF_ALIGN_HMASK)!=0 ){
        pData->a[i].e = (ax & QRF_ALIGN_HMASK) |
                            (pData->a[i].e & QRF_ALIGN_VMASK);
      }
    }else if( i<p->spec.nWidth ){
      if( p->spec.aWidth[i]<0 ){
         pData->a[i].e = QRF_ALIGN_Right |
                               (pData->a[i].e & QRF_ALIGN_VMASK);
      }
    }
  }
}

/*
** If the single column in pData->a[] with pData->n entries can be
** laid out as nCol columns with a 2-space gap between each such
** that all columns fit within nSW, then return a pointer to an array
** of integers which is the width of each column from left to right.
**
** If the layout is not possible, return a NULL pointer.
**
** Space to hold the returned array is from sqlite_malloc64().
*/
static int *qrfValidLayout(
  qrfColData *pData,   /* Collected query results */
  Qrf *p,              /* On which to report an OOM */
  int nCol,            /* Attempt this many columns */
  int nSW              /* Screen width */
){
  int i;        /* Loop counter */
  int nr;       /* Number of rows */
  int w = 0;    /* Width of the current column */
  int t;        /* Total width of all columns */
  int *aw;      /* Array of individual column widths */

  aw = sqlite3_malloc64( sizeof(int)*nCol );
  if( aw==0 ){
    qrfOom(p);
    return 0;
  }
  nr = (pData->n + nCol - 1)/nCol;
  for(i=0; i<pData->n; i++){
    if( (i%nr)==0 ){
      if( i>0 ) aw[i/nr-1] = w;
      w = pData->aiWth[i];
    }else if( pData->aiWth[i]>w ){
      w = pData->aiWth[i];
    }
  }
  aw[nCol-1] = w;
  for(t=i=0; i<nCol; i++) t += aw[i];
  t += 2*(nCol-1);
  if( t>nSW ){
    sqlite3_free(aw);
    return 0;
  }
  return aw;
}

/*
** The output is single-column and the bSplitColumn flag is set.
** Check to see if the single-column output can be split into multiple
** columns that appear side-by-side.  Adjust pData appropriately.
*/
static void qrfSplitColumn(qrfColData *pData, Qrf *p){
  int nCol = 1;
  int *aw = 0;
  char **az = 0;
  int *aiWth = 0;
  unsigned char *abNum = 0;
  int nColNext = 2;
  int w;
  struct qrfPerCol *a = 0;
  sqlite3_int64 nRow = 1;
  sqlite3_int64 i;
  while( 1/*exit-by-break*/ ){
    int *awNew = qrfValidLayout(pData, p, nColNext, p->spec.nScreenWidth);
    if( awNew==0 ) break;
    sqlite3_free(aw);
    aw = awNew;
    nCol = nColNext;
    nRow = (pData->n + nCol - 1)/nCol;
    if( nRow==1 ) break;
    nColNext++;
    while( (pData->n + nColNext - 1)/nColNext == nRow ) nColNext++;
  }
  if( nCol==1 ){
    sqlite3_free(aw);
    return;  /* Cannot do better than 1 column */
  }
  az = sqlite3_malloc64( nRow*nCol*sizeof(char*) );
  if( az==0 ){
    qrfOom(p);
    return;
  }
  aiWth = sqlite3_malloc64( nRow*nCol*sizeof(int) );
  if( aiWth==0 ){
    sqlite3_free(az);
    qrfOom(p);
    return;
  }
  a = sqlite3_malloc64( nCol*sizeof(struct qrfPerCol) );
  if( a==0 ){
    sqlite3_free(az);
    sqlite3_free(aiWth);
    qrfOom(p);
    return;
  }
  abNum = sqlite3_malloc64( nRow*nCol );
  if( abNum==0 ){
    sqlite3_free(az);
    sqlite3_free(aiWth);
    sqlite3_free(a);
    qrfOom(p);
    return;
  }
  for(i=0; i<pData->n; i++){
    sqlite3_int64 j = (i%nRow)*nCol + (i/nRow);
    az[j] = pData->az[i];
    abNum[j]= pData->abNum[i];
    pData->az[i] = 0;
    aiWth[j] = pData->aiWth[i];
  }
  while( i<nRow*nCol ){
    sqlite3_int64 j = (i%nRow)*nCol + (i/nRow);
    az[j] = sqlite3_mprintf("");
    if( az[j]==0 ) qrfOom(p);
    aiWth[j] = 0;
    abNum[j] = 0;
    i++;
  }
  for(i=0; i<nCol; i++){
    a[i].fx = a[i].mxW = a[i].w = aw[i];
    a[i].e = pData->a[0].e;
  }
  sqlite3_free(pData->az);
  sqlite3_free(pData->aiWth);
  sqlite3_free(pData->a);
  sqlite3_free(pData->abNum);
  sqlite3_free(aw);
  pData->az = az;
  pData->aiWth = aiWth;
  pData->a = a;
  pData->abNum = abNum;
  pData->nCol = nCol;
  pData->n = pData->nAlloc = nRow*nCol;
  for(i=w=0; i<nCol; i++) w += a[i].w;
  pData->nMargin = (p->spec.nScreenWidth - w)/(nCol - 1);
  if( pData->nMargin>5 ) pData->nMargin = 5;
}

/*
** Adjust the layout for the screen width restriction
*/
static void qrfRestrictScreenWidth(qrfColData *pData, Qrf *p){
  int sepW;             /* Width of all box separators and margins */
  int sumW;             /* Total width of data area over all columns */
  int targetW;          /* Desired total data area */
  int i;                /* Loop counters */
  int nCol;             /* Number of columns */

  pData->nMargin = 2;   /* Default to normal margins */
  if( p->spec.nScreenWidth==0 ) return;
  if( p->spec.eStyle==QRF_STYLE_Column ){
    sepW = pData->nCol*2 - 2;
  }else{
    sepW = pData->nCol*3 + 1;
    if( p->spec.bBorder==QRF_No ) sepW -= 2;
  }
  nCol = pData->nCol;
  for(i=sumW=0; i<nCol; i++) sumW += pData->a[i].w;
  if( p->spec.nScreenWidth >= sumW+sepW ) return;

  /* First thing to do is reduce the separation between columns */
  pData->nMargin = 0;
  if( p->spec.eStyle==QRF_STYLE_Column ){
    sepW = pData->nCol - 1;
  }else{
    sepW = pData->nCol + 1;
    if( p->spec.bBorder==QRF_No ) sepW -= 2;
  }
  targetW = p->spec.nScreenWidth - sepW;

#define MIN_SQUOZE    8
#define MIN_EX_SQUOZE 16
  /* Reduce the width of the widest eligible column.  A column is
  ** eligible for narrowing if:
  **
  **    *  It is not a fixed-width column  (a[0].fx is false)
  **    *  The current width is more than MIN_SQUOZE
  **    *  Either:
  **         +  The current width is more then MIN_EX_SQUOZE, or
  **         +  The current width is more than half the max width (a[].mxW)
  **
  ** Keep making reductions until either no more reductions are
  ** possible or until the size target is reached.
  */
  while( sumW > targetW ){
    int gain, w;
    int ix = -1;
    int mx = 0;
    for(i=0; i<nCol; i++){
      if( pData->a[i].fx==0
       && (w = pData->a[i].w)>mx
       && w>MIN_SQUOZE
       && (w>MIN_EX_SQUOZE || w*2>pData->a[i].mxW)
      ){
        ix = i;
        mx = w;
      }
    }
    if( ix<0 ) break;
    if( mx>=MIN_SQUOZE*2 ){
      gain = mx/2;
    }else{
      gain = mx - MIN_SQUOZE;
    }
    if( sumW - gain < targetW ){
      gain = sumW - targetW;
    }
    sumW -= gain;
    pData->a[ix].w -= gain;
    pData->bMultiRow = 1;
  }
}

/*
** Columnar modes require that the entire query be evaluated first, with
** results written into memory, so that we can compute appropriate column
** widths.
*/
static void qrfColumnar(Qrf *p){
  sqlite3_int64 i, j;                     /* Loop counters */
  const char *colSep = 0;                 /* Column separator text */
  const char *rowSep = 0;                 /* Row terminator text */
  const char *rowStart = 0;               /* Row start text */
  int szColSep, szRowSep, szRowStart;     /* Size in bytes of previous 3 */
  int rc;                                 /* Result code */
  int nColumn = p->nCol;                  /* Number of columns */
  int bWW;                                /* True to do word-wrap */
  sqlite3_str *pStr;                      /* Temporary rendering */
  qrfColData data;                        /* Columnar layout data */
  int bRTrim;                             /* Trim trailing space */

  rc = sqlite3_step(p->pStmt);
  if( rc!=SQLITE_ROW || nColumn==0 ){
    return;   /* No output */
  }

  /* Initialize the data container */
  memset(&data, 0, sizeof(data));
  data.nCol = p->nCol;
  data.p = p;
  data.a = sqlite3_malloc64( nColumn*sizeof(struct qrfPerCol) );
  if( data.a==0 ){
    qrfOom(p);
    return;
  }
  memset(data.a, 0, nColumn*sizeof(struct qrfPerCol) );
  if( qrfColDataEnlarge(&data) ) return;
  assert( data.az!=0 );

  /* Load the column header names and all cell content into data */
  if( p->spec.bTitles==QRF_Yes ){
    unsigned char saved_eText = p->spec.eText;
    p->spec.eText = p->spec.eTitle;
    memset(data.abNum, 0, nColumn);
    for(i=0; i<nColumn; i++){
      const char *z = (const char*)sqlite3_column_name(p->pStmt,i);
      int nNL = 0;
      int n, w;
      pStr = sqlite3_str_new(p->db);
      qrfEncodeText(p, pStr, z ? z : "");
      n = sqlite3_str_length(pStr);
      qrfStrErr(p, pStr);
      z = data.az[data.n] = sqlite3_str_finish(pStr);
      if( p->spec.nTitleLimit ){
        nNL = 0;
        data.aiWth[data.n] = w = qrfTitleLimit(data.az[data.n],
                                               p->spec.nTitleLimit );
      }else{
        data.aiWth[data.n] = w = qrfDisplayWidth(z, n, &nNL);
      }
      data.n++;
      if( w>data.a[i].mxW ) data.a[i].mxW = w;
      if( nNL ) data.bMultiRow = 1;
    }
    p->spec.eText = saved_eText;
    p->nRow++;
  }
  do{
    if( data.n+nColumn > data.nAlloc ){
      if( qrfColDataEnlarge(&data) ) return;
    }
    for(i=0; i<nColumn; i++){
      char *z;
      int nNL = 0;
      int n, w;
      int eType = sqlite3_column_type(p->pStmt,i);
      pStr = sqlite3_str_new(p->db);
      qrfRenderValue(p, pStr, i);
      n = sqlite3_str_length(pStr);
      qrfStrErr(p, pStr);
      z = data.az[data.n] = sqlite3_str_finish(pStr);
      data.abNum[data.n] = eType==SQLITE_INTEGER || eType==SQLITE_FLOAT;
      data.aiWth[data.n] = w = qrfDisplayWidth(z, n, &nNL);
      data.n++;
      if( w>data.a[i].mxW ) data.a[i].mxW = w;
      if( nNL ) data.bMultiRow = 1;
    }
    p->nRow++;
  }while( sqlite3_step(p->pStmt)==SQLITE_ROW && p->iErr==SQLITE_OK );
  if( p->iErr ){
    qrfColDataFree(&data);
    return;
  }

  /* Compute the width and alignment of every column */
  if( p->spec.bTitles==QRF_No ){
    qrfLoadAlignment(&data, p);
  }else{
    unsigned char e;
    if( p->spec.eTitleAlign==QRF_Auto ){
      e = QRF_ALIGN_Center;
    }else{
      e = p->spec.eTitleAlign;
    }
    for(i=0; i<nColumn; i++) data.a[i].e = e;
  }

  for(i=0; i<nColumn; i++){
    int w = 0;
    if( i<p->spec.nWidth ){
      w = p->spec.aWidth[i];
      if( w==(-32768) ){
        w = 0;
        if( p->spec.nAlign>i && (p->spec.aAlign[i] & QRF_ALIGN_HMASK)==0 ){
          data.a[i].e |= QRF_ALIGN_Right;
        }
      }else if( w<0 ){
        w = -w;
        if( p->spec.nAlign>i && (p->spec.aAlign[i] & QRF_ALIGN_HMASK)==0 ){
          data.a[i].e |= QRF_ALIGN_Right;
        }
      }
      if( w ) data.a[i].fx = 1;
    }
    if( w==0 ){
      w = data.a[i].mxW;
      if( p->spec.nWrap>0 && w>p->spec.nWrap ){
        w = p->spec.nWrap;
        data.bMultiRow = 1;
      }
    }else if( (data.bMultiRow==0 || w==1) && data.a[i].mxW>w ){
      data.bMultiRow = 1;
      if( w==1 ){
        /* If aiWth[j] is 2 or more, then there might be a double-wide
        ** character somewhere.  So make the column width at least 2. */
        w = 2;
      }
    }
    data.a[i].w = w;
  }

  if( nColumn==1
   && data.n>1
   && p->spec.bSplitColumn==QRF_Yes
   && p->spec.eStyle==QRF_STYLE_Column
   && p->spec.bTitles==QRF_No
   && p->spec.nScreenWidth>data.a[0].w+3
  ){
    /* Attempt to convert single-column tables into multi-column by
    ** verticle wrapping, if the screen is wide enough and if the
    ** bSplitColumn flag is set. */
    qrfSplitColumn(&data, p);
    nColumn = data.nCol;
  }else{
    /* Adjust the column widths due to screen width restrictions */
    qrfRestrictScreenWidth(&data, p);
  }

  /* Draw the line across the top of the table.  Also initialize
  ** the row boundary and column separator texts. */
  switch( p->spec.eStyle ){
    case QRF_STYLE_Box:
      if( data.nMargin ){
        rowStart = BOX_13 " ";
        colSep = " " BOX_13 " ";
        rowSep = " " BOX_13 "\n";
      }else{
        rowStart = BOX_13;
        colSep = BOX_13;
        rowSep = BOX_13 "\n";
      }
      if( p->spec.bBorder==QRF_No){
        rowStart += 3;
        rowSep = "\n";
      }else{
        qrfBoxSeparator(p->pOut, &data, BOX_R23, BOX_234, BOX_R34, 0);
      }
      break;
    case QRF_STYLE_Table:
      if( data.nMargin ){
        rowStart = "| ";
        colSep = " | ";
        rowSep = " |\n";
      }else{
        rowStart = "|";
        colSep = "|";
        rowSep = "|\n";
      }
      if( p->spec.bBorder==QRF_No ){
        rowStart += 1;
        rowSep = "\n";
      }else{
        qrfRowSeparator(p->pOut, &data, '+');
      }
      break;
    case QRF_STYLE_Column: {
      static const char zSpace[] = "     ";
      rowStart = "";
      if( data.nMargin<2 ){
        colSep = " ";
      }else if( data.nMargin<=5 ){
        colSep = &zSpace[5-data.nMargin];
      }else{
        colSep = zSpace;
      }
      rowSep = "\n";
      break;
    }
    default:  /*case QRF_STYLE_Markdown:*/
      if( data.nMargin ){
        rowStart = "| ";
        colSep = " | ";
        rowSep = " |\n";
      }else{
        rowStart = "|";
        colSep = "|";
        rowSep = "|\n";
      }
      break;
  }
  szRowStart = (int)strlen(rowStart);
  szRowSep = (int)strlen(rowSep);
  szColSep = (int)strlen(colSep);

  bWW = (p->spec.bWordWrap==QRF_Yes && data.bMultiRow);
  if( p->spec.eStyle==QRF_STYLE_Column
   || (p->spec.bBorder==QRF_No
       && (p->spec.eStyle==QRF_STYLE_Box || p->spec.eStyle==QRF_STYLE_Table)
      )
  ){
    bRTrim = 1;
  }else{
    bRTrim = 0;
  }
  for(i=0; i<data.n && sqlite3_str_errcode(p->pOut)==SQLITE_OK; i+=nColumn){
    int bMore;
    int nRow = 0;

    /* Draw a single row of the table.  This might be the title line
    ** (if there is a title line) or a row in the body of the table.
    ** The column number will be j.  The row number is i/nColumn.
    */
    for(j=0; j<nColumn; j++){
      data.a[j].z = data.az[i+j];
      if( data.a[j].z==0 ) data.a[j].z = "";
      data.a[j].bNum = data.abNum[i+j];
    }
    do{
      sqlite3_str_append(p->pOut, rowStart, szRowStart);
      bMore = 0;
      for(j=0; j<nColumn; j++){
        int nThis = 0;
        int nWide = 0;
        int iNext = 0;
        int nWS;
        qrfWrapLine(data.a[j].z, data.a[j].w, bWW, &nThis, &nWide, &iNext);
        nWS = data.a[j].w - nWide;
        qrfPrintAligned(p->pOut, &data.a[j], nThis, nWS);
        data.a[j].z += iNext;
        if( data.a[j].z[0]!=0 ){
          bMore = 1;
        }
        if( j<nColumn-1 ){
          sqlite3_str_append(p->pOut, colSep, szColSep);
        }else{
          if( bRTrim ) qrfRTrim(p->pOut);
          sqlite3_str_append(p->pOut, rowSep, szRowSep);
        }
      }
    }while( bMore && ++nRow < p->mxHeight );
    if( bMore ){
      /* This row was terminated by nLineLimit.  Show ellipsis. */
      sqlite3_str_append(p->pOut, rowStart, szRowStart);
      for(j=0; j<nColumn; j++){
        if( data.a[j].z[0]==0 ){
          sqlite3_str_appendchar(p->pOut, data.a[j].w, ' ');
        }else{
          int nE = 3;
          if( nE>data.a[j].w ) nE = data.a[j].w;
          data.a[j].z = "...";
          qrfPrintAligned(p->pOut, &data.a[j], nE, data.a[j].w-nE);
        }
        if( j<nColumn-1 ){
          sqlite3_str_append(p->pOut, colSep, szColSep);
        }else{
          if( bRTrim ) qrfRTrim(p->pOut);
          sqlite3_str_append(p->pOut, rowSep, szRowSep);
        }
      }
    }

    /* Draw either (1) the separator between the title line and the body
    ** of the table, or (2) separators between individual rows of the table
    ** body.  isTitleDataSeparator will be true if we are doing (1).
    */
    if( (i==0 || data.bMultiRow) && i+nColumn<data.n ){
      int isTitleDataSeparator = (i==0 && p->spec.bTitles==QRF_Yes);
      if( isTitleDataSeparator ){
        qrfLoadAlignment(&data, p);
      }
      switch( p->spec.eStyle ){
        case QRF_STYLE_Table: {
          if( isTitleDataSeparator || data.bMultiRow ){
            qrfRowSeparator(p->pOut, &data, '+');
          }
          break;
        }
        case QRF_STYLE_Box: {
          if( isTitleDataSeparator ){
            qrfBoxSeparator(p->pOut, &data, DBL_123, DBL_1234, DBL_134, 1);
          }else if( data.bMultiRow ){
            qrfBoxSeparator(p->pOut, &data, BOX_123, BOX_1234, BOX_134, 0);
          }
          break;
        }
        case QRF_STYLE_Markdown: {
          if( isTitleDataSeparator ){
            qrfRowSeparator(p->pOut, &data, '|');
          }
          break;
        }
        case QRF_STYLE_Column: {
          if( isTitleDataSeparator ){
            for(j=0; j<nColumn; j++){
              sqlite3_str_appendchar(p->pOut, data.a[j].w, '-');
              if( j<nColumn-1 ){
                sqlite3_str_append(p->pOut, colSep, szColSep);
              }else{
                qrfRTrim(p->pOut);
                sqlite3_str_append(p->pOut, rowSep, szRowSep);
              }
            }
          }else if( data.bMultiRow ){
            qrfRTrim(p->pOut);
            sqlite3_str_append(p->pOut, "\n", 1);
          }
          break;
        }
      }
    }
  }

  /* Draw the line across the bottom of the table */
  if( p->spec.bBorder!=QRF_No ){
    switch( p->spec.eStyle ){
      case QRF_STYLE_Box:
        qrfBoxSeparator(p->pOut, &data, BOX_R12, BOX_124, BOX_R14, 0);
        break;
      case QRF_STYLE_Table:
        qrfRowSeparator(p->pOut, &data, '+');
        break;
    }
  }
  qrfWrite(p);

  qrfColDataFree(&data);
  return;
}

/*
** Parameter azArray points to a zero-terminated array of strings. zStr
** points to a single nul-terminated string. Return non-zero if zStr
** is equal, according to strcmp(), to any of the strings in the array.
** Otherwise, return zero.
*/
static int qrfStringInArray(const char *zStr, const char **azArray){
  int i;
  if( zStr==0 ) return 0;
  for(i=0; azArray[i]; i++){
    if( 0==strcmp(zStr, azArray[i]) ) return 1;
  }
  return 0;
}

/*
** Print out an EXPLAIN with indentation.  This is a two-pass algorithm.
**
** On the first pass, we compute aiIndent[iOp] which is the amount of
** indentation to apply to the iOp-th opcode.  The output actually occurs
** on the second pass.
**
** The indenting rules are:
**
**     * For each "Next", "Prev", "VNext" or "VPrev" instruction, indent
**       all opcodes that occur between the p2 jump destination and the opcode
**       itself by 2 spaces.
**
**     * Do the previous for "Return" instructions for when P2 is positive.
**       See tag-20220407a in wherecode.c and vdbe.c.
**
**     * For each "Goto", if the jump destination is earlier in the program
**       and ends on one of:
**          Yield  SeekGt  SeekLt  RowSetRead  Rewind
**       or if the P1 parameter is one instead of zero,
**       then indent all opcodes between the earlier instruction
**       and "Goto" by 2 spaces.
*/
static void qrfExplain(Qrf *p){
  int *abYield = 0;     /* abYield[iOp] is rue if opcode iOp is an OP_Yield */
  int *aiIndent = 0;    /* Indent the iOp-th opcode by aiIndent[iOp] */
  i64 nAlloc = 0;       /* Allocated size of aiIndent[], abYield */
  int nIndent = 0;      /* Number of entries in aiIndent[] */
  int iOp;              /* Opcode number */
  int i;                /* Column loop counter */

  const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext",
                           "Return", 0 };
  const char *azYield[] = { "Yield", "SeekLT", "SeekGT", "RowSetRead",
                            "Rewind", 0 };
  const char *azGoto[] = { "Goto", 0 };

  /* The caller guarantees that the leftmost 4 columns of the statement
  ** passed to this function are equivalent to the leftmost 4 columns
  ** of EXPLAIN statement output. In practice the statement may be
  ** an EXPLAIN, or it may be a query on the bytecode() virtual table.  */
  assert( sqlite3_column_count(p->pStmt)>=4 );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(p->pStmt, 0), "addr" ) );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(p->pStmt, 1), "opcode" ) );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(p->pStmt, 2), "p1" ) );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(p->pStmt, 3), "p2" ) );

  for(iOp=0; SQLITE_ROW==sqlite3_step(p->pStmt) && !p->iErr; iOp++){
    int iAddr = sqlite3_column_int(p->pStmt, 0);
    const char *zOp = (const char*)sqlite3_column_text(p->pStmt, 1);
    int p1 = sqlite3_column_int(p->pStmt, 2);
    int p2 = sqlite3_column_int(p->pStmt, 3);

    /* Assuming that p2 is an instruction address, set variable p2op to the
    ** index of that instruction in the aiIndent[] array. p2 and p2op may be
    ** different if the current instruction is part of a sub-program generated
    ** by an SQL trigger or foreign key.  */
    int p2op = (p2 + (iOp-iAddr));

    /* Grow the aiIndent array as required */
    if( iOp>=nAlloc ){
      nAlloc += 100;
      aiIndent = (int*)sqlite3_realloc64(aiIndent, nAlloc*sizeof(int));
      abYield = (int*)sqlite3_realloc64(abYield, nAlloc*sizeof(int));
      if( aiIndent==0 || abYield==0 ){
        qrfOom(p);
        sqlite3_free(aiIndent);
        sqlite3_free(abYield);
        return;
      }
    }

    abYield[iOp] = qrfStringInArray(zOp, azYield);
    aiIndent[iOp] = 0;
    nIndent = iOp+1;
    if( qrfStringInArray(zOp, azNext) && p2op>0 ){
      for(i=p2op; i<iOp; i++) aiIndent[i] += 2;
    }
    if( qrfStringInArray(zOp, azGoto) && p2op<iOp && (abYield[p2op] || p1) ){
      for(i=p2op; i<iOp; i++) aiIndent[i] += 2;
    }
  }
  sqlite3_free(abYield);

  /* Second pass.  Actually generate output */
  sqlite3_reset(p->pStmt);
  if( p->iErr==SQLITE_OK ){
    static const int aExplainWidth[] = {4,       13, 4, 4, 4, 13, 2, 13};
    static const int aExplainMap[] =   {0,       1,  2, 3, 4, 5,  6, 7 };
    static const int aScanExpWidth[] = {4,15, 6, 13, 4, 4, 4, 13, 2, 13};
    static const int aScanExpMap[] =   {0, 9, 8, 1,  2, 3, 4, 5,  6, 7 };
    const int *aWidth = aExplainWidth;
    const int *aMap = aExplainMap;
    int nWidth = sizeof(aExplainWidth)/sizeof(int);
    int iIndent = 1;
    int nArg = p->nCol;
    if( p->spec.eStyle==QRF_STYLE_StatsVm ){
      aWidth = aScanExpWidth;
      aMap = aScanExpMap;
      nWidth = sizeof(aScanExpWidth)/sizeof(int);
      iIndent = 3;
    }
    if( nArg>nWidth ) nArg = nWidth;

    for(iOp=0; sqlite3_step(p->pStmt)==SQLITE_ROW && !p->iErr; iOp++){
      /* If this is the first row seen, print out the headers */
      if( iOp==0 ){
        for(i=0; i<nArg; i++){
          const char *zCol = sqlite3_column_name(p->pStmt, aMap[i]);
          qrfWidthPrint(p,p->pOut, aWidth[i], zCol);
          if( i==nArg-1 ){
            sqlite3_str_append(p->pOut, "\n", 1);
          }else{
            sqlite3_str_append(p->pOut, "  ", 2);
          }
        }
        for(i=0; i<nArg; i++){
          sqlite3_str_appendf(p->pOut, "%.*c", aWidth[i], '-');
          if( i==nArg-1 ){
            sqlite3_str_append(p->pOut, "\n", 1);
          }else{
            sqlite3_str_append(p->pOut, "  ", 2);
          }
        }
      }
  
      for(i=0; i<nArg; i++){
        const char *zSep = "  ";
        int w = aWidth[i];
        const char *zVal = (const char*)sqlite3_column_text(p->pStmt, aMap[i]);
        int len;
        if( i==nArg-1 ) w = 0;
        if( zVal==0 ) zVal = "";
        len = (int)sqlite3_qrf_wcswidth(zVal);
        if( len>w ){
          w = len;
          zSep = " ";
        }
        if( i==iIndent && aiIndent && iOp<nIndent ){
          sqlite3_str_appendchar(p->pOut, aiIndent[iOp], ' ');
        }
        qrfWidthPrint(p, p->pOut, w, zVal);
        if( i==nArg-1 ){
          sqlite3_str_append(p->pOut, "\n", 1);
        }else{
          sqlite3_str_appendall(p->pOut, zSep);
        }
      }
      p->nRow++;
    }
    qrfWrite(p);
  }
  sqlite3_free(aiIndent);
}

/*
** Do a "scanstatus vm" style EXPLAIN listing on p->pStmt.
**
** p->pStmt is probably not an EXPLAIN query.  Instead, construct a
** new query that is a bytecode() rendering of p->pStmt with extra
** columns for the "scanstatus vm" outputs, and run the results of
** that new query through the normal EXPLAIN formatting.
*/
static void qrfScanStatusVm(Qrf *p){
  sqlite3_stmt *pOrigStmt = p->pStmt;
  sqlite3_stmt *pExplain;
  int rc;
  static const char *zSql =
      "  SELECT addr, opcode, p1, p2, p3, p4, p5, comment, nexec,"
      "   format('% 6s (%.2f%%)',"
      "      CASE WHEN ncycle<100_000 THEN ncycle || ' '"
      "         WHEN ncycle<100_000_000 THEN (ncycle/1_000) || 'K'"
      "         WHEN ncycle<100_000_000_000 THEN (ncycle/1_000_000) || 'M'"
      "         ELSE (ncycle/1000_000_000) || 'G' END,"
      "       ncycle*100.0/(sum(ncycle) OVER ())"
      "   )  AS cycles"
      "   FROM bytecode(?1)";
  rc = sqlite3_prepare_v2(p->db, zSql, -1, &pExplain, 0);
  if( rc ){
    qrfError(p, rc, "%s", sqlite3_errmsg(p->db));
    sqlite3_finalize(pExplain);
    return;
  }
  sqlite3_bind_pointer(pExplain, 1, pOrigStmt, "stmt-pointer", 0);
  p->pStmt = pExplain;
  p->nCol = 10;
  qrfExplain(p);
  sqlite3_finalize(pExplain);
  p->pStmt = pOrigStmt;
}

/*
** Attempt to determine if identifier zName needs to be quoted, either
** because it contains non-alphanumeric characters, or because it is an
** SQLite keyword.  Be conservative in this estimate:  When in doubt assume
** that quoting is required.
**
** Return 1 if quoting is required.  Return 0 if no quoting is required.
*/

static int qrf_need_quote(const char *zName){
  int i;
  const unsigned char *z = (const unsigned char*)zName;
  if( z==0 ) return 1;
  if( !qrfAlpha(z[0]) ) return 1;
  for(i=0; z[i]; i++){
    if( !qrfAlnum(z[i]) ) return 1;
  }
  return sqlite3_keyword_check(zName, i)!=0;
}

/*
** Helper function for QRF_STYLE_Json and QRF_STYLE_JObject.
** The initial "{" for a JSON object that will contain row content
** has been output.  Now output all the content.
*/
static void qrfOneJsonRow(Qrf *p){
  int i, nItem; 
  for(nItem=i=0; i<p->nCol; i++){
    const char *zCName;
    zCName = sqlite3_column_name(p->pStmt, i);
    if( nItem>0 ) sqlite3_str_append(p->pOut, ",", 1);
    nItem++;
    qrfEncodeText(p, p->pOut, zCName);
    sqlite3_str_append(p->pOut, ":", 1);
    qrfRenderValue(p, p->pOut, i);
  }
  qrfWrite(p);
}

/*
** Render a single row of output for non-columnar styles - any
** style that lets us render row by row as the content is received
** from the query.
*/
static void qrfOneSimpleRow(Qrf *p){
  int i;
  switch( p->spec.eStyle ){
    case QRF_STYLE_Off:
    case QRF_STYLE_Count: {
      /* No-op */
      break;
    }
    case QRF_STYLE_Json: {
      if( p->nRow==0 ){
        sqlite3_str_append(p->pOut, "[{", 2);
      }else{
        sqlite3_str_append(p->pOut, "},\n{", 4);
      }
      qrfOneJsonRow(p);
      break;
    }
    case QRF_STYLE_JObject: {
      if( p->nRow==0 ){
        sqlite3_str_append(p->pOut, "{", 1);
      }else{
        sqlite3_str_append(p->pOut, "}\n{", 3);
      }
      qrfOneJsonRow(p);
      break;
    }
    case QRF_STYLE_Html: {
      if( p->nRow==0 && p->spec.bTitles==QRF_Yes ){
        sqlite3_str_append(p->pOut, "<TR>", 4);
        for(i=0; i<p->nCol; i++){
          const char *zCName = sqlite3_column_name(p->pStmt, i);
          sqlite3_str_append(p->pOut, "\n<TH>", 5);
          qrfEncodeText(p, p->pOut, zCName);
        }
        sqlite3_str_append(p->pOut, "\n</TR>\n", 7);
      }
      sqlite3_str_append(p->pOut, "<TR>", 4);
      for(i=0; i<p->nCol; i++){
        sqlite3_str_append(p->pOut, "\n<TD>", 5);
        qrfRenderValue(p, p->pOut, i);
      }
      sqlite3_str_append(p->pOut, "\n</TR>\n", 7);
      qrfWrite(p);
      break;
    }
    case QRF_STYLE_Insert: {
      unsigned int mxIns = p->spec.nMultiInsert;
      int szStart = sqlite3_str_length(p->pOut);
      if( p->u.nIns==0 || p->u.nIns>=mxIns ){
        if( p->u.nIns ){
          sqlite3_str_append(p->pOut, ";\n", 2);
          p->u.nIns = 0;
        }
        if( qrf_need_quote(p->spec.zTableName) ){
          sqlite3_str_appendf(p->pOut,"INSERT INTO \"%w\"",p->spec.zTableName);
        }else{
          sqlite3_str_appendf(p->pOut,"INSERT INTO %s",p->spec.zTableName);
        }
        if( p->spec.bTitles==QRF_Yes ){
          for(i=0; i<p->nCol; i++){
            const char *zCName = sqlite3_column_name(p->pStmt, i);
            if( qrf_need_quote(zCName) ){
              sqlite3_str_appendf(p->pOut, "%c\"%w\"",
                                  i==0 ? '(' : ',', zCName);
            }else{
              sqlite3_str_appendf(p->pOut, "%c%s",
                                  i==0 ? '(' : ',', zCName);
            }
          }
          sqlite3_str_append(p->pOut, ")", 1);
        }
        sqlite3_str_append(p->pOut," VALUES(", 8);
      }else{
        sqlite3_str_append(p->pOut,",\n  (", 5);
      }
      for(i=0; i<p->nCol; i++){
        if( i>0 ) sqlite3_str_append(p->pOut, ",", 1);
        qrfRenderValue(p, p->pOut, i);
      }
      p->u.nIns += sqlite3_str_length(p->pOut) + 2 - szStart;
      if( p->u.nIns>=mxIns ){
        sqlite3_str_append(p->pOut, ");\n", 3);
        p->u.nIns = 0;
      }else{
        sqlite3_str_append(p->pOut, ")", 1);
      }
      qrfWrite(p);
      break;
    }
    case QRF_STYLE_Line: {
      sqlite3_str *pVal;
      int mxW;
      int bWW;
      int nSep;
      if( p->u.sLine.azCol==0 ){
        p->u.sLine.azCol = sqlite3_malloc64( p->nCol*sizeof(char*) );
        if( p->u.sLine.azCol==0 ){
          qrfOom(p);
          break;
        }
        p->u.sLine.mxColWth = 0;
        for(i=0; i<p->nCol; i++){
          int sz;
          const char *zCName = sqlite3_column_name(p->pStmt, i);
          if( zCName==0 ) zCName = "unknown";
          p->u.sLine.azCol[i] = sqlite3_mprintf("%s", zCName);
          if( p->spec.nTitleLimit>0 ){
            (void)qrfTitleLimit(p->u.sLine.azCol[i], p->spec.nTitleLimit);
          }
          sz = (int)sqlite3_qrf_wcswidth(p->u.sLine.azCol[i]);
          if( sz > p->u.sLine.mxColWth ) p->u.sLine.mxColWth = sz;
        }
      }
      if( p->nRow ) sqlite3_str_append(p->pOut, "\n", 1);
      pVal = sqlite3_str_new(p->db);
      nSep = (int)strlen(p->spec.zColumnSep);
      mxW = p->mxWidth - (nSep + p->u.sLine.mxColWth);
      bWW = p->spec.bWordWrap==QRF_Yes;
      for(i=0; i<p->nCol; i++){
        const char *zVal;
        int cnt = 0;
        qrfWidthPrint(p, p->pOut, -p->u.sLine.mxColWth, p->u.sLine.azCol[i]);
        sqlite3_str_append(p->pOut, p->spec.zColumnSep, nSep);
        qrfRenderValue(p, pVal, i);
        zVal = sqlite3_str_value(pVal);
        if( zVal==0 ) zVal = "";
        do{
          int nThis, nWide, iNext;
          qrfWrapLine(zVal, mxW, bWW, &nThis, &nWide, &iNext);
          if( cnt ){
            sqlite3_str_appendchar(p->pOut,p->u.sLine.mxColWth+nSep,' ');
          }
          cnt++;
          if( cnt>p->mxHeight ){
            zVal = "...";
            nThis = iNext = 3;
          }
          sqlite3_str_append(p->pOut, zVal, nThis);
          sqlite3_str_append(p->pOut, "\n", 1);
          zVal += iNext;
        }while( zVal[0] );
        sqlite3_str_reset(pVal);
      }
      qrfStrErr(p, pVal);
      sqlite3_free(sqlite3_str_finish(pVal));
      qrfWrite(p);
      break;
    }
    case QRF_STYLE_Eqp: {
      const char *zEqpLine = (const char*)sqlite3_column_text(p->pStmt,3);
      int iEqpId = sqlite3_column_int(p->pStmt, 0);
      int iParentId = sqlite3_column_int(p->pStmt, 1);
      if( zEqpLine==0 ) zEqpLine = "";
      if( zEqpLine[0]=='-' ) qrfEqpRender(p, 0);
      qrfEqpAppend(p, iEqpId, iParentId, zEqpLine);
      break;
    }
    default: {  /* QRF_STYLE_List */
      if( p->nRow==0 && p->spec.bTitles==QRF_Yes ){
        int saved_eText = p->spec.eText;
        p->spec.eText = p->spec.eTitle;
        for(i=0; i<p->nCol; i++){
          const char *zCName = sqlite3_column_name(p->pStmt, i);
          if( i>0 ) sqlite3_str_appendall(p->pOut, p->spec.zColumnSep);
          qrfEncodeText(p, p->pOut, zCName);
        }
        sqlite3_str_appendall(p->pOut, p->spec.zRowSep);
        qrfWrite(p);
        p->spec.eText = saved_eText;
      }
      for(i=0; i<p->nCol; i++){
        if( i>0 ) sqlite3_str_appendall(p->pOut, p->spec.zColumnSep);
        qrfRenderValue(p, p->pOut, i);
      }
      sqlite3_str_appendall(p->pOut, p->spec.zRowSep);
      qrfWrite(p);
      break;
    }
  }
  p->nRow++;
}

/*
** Initialize the internal Qrf object.
*/
static void qrfInitialize(
  Qrf *p,                        /* State object to be initialized */
  sqlite3_stmt *pStmt,           /* Query whose output to be formatted */
  const sqlite3_qrf_spec *pSpec, /* Format specification */
  char **pzErr                   /* Write errors here */
){
  size_t sz;                     /* Size of pSpec[], based on pSpec->iVersion */
  memset(p, 0, sizeof(*p));
  p->pzErr = pzErr;
  if( pSpec->iVersion>1 ){
    qrfError(p, SQLITE_ERROR,
       "unusable sqlite3_qrf_spec.iVersion (%d)",
       pSpec->iVersion);
    return;
  }
  p->pStmt = pStmt;
  p->db = sqlite3_db_handle(pStmt);
  p->pOut = sqlite3_str_new(p->db);
  if( p->pOut==0 ){
    qrfOom(p);
    return;
  }
  p->iErr = SQLITE_OK;
  p->nCol = sqlite3_column_count(p->pStmt);
  p->nRow = 0;
  sz = sizeof(sqlite3_qrf_spec);
  memcpy(&p->spec, pSpec, sz);
  if( p->spec.zNull==0 ) p->spec.zNull = "";
  p->mxWidth = p->spec.nScreenWidth;
  if( p->mxWidth<=0 ) p->mxWidth = QRF_MAX_WIDTH;
  p->mxHeight = p->spec.nLineLimit;
  if( p->mxHeight<=0 ) p->mxHeight = 2147483647;
  if( p->spec.eStyle>QRF_STYLE_Table ) p->spec.eStyle = QRF_Auto;
  if( p->spec.eEsc>QRF_ESC_Symbol ) p->spec.eEsc = QRF_Auto;
  if( p->spec.eText>QRF_TEXT_Relaxed ) p->spec.eText = QRF_Auto;
  if( p->spec.eTitle>QRF_TEXT_Relaxed ) p->spec.eTitle = QRF_Auto;
  if( p->spec.eBlob>QRF_BLOB_Size ) p->spec.eBlob = QRF_Auto;
qrf_reinit:
  switch( p->spec.eStyle ){
    case QRF_Auto: {
      switch( sqlite3_stmt_isexplain(pStmt) ){
        case 0:  p->spec.eStyle = QRF_STYLE_Box;      break;
        case 1:  p->spec.eStyle = QRF_STYLE_Explain;  break;
        default: p->spec.eStyle = QRF_STYLE_Eqp;      break;
      }
      goto qrf_reinit;
    }
    case QRF_STYLE_List: {
      if( p->spec.zColumnSep==0 ) p->spec.zColumnSep = "|";
      if( p->spec.zRowSep==0 ) p->spec.zRowSep = "\n";
      break;
    }
    case QRF_STYLE_JObject:
    case QRF_STYLE_Json: {
      p->spec.eText = QRF_TEXT_Json;
      p->spec.zNull = "null";
      break;
    }
    case QRF_STYLE_Html: {
      p->spec.eText = QRF_TEXT_Html;
      p->spec.zNull = "null";
      break;
    }
    case QRF_STYLE_Insert: {
      p->spec.eText = QRF_TEXT_Sql;
      p->spec.zNull = "NULL";
      if( p->spec.zTableName==0 || p->spec.zTableName[0]==0 ){
        p->spec.zTableName = "tab";
      }
      p->u.nIns = 0;
      break;
    }
    case QRF_STYLE_Line: {
      if( p->spec.zColumnSep==0 ){
        p->spec.zColumnSep = ": ";
      }
      break;
    }
    case QRF_STYLE_Csv: {
      p->spec.eStyle = QRF_STYLE_List;
      p->spec.eText = QRF_TEXT_Csv;
      p->spec.zColumnSep = ",";
      p->spec.zRowSep = "\r\n";
      p->spec.zNull = "";
      break;
    }
    case QRF_STYLE_Quote: {
      p->spec.eText = QRF_TEXT_Sql;
      p->spec.zNull = "NULL";
      p->spec.zColumnSep = ",";
      p->spec.zRowSep = "\n";
      break;
    }
    case QRF_STYLE_Eqp: {
      int expMode = sqlite3_stmt_isexplain(p->pStmt);
      if( expMode!=2 ){
        sqlite3_stmt_explain(p->pStmt, 2);
        p->expMode = expMode+1;
      }
      break;
    }
    case QRF_STYLE_Explain: {
      int expMode = sqlite3_stmt_isexplain(p->pStmt);
      if( expMode!=1 ){
        sqlite3_stmt_explain(p->pStmt, 1);
        p->expMode = expMode+1;
      }
      break;
    }
  }
  if( p->spec.eEsc==QRF_Auto ){
    p->spec.eEsc = QRF_ESC_Ascii;
  }
  if( p->spec.eText==QRF_Auto ){
    p->spec.eText = QRF_TEXT_Plain;
  }
  if( p->spec.eTitle==QRF_Auto ){
    switch( p->spec.eStyle ){
      case QRF_STYLE_Box:
      case QRF_STYLE_Column:
      case QRF_STYLE_Table:
        p->spec.eTitle = QRF_TEXT_Plain;
        break;
      default:
        p->spec.eTitle = p->spec.eText;
        break;
    }
  }
  if( p->spec.eBlob==QRF_Auto ){
    switch( p->spec.eText ){
      case QRF_TEXT_Sql:  p->spec.eBlob = QRF_BLOB_Sql;  break;
      case QRF_TEXT_Csv:  p->spec.eBlob = QRF_BLOB_Tcl;  break;
      case QRF_TEXT_Tcl:  p->spec.eBlob = QRF_BLOB_Tcl;  break;
      case QRF_TEXT_Json: p->spec.eBlob = QRF_BLOB_Json; break;
      default:            p->spec.eBlob = QRF_BLOB_Text; break;
    }
  }
  if( p->spec.bTitles==QRF_Auto ){
    switch( p->spec.eStyle ){
      case QRF_STYLE_Box:
      case QRF_STYLE_Csv:
      case QRF_STYLE_Column:
      case QRF_STYLE_Table:
      case QRF_STYLE_Markdown:
        p->spec.bTitles = QRF_Yes;
        break;
      default:
        p->spec.bTitles = QRF_No;
        break;
    }
  }
  if( p->spec.bWordWrap==QRF_Auto ){
    p->spec.bWordWrap = QRF_Yes;
  }
  if( p->spec.bTextJsonb==QRF_Auto ){
    p->spec.bTextJsonb = QRF_No;
  }
  if( p->spec.zColumnSep==0 ) p->spec.zColumnSep = ",";
  if( p->spec.zRowSep==0 ) p->spec.zRowSep = "\n";
}

/*
** Finish rendering the results
*/
static void qrfFinalize(Qrf *p){
  switch( p->spec.eStyle ){
    case QRF_STYLE_Count: {
      sqlite3_str_appendf(p->pOut, "%lld\n", p->nRow);
      break;
    }
    case QRF_STYLE_Json: {
      if( p->nRow>0 ){
        sqlite3_str_append(p->pOut, "}]\n", 3);
      }
      break;
    }
    case QRF_STYLE_JObject: {
      if( p->nRow>0 ){
        sqlite3_str_append(p->pOut, "}\n", 2);
      }
      break;
    }
    case QRF_STYLE_Insert: {
      if( p->u.nIns ){
        sqlite3_str_append(p->pOut, ";\n", 2);
      }
      break;
    }
    case QRF_STYLE_Line: {
      if( p->u.sLine.azCol ){
        int i;
        for(i=0; i<p->nCol; i++) sqlite3_free(p->u.sLine.azCol[i]);
        sqlite3_free(p->u.sLine.azCol);
      }
      break;
    }
    case QRF_STYLE_Stats:
    case QRF_STYLE_StatsEst: {
      i64 nCycle = 0;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
      sqlite3_stmt_scanstatus_v2(p->pStmt, -1, SQLITE_SCANSTAT_NCYCLE,
                                 SQLITE_SCANSTAT_COMPLEX, (void*)&nCycle);
#endif
      qrfEqpRender(p, nCycle);
      break;
    }
    case QRF_STYLE_Eqp: {
      qrfEqpRender(p, 0);
      break;
    }
  }
  qrfWrite(p);
  qrfStrErr(p, p->pOut);
  if( p->spec.pzOutput ){
    if( p->spec.pzOutput[0] ){
      sqlite3_int64 n, sz;
      char *zCombined;
      sz = strlen(p->spec.pzOutput[0]);
      n = sqlite3_str_length(p->pOut);
      zCombined = sqlite3_realloc64(p->spec.pzOutput[0], sz+n+1);
      if( zCombined==0 ){
        sqlite3_free(p->spec.pzOutput[0]);
        p->spec.pzOutput[0] = 0;
        qrfOom(p);
      }else{
        p->spec.pzOutput[0] = zCombined;
        memcpy(zCombined+sz, sqlite3_str_value(p->pOut), n+1);
      }
      sqlite3_free(sqlite3_str_finish(p->pOut));
    }else{
      p->spec.pzOutput[0] = sqlite3_str_finish(p->pOut);
    }
  }else if( p->pOut ){
    sqlite3_free(sqlite3_str_finish(p->pOut));
  }
  if( p->expMode>0 ){
    sqlite3_stmt_explain(p->pStmt, p->expMode-1);
  }
  if( p->actualWidth ){
    sqlite3_free(p->actualWidth);
  }
  if( p->pJTrans ){
    sqlite3 *db = sqlite3_db_handle(p->pJTrans);
    sqlite3_finalize(p->pJTrans);
    sqlite3_close(db);
  }
}

/*
** Run the prepared statement pStmt and format the results according
** to the specification provided in pSpec.  Return an error code.
** If pzErr is not NULL and if an error occurs, write an error message
** into *pzErr.
*/
int sqlite3_format_query_result(
  sqlite3_stmt *pStmt,                 /* Statement to evaluate */
  const sqlite3_qrf_spec *pSpec,       /* Format specification */
  char **pzErr                         /* Write error message here */
){
  Qrf qrf;         /* The new Qrf being created */

  if( pStmt==0 ) return SQLITE_OK;       /* No-op */
  if( pSpec==0 ) return SQLITE_MISUSE;
  qrfInitialize(&qrf, pStmt, pSpec, pzErr);
  switch( qrf.spec.eStyle ){
    case QRF_STYLE_Box:
    case QRF_STYLE_Column:
    case QRF_STYLE_Markdown: 
    case QRF_STYLE_Table: {
      /* Columnar modes require that the entire query be evaluated and the
      ** results stored in memory, so that we can compute column widths */
      qrfColumnar(&qrf);
      break;
    }
    case QRF_STYLE_Explain: {
      qrfExplain(&qrf);
      break;
    }
    case QRF_STYLE_StatsVm: {
      qrfScanStatusVm(&qrf);
      break;
    }
    case QRF_STYLE_Stats:
    case QRF_STYLE_StatsEst: {
      qrfEqpStats(&qrf);
      break;
    }
    default: {
      /* Non-columnar modes where the output can occur after each row
      ** of result is received */
      while( qrf.iErr==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
        qrfOneSimpleRow(&qrf);
      }
      break;
    }
  }
  qrfResetStmt(&qrf);
  qrfFinalize(&qrf);
  return qrf.iErr;
}

/************************* End ext/qrf/qrf.c ********************/

/* Use console I/O package as a direct INCLUDE. */
#define SQLITE_INTERNAL_LINKAGE static

#ifdef SQLITE_SHELL_FIDDLE
/* Deselect most features from the console I/O package for Fiddle. */
# define SQLITE_CIO_NO_REDIRECT
# define SQLITE_CIO_NO_CLASSIFY
# define SQLITE_CIO_NO_TRANSLATE
# define SQLITE_CIO_NO_SETMODE
# define SQLITE_CIO_NO_FLUSH
#endif

/*
** The source code for several run-time loadable extensions is inserted
** below by the ../tool/mkshellc.tcl script.  Before processing that included
** code, we need to override some macros to make the included program code
** work here in the middle of this regular program.
*/
#define SQLITE_EXTENSION_INIT1
#define SQLITE_EXTENSION_INIT2(X) (void)(X)

/************************* Begin ext/misc/windirent.h ******************/
/*
** 2025-06-05
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** An implementation of opendir(), readdir(), and closedir() for Windows,
** based on the FindFirstFile(), FindNextFile(), and FindClose() APIs
** of Win32.
**
** #include this file inside any C-code module that needs to use
** opendir()/readdir()/closedir().  This file is a no-op on non-Windows
** machines.  On Windows, static functions are defined that implement
** those standard interfaces.
*/
#if defined(_WIN32) && defined(_MSC_VER) && !defined(SQLITE_WINDIRENT_H)
#define SQLITE_WINDIRENT_H

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <io.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#ifndef FILENAME_MAX
# define FILENAME_MAX (260)
#endif
#ifndef S_ISREG
#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#endif
#ifndef S_ISDIR
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
#ifndef S_ISLNK
#define S_ISLNK(m) (0)
#endif
typedef unsigned short mode_t;

/* The dirent object for Windows is abbreviated.  The only field really
** usable by applications is d_name[].
*/
struct dirent {
 int d_ino;                  /* Inode number (synthesized) */
 unsigned d_attributes;      /* File attributes */
 char d_name[FILENAME_MAX];  /* Null-terminated filename */
};

/* The internals of DIR are opaque according to standards.  So it
** does not matter what we put here. */
typedef struct DIR DIR;
struct DIR {
  intptr_t d_handle;         /* Handle for findfirst()/findnext() */
  struct dirent cur;         /* Current entry */
};

/* Ignore hidden and system files */
#define WindowsFileToIgnore(a) \
    ((((a).attrib)&_A_HIDDEN) || (((a).attrib)&_A_SYSTEM))

/*
** Close a previously opened directory
*/
static int closedir(DIR *pDir){
  int rc = 0;
  if( pDir==0 ){
    return EINVAL;
  }
  if( pDir->d_handle!=0 && pDir->d_handle!=(-1) ){
    rc = _findclose(pDir->d_handle);
  }
  sqlite3_free(pDir);
  return rc;
}

/*
** Open a new directory.  The directory name should be UTF-8 encoded.
** appropriate translations happen automatically.
*/
static DIR *opendir(const char *zDirName){
  DIR *pDir;
  wchar_t *b1;
  sqlite3_int64 sz;
  struct _wfinddata_t data;

  pDir = sqlite3_malloc64( sizeof(DIR) );
  if( pDir==0 ) return 0;
  memset(pDir, 0, sizeof(DIR));
  memset(&data, 0, sizeof(data));
  sz = strlen(zDirName);
  b1 = sqlite3_malloc64( (sz+3)*sizeof(b1[0]) );
  if( b1==0 ){
    closedir(pDir);
    return NULL;
  }
  sz = MultiByteToWideChar(CP_UTF8, 0, zDirName, sz, b1, sz);
  b1[sz++] = '\\';
  b1[sz++] = '*';
  b1[sz] = 0;
  if( sz+1>sizeof(data.name)/sizeof(data.name[0]) ){
    closedir(pDir);
    sqlite3_free(b1);
    return NULL;
  }
  memcpy(data.name, b1, (sz+1)*sizeof(b1[0]));
  sqlite3_free(b1);
  pDir->d_handle = _wfindfirst(data.name, &data);
  if( pDir->d_handle<0 ){
    closedir(pDir);
    return NULL;
  }
  while( WindowsFileToIgnore(data) ){
    memset(&data, 0, sizeof(data));
    if( _wfindnext(pDir->d_handle, &data)==-1 ){
      closedir(pDir);
      return NULL;
    }
  }
  pDir->cur.d_ino = 0;
  pDir->cur.d_attributes = data.attrib;
  WideCharToMultiByte(CP_UTF8, 0, data.name, -1,
                      pDir->cur.d_name, FILENAME_MAX, 0, 0);
  return pDir;
}

/*
** Read the next entry from a directory.
**
** The returned struct-dirent object is managed by DIR.  It is only
** valid until the next readdir() or closedir() call.  Only the
** d_name[] field is meaningful.  The d_name[] value has been
** translated into UTF8.
*/
static struct dirent *readdir(DIR *pDir){
  struct _wfinddata_t data;
  if( pDir==0 ) return 0;
  if( (pDir->cur.d_ino++)==0 ){
    return &pDir->cur;
  }
  do{
    memset(&data, 0, sizeof(data));
    if( _wfindnext(pDir->d_handle, &data)==-1 ){
      return NULL;
    }
  }while( WindowsFileToIgnore(data) );
  pDir->cur.d_attributes = data.attrib;
  WideCharToMultiByte(CP_UTF8, 0, data.name, -1,
                      pDir->cur.d_name, FILENAME_MAX, 0, 0);
  return &pDir->cur;
}

#endif /* defined(_WIN32) && defined(_MSC_VER) */

/************************* End ext/misc/windirent.h ********************/
/************************* Begin ext/misc/memtrace.c ******************/
/*
** 2019-01-21
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements an extension that uses the SQLITE_CONFIG_MALLOC
** mechanism to add a tracing layer on top of SQLite.  If this extension
** is registered prior to sqlite3_initialize(), it will cause all memory
** allocation activities to be logged on standard output, or to some other
** FILE specified by the initializer.
**
** This file needs to be compiled into the application that uses it.
**
** This extension is used to implement the --memtrace option of the
** command-line shell.
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>

/* The original memory allocation routines */
static sqlite3_mem_methods memtraceBase;
static FILE *memtraceOut;

/* Methods that trace memory allocations */
static void *memtraceMalloc(int n){
  if( memtraceOut ){
    fprintf(memtraceOut, "MEMTRACE: allocate %d bytes\n", 
            memtraceBase.xRoundup(n));
  }
  return memtraceBase.xMalloc(n);
}
static void memtraceFree(void *p){
  if( p==0 ) return;
  if( memtraceOut ){
    fprintf(memtraceOut, "MEMTRACE: free %d bytes\n", memtraceBase.xSize(p));
  }
  memtraceBase.xFree(p);
}
static void *memtraceRealloc(void *p, int n){
  if( p==0 ) return memtraceMalloc(n);
  if( n==0 ){
    memtraceFree(p);
    return 0;
  }
  if( memtraceOut ){
    fprintf(memtraceOut, "MEMTRACE: resize %d -> %d bytes\n",
            memtraceBase.xSize(p), memtraceBase.xRoundup(n));
  }
  return memtraceBase.xRealloc(p, n);
}
static int memtraceSize(void *p){
  return memtraceBase.xSize(p);
}
static int memtraceRoundup(int n){
  return memtraceBase.xRoundup(n);
}
static int memtraceInit(void *p){
  return memtraceBase.xInit(p);
}
static void memtraceShutdown(void *p){
  memtraceBase.xShutdown(p);
}

/* The substitute memory allocator */
static sqlite3_mem_methods ersaztMethods = {
  memtraceMalloc,
  memtraceFree,
  memtraceRealloc,
  memtraceSize,
  memtraceRoundup,
  memtraceInit,
  memtraceShutdown,
  0
};

/* Begin tracing memory allocations to out. */
int sqlite3MemTraceActivate(FILE *out){
  int rc = SQLITE_OK;
  if( memtraceBase.xMalloc==0 ){
    rc = sqlite3_config(SQLITE_CONFIG_GETMALLOC, &memtraceBase);
    if( rc==SQLITE_OK ){
      rc = sqlite3_config(SQLITE_CONFIG_MALLOC, &ersaztMethods);
    }
  }
  memtraceOut = out;
  return rc;
}

/* Deactivate memory tracing */
int sqlite3MemTraceDeactivate(void){
  int rc = SQLITE_OK;
  if( memtraceBase.xMalloc!=0 ){
    rc = sqlite3_config(SQLITE_CONFIG_MALLOC, &memtraceBase);
    if( rc==SQLITE_OK ){
      memset(&memtraceBase, 0, sizeof(memtraceBase));
    }
  }
  memtraceOut = 0;
  return rc;
}

/************************* End ext/misc/memtrace.c ********************/
/************************* Begin ext/misc/pcachetrace.c ******************/
/*
** 2023-06-21
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements an extension that uses the SQLITE_CONFIG_PCACHE2
** mechanism to add a tracing layer on top of pluggable page cache of
** SQLite.  If this extension is registered prior to sqlite3_initialize(),
** it will cause all page cache activities to be logged on standard output,
** or to some other FILE specified by the initializer.
**
** This file needs to be compiled into the application that uses it.
**
** This extension is used to implement the --pcachetrace option of the
** command-line shell.
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>

/* The original page cache routines */
static sqlite3_pcache_methods2 pcacheBase;
static FILE *pcachetraceOut;

/* Methods that trace pcache activity */
static int pcachetraceInit(void *pArg){
  int nRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xInit(%p)\n", pArg);
  }
  nRes = pcacheBase.xInit(pArg);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xInit(%p) -> %d\n", pArg, nRes);
  }
  return nRes;
}
static void pcachetraceShutdown(void *pArg){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xShutdown(%p)\n", pArg);
  }
  pcacheBase.xShutdown(pArg);
}
static sqlite3_pcache *pcachetraceCreate(int szPage, int szExtra, int bPurge){
  sqlite3_pcache *pRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xCreate(%d,%d,%d)\n",
            szPage, szExtra, bPurge);
  }
  pRes = pcacheBase.xCreate(szPage, szExtra, bPurge);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xCreate(%d,%d,%d) -> %p\n",
            szPage, szExtra, bPurge, pRes);
  }
  return pRes;
}
static void pcachetraceCachesize(sqlite3_pcache *p, int nCachesize){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xCachesize(%p, %d)\n", p, nCachesize);
  }
  pcacheBase.xCachesize(p, nCachesize);
}
static int pcachetracePagecount(sqlite3_pcache *p){
  int nRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xPagecount(%p)\n", p);
  }
  nRes = pcacheBase.xPagecount(p);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xPagecount(%p) -> %d\n", p, nRes);
  }
  return nRes;
}
static sqlite3_pcache_page *pcachetraceFetch(
  sqlite3_pcache *p,
  unsigned key,
  int crFg
){
  sqlite3_pcache_page *pRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xFetch(%p,%u,%d)\n", p, key, crFg);
  }
  pRes = pcacheBase.xFetch(p, key, crFg);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xFetch(%p,%u,%d) -> %p\n",
            p, key, crFg, pRes);
  }
  return pRes;
}
static void pcachetraceUnpin(
  sqlite3_pcache *p,
  sqlite3_pcache_page *pPg,
  int bDiscard
){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xUnpin(%p, %p, %d)\n",
            p, pPg, bDiscard);
  }
  pcacheBase.xUnpin(p, pPg, bDiscard);
}
static void pcachetraceRekey(
  sqlite3_pcache *p,
  sqlite3_pcache_page *pPg,
  unsigned oldKey,
  unsigned newKey
){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xRekey(%p, %p, %u, %u)\n",
        p, pPg, oldKey, newKey);
  }
  pcacheBase.xRekey(p, pPg, oldKey, newKey);
}
static void pcachetraceTruncate(sqlite3_pcache *p, unsigned n){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xTruncate(%p, %u)\n", p, n);
  }
  pcacheBase.xTruncate(p, n);
}
static void pcachetraceDestroy(sqlite3_pcache *p){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xDestroy(%p)\n", p);
  }
  pcacheBase.xDestroy(p);
}
static void pcachetraceShrink(sqlite3_pcache *p){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xShrink(%p)\n", p);
  }
  pcacheBase.xShrink(p);
}

/* The substitute pcache methods */
static sqlite3_pcache_methods2 ersaztPcacheMethods = {
  0,
  0,
  pcachetraceInit,
  pcachetraceShutdown,
  pcachetraceCreate,
  pcachetraceCachesize,
  pcachetracePagecount,
  pcachetraceFetch,
  pcachetraceUnpin,
  pcachetraceRekey,
  pcachetraceTruncate,
  pcachetraceDestroy,
  pcachetraceShrink
};

/* Begin tracing memory allocations to out. */
int sqlite3PcacheTraceActivate(FILE *out){
  int rc = SQLITE_OK;
  if( pcacheBase.xFetch==0 ){
    rc = sqlite3_config(SQLITE_CONFIG_GETPCACHE2, &pcacheBase);
    if( rc==SQLITE_OK ){
      rc = sqlite3_config(SQLITE_CONFIG_PCACHE2, &ersaztPcacheMethods);
    }
  }
  pcachetraceOut = out;
  return rc;
}

/* Deactivate memory tracing */
int sqlite3PcacheTraceDeactivate(void){
  int rc = SQLITE_OK;
  if( pcacheBase.xFetch!=0 ){
    rc = sqlite3_config(SQLITE_CONFIG_PCACHE2, &pcacheBase);
    if( rc==SQLITE_OK ){
      memset(&pcacheBase, 0, sizeof(pcacheBase));
    }
  }
  pcachetraceOut = 0;
  return rc;
}

/************************* End ext/misc/pcachetrace.c ********************/
/************************* Begin ext/misc/shathree.c ******************/
/*
** 2017-03-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions that compute SHA3 hashes
** in the way described by the (U.S.) NIST FIPS 202 SHA-3 Standard.
** Three SQL functions are implemented:
**
**     sha3(X,SIZE)
**     sha3_agg(Y,SIZE)
**     sha3_query(Z,SIZE)
**
** The sha3(X) function computes the SHA3 hash of the input X, or NULL if
** X is NULL.  If inputs X is text, the UTF-8 rendering of that text is
** used to compute the hash.  If X is a BLOB, then the binary data of the
** blob is used to compute the hash.  If X is an integer or real number,
** then that number if converted into UTF-8 text and the hash is computed
** over the text.
**
** The sha3_agg(Y) function computes the SHA3 hash of all Y inputs.  Since
** order is important for the hash, it is recommended that the Y expression
** by followed by an ORDER BY clause to guarantee that the inputs occur
** in the desired order.
**
** The sha3_query(Y) function evaluates all queries in the SQL statements of Y
** and returns a hash of their results.
**
** The SIZE argument is optional.  If omitted, the SHA3-256 hash algorithm
** is used.  If SIZE is included it must be one of the integers 224, 256,
** 384, or 512, to determine SHA3 hash variant that is computed.
**
** Because the sha3_agg() and sha3_query() functions compute a hash over
** multiple values, the values are encode to use include type information.
**
** In sha3_agg(), the sequence of bytes that gets hashed for each input
** Y depends on the datatype of Y:
**
**    typeof(Y)='null'         A single "N" is hashed.  (One byte)
**
**    typeof(Y)='integer'      The data hash is the character "I" followed
**                             by an 8-byte big-endian binary of the
**                             64-bit signed integer.  (Nine bytes total.)
**
**    typeof(Y)='real'         The character "F" followed by an 8-byte
**                             big-ending binary of the double.  (Nine
**                             bytes total.)
**
**    typeof(Y)='text'         The hash is over prefix "Tnnn:" followed
**                             by the UTF8 encoding of the text.  The "nnn"
**                             in the prefix is the minimum-length decimal
**                             representation of the octet_length of the text.
**                             Notice the ":" at the end of the prefix, which
**                             is needed to separate the prefix from the
**                             content in cases where the content starts
**                             with a digit.
**
**    typeof(Y)='blob'         The hash is taken over prefix "Bnnn:" followed
**                             by the binary content of the blob.  The "nnn"
**                             in the prefix is the minimum-length decimal
**                             representation of the byte-length of the blob.
**
** According to the rules above, all of the following SELECT statements
** should return TRUE:
**
**    SELECT sha3(1) = sha3('1');
**
**    SELECT sha3('hello') = sha3(x'68656c6c6f');
**
**    WITH a(x) AS (VALUES('xyzzy'))
**      SELECT sha3_agg(x) = sha3('T5:xyzzy')            FROM a;
**
**    WITH a(x) AS (VALUES(x'010203'))
**      SELECT sha3_agg(x) = sha3(x'42333a010203')       FROM a;
**
**    WITH a(x) AS (VALUES(0x123456))
**      SELECT sha3_agg(x) = sha3(x'490000000000123456') FROM a;
**
**    WITH a(x) AS (VALUES(100.015625))
**      SELECT sha3_agg(x) = sha3(x'464059010000000000') FROM a;
**
**    WITH a(x) AS (VALUES(NULL))
**      SELECT sha3_agg(x) = sha3('N') FROM a;
**
**
** In sha3_query(), individual column values are encoded as with
** sha3_agg(), but with the addition that a single "R" character is
** inserted at the start of each row.
**
** Note that sha3_agg() hashes rows for which Y is NULL.  Add a FILTER
** clause if NULL rows should be excluded:
**
**    SELECT sha3_agg(x ORDER BY rowid) FILTER(WHERE x NOT NULL) FROM t1;
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <stdarg.h>

#ifndef SQLITE_AMALGAMATION
/* typedef sqlite3_uint64 u64; */
#endif /* SQLITE_AMALGAMATION */

/******************************************************************************
** The Hash Engine
*/
/*
** Macros to determine whether the machine is big or little endian,
** and whether or not that determination is run-time or compile-time.
**
** For best performance, an attempt is made to guess at the byte-order
** using C-preprocessor macros.  If that is unsuccessful, or if
** -DSHA3_BYTEORDER=0 is set, then byte-order is determined
** at run-time.
*/
#ifndef SHA3_BYTEORDER
# if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
     defined(__arm__)
#   define SHA3_BYTEORDER    1234
# elif defined(sparc)    || defined(__ppc__)
#   define SHA3_BYTEORDER    4321
# else
#   define SHA3_BYTEORDER 0
# endif
#endif


/*
** State structure for a SHA3 hash in progress
*/
typedef struct SHA3Context SHA3Context;
struct SHA3Context {
  union {
    u64 s[25];                /* Keccak state. 5x5 lines of 64 bits each */
    unsigned char x[1600];    /* ... or 1600 bytes */
  } u;
  unsigned nRate;        /* Bytes of input accepted per Keccak iteration */
  unsigned nLoaded;      /* Input bytes loaded into u.x[] so far this cycle */
  unsigned ixMask;       /* Insert next input into u.x[nLoaded^ixMask]. */
  unsigned iSize;        /* 224, 256, 358, or 512 */
};

/*
** A single step of the Keccak mixing function for a 1600-bit state
*/
static void KeccakF1600Step(SHA3Context *p){
  int i;
  u64 b0, b1, b2, b3, b4;
  u64 c0, c1, c2, c3, c4;
  u64 d0, d1, d2, d3, d4;
  static const u64 RC[] = {
    0x0000000000000001ULL,  0x0000000000008082ULL,
    0x800000000000808aULL,  0x8000000080008000ULL,
    0x000000000000808bULL,  0x0000000080000001ULL,
    0x8000000080008081ULL,  0x8000000000008009ULL,
    0x000000000000008aULL,  0x0000000000000088ULL,
    0x0000000080008009ULL,  0x000000008000000aULL,
    0x000000008000808bULL,  0x800000000000008bULL,
    0x8000000000008089ULL,  0x8000000000008003ULL,
    0x8000000000008002ULL,  0x8000000000000080ULL,
    0x000000000000800aULL,  0x800000008000000aULL,
    0x8000000080008081ULL,  0x8000000000008080ULL,
    0x0000000080000001ULL,  0x8000000080008008ULL
  };
# define a00 (p->u.s[0])
# define a01 (p->u.s[1])
# define a02 (p->u.s[2])
# define a03 (p->u.s[3])
# define a04 (p->u.s[4])
# define a10 (p->u.s[5])
# define a11 (p->u.s[6])
# define a12 (p->u.s[7])
# define a13 (p->u.s[8])
# define a14 (p->u.s[9])
# define a20 (p->u.s[10])
# define a21 (p->u.s[11])
# define a22 (p->u.s[12])
# define a23 (p->u.s[13])
# define a24 (p->u.s[14])
# define a30 (p->u.s[15])
# define a31 (p->u.s[16])
# define a32 (p->u.s[17])
# define a33 (p->u.s[18])
# define a34 (p->u.s[19])
# define a40 (p->u.s[20])
# define a41 (p->u.s[21])
# define a42 (p->u.s[22])
# define a43 (p->u.s[23])
# define a44 (p->u.s[24])
# define ROL64(a,x) ((a<<x)|(a>>(64-x)))

  for(i=0; i<24; i+=4){
    c0 = a00^a10^a20^a30^a40;
    c1 = a01^a11^a21^a31^a41;
    c2 = a02^a12^a22^a32^a42;
    c3 = a03^a13^a23^a33^a43;
    c4 = a04^a14^a24^a34^a44;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a11^d1), 44);
    b2 = ROL64((a22^d2), 43);
    b3 = ROL64((a33^d3), 21);
    b4 = ROL64((a44^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i];
    a11 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a20^d0), 3);
    b3 = ROL64((a31^d1), 45);
    b4 = ROL64((a42^d2), 61);
    b0 = ROL64((a03^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a20 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a40^d0), 18);
    b0 = ROL64((a01^d1), 1);
    b1 = ROL64((a12^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a34^d4), 8);
    a40 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a10^d0), 36);
    b2 = ROL64((a21^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a43^d3), 56);
    b0 = ROL64((a04^d4), 27);
    a10 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a30^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a02^d2), 62);
    b1 = ROL64((a13^d3), 55);
    b2 = ROL64((a24^d4), 39);
    a30 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    c0 = a00^a20^a40^a10^a30;
    c1 = a11^a31^a01^a21^a41;
    c2 = a22^a42^a12^a32^a02;
    c3 = a33^a03^a23^a43^a13;
    c4 = a44^a14^a34^a04^a24;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a31^d1), 44);
    b2 = ROL64((a12^d2), 43);
    b3 = ROL64((a43^d3), 21);
    b4 = ROL64((a24^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+1];
    a31 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a40^d0), 3);
    b3 = ROL64((a21^d1), 45);
    b4 = ROL64((a02^d2), 61);
    b0 = ROL64((a33^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a40 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a30^d0), 18);
    b0 = ROL64((a11^d1), 1);
    b1 = ROL64((a42^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a04^d4), 8);
    a30 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a20^d0), 36);
    b2 = ROL64((a01^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a13^d3), 56);
    b0 = ROL64((a44^d4), 27);
    a20 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a10^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a22^d2), 62);
    b1 = ROL64((a03^d3), 55);
    b2 = ROL64((a34^d4), 39);
    a10 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    c0 = a00^a40^a30^a20^a10;
    c1 = a31^a21^a11^a01^a41;
    c2 = a12^a02^a42^a32^a22;
    c3 = a43^a33^a23^a13^a03;
    c4 = a24^a14^a04^a44^a34;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a21^d1), 44);
    b2 = ROL64((a42^d2), 43);
    b3 = ROL64((a13^d3), 21);
    b4 = ROL64((a34^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+2];
    a21 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a30^d0), 3);
    b3 = ROL64((a01^d1), 45);
    b4 = ROL64((a22^d2), 61);
    b0 = ROL64((a43^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a30 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a10^d0), 18);
    b0 = ROL64((a31^d1), 1);
    b1 = ROL64((a02^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a44^d4), 8);
    a10 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a40^d0), 36);
    b2 = ROL64((a11^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a03^d3), 56);
    b0 = ROL64((a24^d4), 27);
    a40 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a20^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a12^d2), 62);
    b1 = ROL64((a33^d3), 55);
    b2 = ROL64((a04^d4), 39);
    a20 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    c0 = a00^a30^a10^a40^a20;
    c1 = a21^a01^a31^a11^a41;
    c2 = a42^a22^a02^a32^a12;
    c3 = a13^a43^a23^a03^a33;
    c4 = a34^a14^a44^a24^a04;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a01^d1), 44);
    b2 = ROL64((a02^d2), 43);
    b3 = ROL64((a03^d3), 21);
    b4 = ROL64((a04^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+3];
    a01 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a10^d0), 3);
    b3 = ROL64((a11^d1), 45);
    b4 = ROL64((a12^d2), 61);
    b0 = ROL64((a13^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a10 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a20^d0), 18);
    b0 = ROL64((a21^d1), 1);
    b1 = ROL64((a22^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a24^d4), 8);
    a20 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a30^d0), 36);
    b2 = ROL64((a31^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a33^d3), 56);
    b0 = ROL64((a34^d4), 27);
    a30 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a40^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a42^d2), 62);
    b1 = ROL64((a43^d3), 55);
    b2 = ROL64((a44^d4), 39);
    a40 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );
  }
}

/*
** Initialize a new hash.  iSize determines the size of the hash
** in bits and should be one of 224, 256, 384, or 512.  Or iSize
** can be zero to use the default hash size of 256 bits.
*/
static void SHA3Init(SHA3Context *p, int iSize){
  memset(p, 0, sizeof(*p));
  p->iSize = iSize;
  if( iSize>=128 && iSize<=512 ){
    p->nRate = (1600 - ((iSize + 31)&~31)*2)/8;
  }else{
    p->nRate = (1600 - 2*256)/8;
  }
#if SHA3_BYTEORDER==1234
  /* Known to be little-endian at compile-time. No-op */
#elif SHA3_BYTEORDER==4321
  p->ixMask = 7;  /* Big-endian */
#else
  {
    static unsigned int one = 1;
    if( 1==*(unsigned char*)&one ){
      /* Little endian.  No byte swapping. */
      p->ixMask = 0;
    }else{
      /* Big endian.  Byte swap. */
      p->ixMask = 7;
    }
  }
#endif
}

/*
** Make consecutive calls to the SHA3Update function to add new content
** to the hash
*/
static void SHA3Update(
  SHA3Context *p,
  const unsigned char *aData,
  unsigned int nData
){
  unsigned int i = 0;
  if( aData==0 ) return;
#if SHA3_BYTEORDER==1234
  if( (p->nLoaded % 8)==0 && ((aData - (const unsigned char*)0)&7)==0 ){
    for(; i+7<nData; i+=8){
      p->u.s[p->nLoaded/8] ^= *(u64*)&aData[i];
      p->nLoaded += 8;
      if( p->nLoaded>=p->nRate ){
        KeccakF1600Step(p);
        p->nLoaded = 0;
      }
    }
  }
#endif
  for(; i<nData; i++){
#if SHA3_BYTEORDER==1234
    p->u.x[p->nLoaded] ^= aData[i];
#elif SHA3_BYTEORDER==4321
    p->u.x[p->nLoaded^0x07] ^= aData[i];
#else
    p->u.x[p->nLoaded^p->ixMask] ^= aData[i];
#endif
    p->nLoaded++;
    if( p->nLoaded==p->nRate ){
      KeccakF1600Step(p);
      p->nLoaded = 0;
    }
  }
}

/*
** After all content has been added, invoke SHA3Final() to compute
** the final hash.  The function returns a pointer to the binary
** hash value.
*/
static unsigned char *SHA3Final(SHA3Context *p){
  unsigned int i;
  if( p->nLoaded==p->nRate-1 ){
    const unsigned char c1 = 0x86;
    SHA3Update(p, &c1, 1);
  }else{
    const unsigned char c2 = 0x06;
    const unsigned char c3 = 0x80;
    SHA3Update(p, &c2, 1);
    p->nLoaded = p->nRate - 1;
    SHA3Update(p, &c3, 1);
  }
  for(i=0; i<p->nRate; i++){
    p->u.x[i+p->nRate] = p->u.x[i^p->ixMask];
  }
  return &p->u.x[p->nRate];
}
/* End of the hashing logic
*****************************************************************************/

/*
** Implementation of the sha3(X,SIZE) function.
**
** Return a BLOB which is the SIZE-bit SHA3 hash of X.  The default
** size is 256.  If X is a BLOB, it is hashed as is.  
** For all other non-NULL types of input, X is converted into a UTF-8 string
** and the string is hashed without the trailing 0x00 terminator.  The hash
** of a NULL value is NULL.
*/
static void sha3Func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  SHA3Context cx;
  int eType = sqlite3_value_type(argv[0]);
  int nByte = sqlite3_value_bytes(argv[0]);
  int iSize;
  if( argc==1 ){
    iSize = 256;
  }else{
    iSize = sqlite3_value_int(argv[1]);
    if( iSize!=224 && iSize!=256 && iSize!=384 && iSize!=512 ){
      sqlite3_result_error(context, "SHA3 size should be one of: 224 256 "
                                    "384 512", -1);
      return;
    }
  }
  if( eType==SQLITE_NULL ) return;
  SHA3Init(&cx, iSize);
  if( eType==SQLITE_BLOB ){
    SHA3Update(&cx, sqlite3_value_blob(argv[0]), nByte);
  }else{
    SHA3Update(&cx, sqlite3_value_text(argv[0]), nByte);
  }
  sqlite3_result_blob(context, SHA3Final(&cx), iSize/8, SQLITE_TRANSIENT);
}

/* Compute a string using sqlite3_vsnprintf() with a maximum length
** of 50 bytes and add it to the hash.
*/
static void sha3_step_vformat(
  SHA3Context *p,                 /* Add content to this context */
  const char *zFormat,
  ...
){
  va_list ap;
  int n;
  char zBuf[50];
  va_start(ap, zFormat);
  sqlite3_vsnprintf(sizeof(zBuf),zBuf,zFormat,ap);
  va_end(ap);
  n = (int)strlen(zBuf);
  SHA3Update(p, (unsigned char*)zBuf, n);
}

/*
** Update a SHA3Context using a single sqlite3_value.
*/
static void sha3UpdateFromValue(SHA3Context *p, sqlite3_value *pVal){
  switch( sqlite3_value_type(pVal) ){
    case SQLITE_NULL: {
      SHA3Update(p, (const unsigned char*)"N",1);
      break;
    }
    case SQLITE_INTEGER: {
      sqlite3_uint64 u;
      int j;
      unsigned char x[9];
      sqlite3_int64 v = sqlite3_value_int64(pVal);
      memcpy(&u, &v, 8);
      for(j=8; j>=1; j--){
        x[j] = u & 0xff;
        u >>= 8;
      }
      x[0] = 'I';
      SHA3Update(p, x, 9);
      break;
    }
    case SQLITE_FLOAT: {
      sqlite3_uint64 u;
      int j;
      unsigned char x[9];
      double r = sqlite3_value_double(pVal);
      memcpy(&u, &r, 8);
      for(j=8; j>=1; j--){
        x[j] = u & 0xff;
        u >>= 8;
      }
      x[0] = 'F';
      SHA3Update(p,x,9);
      break;
    }
    case SQLITE_TEXT: {
      int n2 = sqlite3_value_bytes(pVal);
      const unsigned char *z2 = sqlite3_value_text(pVal);
      sha3_step_vformat(p,"T%d:",n2);
      SHA3Update(p, z2, n2);
      break;
    }
    case SQLITE_BLOB: {
      int n2 = sqlite3_value_bytes(pVal);
      const unsigned char *z2 = sqlite3_value_blob(pVal);
      sha3_step_vformat(p,"B%d:",n2);
      SHA3Update(p, z2, n2);
      break;
    }
  }
}

/*
** Implementation of the sha3_query(SQL,SIZE) function.
**
** This function compiles and runs the SQL statement(s) given in the
** argument. The results are hashed using a SIZE-bit SHA3.  The default
** size is 256.
**
** The format of the byte stream that is hashed is summarized as follows:
**
**       S<n>:<sql>
**       R
**       N
**       I<int>
**       F<ieee-float>
**       B<size>:<bytes>
**       T<size>:<text>
**
** <sql> is the original SQL text for each statement run and <n> is
** the size of that text.  The SQL text is UTF-8.  A single R character
** occurs before the start of each row.  N means a NULL value.
** I mean an 8-byte little-endian integer <int>.  F is a floating point
** number with an 8-byte little-endian IEEE floating point value <ieee-float>.
** B means blobs of <size> bytes.  T means text rendered as <size>
** bytes of UTF-8.  The <n> and <size> values are expressed as an ASCII
** text integers.
**
** For each SQL statement in the X input, there is one S segment.  Each
** S segment is followed by zero or more R segments, one for each row in the
** result set.  After each R, there are one or more N, I, F, B, or T segments,
** one for each column in the result set.  Segments are concatentated directly
** with no delimiters of any kind.
*/
static void sha3QueryFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3 *db = sqlite3_context_db_handle(context);
  const char *zSql = (const char*)sqlite3_value_text(argv[0]);
  sqlite3_stmt *pStmt = 0;
  int nCol;                   /* Number of columns in the result set */
  int i;                      /* Loop counter */
  int rc;
  int n;
  const char *z;
  SHA3Context cx;
  int iSize;

  if( argc==1 ){
    iSize = 256;
  }else{
    iSize = sqlite3_value_int(argv[1]);
    if( iSize!=224 && iSize!=256 && iSize!=384 && iSize!=512 ){
      sqlite3_result_error(context, "SHA3 size should be one of: 224 256 "
                                    "384 512", -1);
      return;
    }
  }
  if( zSql==0 ) return;
  SHA3Init(&cx, iSize);
  while( zSql[0] ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zSql);
    if( rc ){
      char *zMsg = sqlite3_mprintf("error SQL statement [%s]: %s",
                                   zSql, sqlite3_errmsg(db));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    if( !sqlite3_stmt_readonly(pStmt) ){
      char *zMsg = sqlite3_mprintf("non-query: [%s]", sqlite3_sql(pStmt));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    nCol = sqlite3_column_count(pStmt);
    z = sqlite3_sql(pStmt);
    if( z ){
      n = (int)strlen(z);
      sha3_step_vformat(&cx,"S%d:",n);
      SHA3Update(&cx,(unsigned char*)z,n);
    }

    /* Compute a hash over the result of the query */
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      SHA3Update(&cx,(const unsigned char*)"R",1);
      for(i=0; i<nCol; i++){
        sha3UpdateFromValue(&cx, sqlite3_column_value(pStmt,i));
      }
    }
    sqlite3_finalize(pStmt);
  }
  sqlite3_result_blob(context, SHA3Final(&cx), iSize/8, SQLITE_TRANSIENT);
}

/*
** xStep function for sha3_agg().
*/
static void sha3AggStep(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  SHA3Context *p;
  p = (SHA3Context*)sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( p->nRate==0 ){
    int sz = 256;
    if( argc==2 ){
      sz = sqlite3_value_int(argv[1]);
      if( sz!=224 && sz!=384 && sz!=512 ){
        sz = 256;
      }
    }
    SHA3Init(p, sz);
  }
  sha3UpdateFromValue(p, argv[0]);
}


/*
** xFinal function for sha3_agg().
*/
static void sha3AggFinal(sqlite3_context *context){
  SHA3Context *p;
  p = (SHA3Context*)sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( p->iSize ){
    sqlite3_result_blob(context, SHA3Final(p), p->iSize/8, SQLITE_TRANSIENT);
  }
}



#ifdef _WIN32

#endif
int sqlite3_shathree_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sha3", 1,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, sha3Func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3", 2,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, sha3Func, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_agg", 1,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, 0, sha3AggStep, sha3AggFinal);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_agg", 2,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, 0, sha3AggStep, sha3AggFinal);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_query", 1,
                      SQLITE_UTF8 | SQLITE_DIRECTONLY,
                      0, sha3QueryFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_query", 2,
                      SQLITE_UTF8 | SQLITE_DIRECTONLY,
                      0, sha3QueryFunc, 0, 0);
  }
  return rc;
}
#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  return sqlite3_shathree_init(db, pzErrMsg, pApi);
}
#endif

/************************* End ext/misc/shathree.c ********************/
/************************* Begin ext/misc/sha1.c ******************/
/*
** 2017-01-27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions that compute SHA1 hashes.
** Two SQL functions are implemented:
**
**     sha1(X)
**     sha1_query(Y)
**
** The sha1(X) function computes the SHA1 hash of the input X, or NULL if
** X is NULL.
**
** The sha1_query(Y) function evalutes all queries in the SQL statements of Y
** and returns a hash of their results.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <stdarg.h>

/******************************************************************************
** The Hash Engine
*/
/* Context for the SHA1 hash */
typedef struct SHA1Context SHA1Context;
struct SHA1Context {
  unsigned int state[5];
  unsigned int count[2];
  unsigned char buffer[64];
};

#define SHA_ROT(x,l,r) ((x) << (l) | (x) >> (r))
#define rol(x,k) SHA_ROT(x,k,32-(k))
#define ror(x,k) SHA_ROT(x,32-(k),k)

#define blk0le(i) (block[i] = (ror(block[i],8)&0xFF00FF00) \
    |(rol(block[i],8)&0x00FF00FF))
#define blk0be(i) block[i]
#define blk(i) (block[i&15] = rol(block[(i+13)&15]^block[(i+8)&15] \
    ^block[(i+2)&15]^block[i&15],1))

/*
 * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
 *
 * Rl0() for little-endian and Rb0() for big-endian.  Endianness is
 * determined at run-time.
 */
#define Rl0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0le(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define Rb0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0be(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define R1(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define R2(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=ror(w,2);
#define R3(v,w,x,y,z,i) \
    z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=ror(w,2);
#define R4(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=ror(w,2);

/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */
static void SHA1Transform(unsigned int state[5], const unsigned char buffer[64]){
  unsigned int qq[5]; /* a, b, c, d, e; */
  static int one = 1;
  unsigned int block[16];
  memcpy(block, buffer, 64);
  memcpy(qq,state,5*sizeof(unsigned int));

#define a qq[0]
#define b qq[1]
#define c qq[2]
#define d qq[3]
#define e qq[4]

  /* Copy p->state[] to working vars */
  /*
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];
  */

  /* 4 rounds of 20 operations each. Loop unrolled. */
  if( 1 == *(unsigned char*)&one ){
    Rl0(a,b,c,d,e, 0); Rl0(e,a,b,c,d, 1); Rl0(d,e,a,b,c, 2); Rl0(c,d,e,a,b, 3);
    Rl0(b,c,d,e,a, 4); Rl0(a,b,c,d,e, 5); Rl0(e,a,b,c,d, 6); Rl0(d,e,a,b,c, 7);
    Rl0(c,d,e,a,b, 8); Rl0(b,c,d,e,a, 9); Rl0(a,b,c,d,e,10); Rl0(e,a,b,c,d,11);
    Rl0(d,e,a,b,c,12); Rl0(c,d,e,a,b,13); Rl0(b,c,d,e,a,14); Rl0(a,b,c,d,e,15);
  }else{
    Rb0(a,b,c,d,e, 0); Rb0(e,a,b,c,d, 1); Rb0(d,e,a,b,c, 2); Rb0(c,d,e,a,b, 3);
    Rb0(b,c,d,e,a, 4); Rb0(a,b,c,d,e, 5); Rb0(e,a,b,c,d, 6); Rb0(d,e,a,b,c, 7);
    Rb0(c,d,e,a,b, 8); Rb0(b,c,d,e,a, 9); Rb0(a,b,c,d,e,10); Rb0(e,a,b,c,d,11);
    Rb0(d,e,a,b,c,12); Rb0(c,d,e,a,b,13); Rb0(b,c,d,e,a,14); Rb0(a,b,c,d,e,15);
  }
  R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
  R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
  R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
  R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
  R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
  R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
  R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
  R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
  R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
  R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
  R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
  R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
  R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
  R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
  R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
  R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);

  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;

#undef a
#undef b
#undef c
#undef d
#undef e
}


/* Initialize a SHA1 context */
static void hash_init(SHA1Context *p){
  /* SHA1 initialization constants */
  p->state[0] = 0x67452301;
  p->state[1] = 0xEFCDAB89;
  p->state[2] = 0x98BADCFE;
  p->state[3] = 0x10325476;
  p->state[4] = 0xC3D2E1F0;
  p->count[0] = p->count[1] = 0;
}

/* Add new content to the SHA1 hash */
static void hash_step(
  SHA1Context *p,                 /* Add content to this context */
  const unsigned char *data,      /* Data to be added */
  unsigned int len                /* Number of bytes in data */
){
  unsigned int i, j;

  j = p->count[0];
  if( (p->count[0] += len << 3) < j ){
    p->count[1] += (len>>29)+1;
  }
  j = (j >> 3) & 63;
  if( (j + len) > 63 ){
    (void)memcpy(&p->buffer[j], data, (i = 64-j));
    SHA1Transform(p->state, p->buffer);
    for(; i + 63 < len; i += 64){
      SHA1Transform(p->state, &data[i]);
    }
    j = 0;
  }else{
    i = 0;
  }
  (void)memcpy(&p->buffer[j], &data[i], len - i);
}

/* Compute a string using sqlite3_vsnprintf() and hash it */
static void hash_step_vformat(
  SHA1Context *p,                 /* Add content to this context */
  const char *zFormat,
  ...
){
  va_list ap;
  int n;
  char zBuf[50];
  va_start(ap, zFormat);
  sqlite3_vsnprintf(sizeof(zBuf),zBuf,zFormat,ap);
  va_end(ap);
  n = (int)strlen(zBuf);
  hash_step(p, (unsigned char*)zBuf, n);
}


/* Add padding and compute the message digest.  Render the
** message digest as lower-case hexadecimal and put it into
** zOut[].  zOut[] must be at least 41 bytes long. */
static void hash_finish(
  SHA1Context *p,           /* The SHA1 context to finish and render */
  char *zOut,               /* Store hex or binary hash here */
  int bAsBinary             /* 1 for binary hash, 0 for hex hash */
){
  unsigned int i;
  unsigned char finalcount[8];
  unsigned char digest[20];
  static const char zEncode[] = "0123456789abcdef";

  for (i = 0; i < 8; i++){
    finalcount[i] = (unsigned char)((p->count[(i >= 4 ? 0 : 1)]
       >> ((3-(i & 3)) * 8) ) & 255); /* Endian independent */
  }
  hash_step(p, (const unsigned char *)"\200", 1);
  while ((p->count[0] & 504) != 448){
    hash_step(p, (const unsigned char *)"\0", 1);
  }
  hash_step(p, finalcount, 8);  /* Should cause a SHA1Transform() */
  for (i = 0; i < 20; i++){
    digest[i] = (unsigned char)((p->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
  }
  if( bAsBinary ){
    memcpy(zOut, digest, 20);
  }else{
    for(i=0; i<20; i++){
      zOut[i*2] = zEncode[(digest[i]>>4)&0xf];
      zOut[i*2+1] = zEncode[digest[i] & 0xf];
    }
    zOut[i*2]= 0;
  }
}
/* End of the hashing logic
*****************************************************************************/

/*
** Two SQL functions:  sha1(X) and sha1b(X).
**
** sha1(X) returns a lower-case hexadecimal rendering of the SHA1 hash
** of the argument X.  If X is a BLOB, it is hashed as is.  For all other
** types of input, X is converted into a UTF-8 string and the string
** is hashed without the trailing 0x00 terminator.  The hash of a NULL
** value is NULL.
**
** sha1b(X) is the same except that it returns a 20-byte BLOB containing
** the binary hash instead of a hexadecimal string.
*/
static void sha1Func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  SHA1Context cx;
  int eType = sqlite3_value_type(argv[0]);
  int nByte = sqlite3_value_bytes(argv[0]);
  const unsigned char *pData;
  char zOut[44];

  assert( argc==1 );
  if( eType==SQLITE_NULL ) return;
  hash_init(&cx);
  if( eType==SQLITE_BLOB ){
    pData = (const unsigned char*)sqlite3_value_blob(argv[0]);
  }else{
    pData = (const unsigned char*)sqlite3_value_text(argv[0]);
  }
  if( pData==0 ) return;
  hash_step(&cx, pData, nByte);
  if( sqlite3_user_data(context)!=0 ){
    /* sha1b() - binary result */
    hash_finish(&cx, zOut, 1);
    sqlite3_result_blob(context, zOut, 20, SQLITE_TRANSIENT);
  }else{
    /* sha1() - hexadecimal text result */
    hash_finish(&cx, zOut, 0);
    sqlite3_result_text(context, zOut, 40, SQLITE_TRANSIENT);
  }
}

/*
** Implementation of the sha1_query(SQL) function.
**
** This function compiles and runs the SQL statement(s) given in the
** argument. The results are hashed using SHA1 and that hash is returned.
**
** The original SQL text is included as part of the hash.
**
** The hash is not just a concatenation of the outputs.  Each query
** is delimited and each row and value within the query is delimited,
** with all values being marked with their datatypes.
*/
static void sha1QueryFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3 *db = sqlite3_context_db_handle(context);
  const char *zSql = (const char*)sqlite3_value_text(argv[0]);
  sqlite3_stmt *pStmt = 0;
  int nCol;                   /* Number of columns in the result set */
  int i;                      /* Loop counter */
  int rc;
  int n;
  const char *z;
  SHA1Context cx;
  char zOut[44];

  assert( argc==1 );
  if( zSql==0 ) return;
  hash_init(&cx);
  while( zSql[0] ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zSql);
    if( rc ){
      char *zMsg = sqlite3_mprintf("error SQL statement [%s]: %s",
                                   zSql, sqlite3_errmsg(db));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    if( !sqlite3_stmt_readonly(pStmt) ){
      char *zMsg = sqlite3_mprintf("non-query: [%s]", sqlite3_sql(pStmt));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    nCol = sqlite3_column_count(pStmt);
    z = sqlite3_sql(pStmt);
    if( z==0 ) z = "";
    n = (int)strlen(z);
    hash_step_vformat(&cx,"S%d:",n);
    hash_step(&cx,(unsigned char*)z,n);

    /* Compute a hash over the result of the query */
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      hash_step(&cx,(const unsigned char*)"R",1);
      for(i=0; i<nCol; i++){
        switch( sqlite3_column_type(pStmt,i) ){
          case SQLITE_NULL: {
            hash_step(&cx, (const unsigned char*)"N",1);
            break;
          }
          case SQLITE_INTEGER: {
            sqlite3_uint64 u;
            int j;
            unsigned char x[9];
            sqlite3_int64 v = sqlite3_column_int64(pStmt,i);
            memcpy(&u, &v, 8);
            for(j=8; j>=1; j--){
              x[j] = u & 0xff;
              u >>= 8;
            }
            x[0] = 'I';
            hash_step(&cx, x, 9);
            break;
          }
          case SQLITE_FLOAT: {
            sqlite3_uint64 u;
            int j;
            unsigned char x[9];
            double r = sqlite3_column_double(pStmt,i);
            memcpy(&u, &r, 8);
            for(j=8; j>=1; j--){
              x[j] = u & 0xff;
              u >>= 8;
            }
            x[0] = 'F';
            hash_step(&cx,x,9);
            break;
          }
          case SQLITE_TEXT: {
            int n2 = sqlite3_column_bytes(pStmt, i);
            const unsigned char *z2 = sqlite3_column_text(pStmt, i);
            hash_step_vformat(&cx,"T%d:",n2);
            hash_step(&cx, z2, n2);
            break;
          }
          case SQLITE_BLOB: {
            int n2 = sqlite3_column_bytes(pStmt, i);
            const unsigned char *z2 = sqlite3_column_blob(pStmt, i);
            hash_step_vformat(&cx,"B%d:",n2);
            hash_step(&cx, z2, n2);
            break;
          }
        }
      }
    }
    sqlite3_finalize(pStmt);
  }
  hash_finish(&cx, zOut, 0);
  sqlite3_result_text(context, zOut, 40, SQLITE_TRANSIENT);
}


#ifdef _WIN32

#endif
int sqlite3_sha_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  static int one = 1;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sha1", 1, 
                       SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                                0, sha1Func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha1b", 1, 
                       SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                          (void*)&one, sha1Func, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha1_query", 1, 
                                 SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                                 sha1QueryFunc, 0, 0);
  }
  return rc;
}
#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  return sqlite3_sha_init(db, pzErrMsg, pApi);
}
#endif

/************************* End ext/misc/sha1.c ********************/
/************************* Begin ext/misc/uint.c ******************/
/*
** 2020-04-14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements the UINT collating sequence.
**
** UINT works like BINARY for text, except that embedded strings
** of digits compare in numeric order.
**
**     *   Leading zeros are handled properly, in the sense that
**         they do not mess of the magnitude comparison of embedded
**         strings of digits.  "x00123y" is equal to "x123y".
**
**     *   Only unsigned integers are recognized.  Plus and minus
**         signs are ignored.  Decimal points and exponential notation
**         are ignored.
**
**     *   Embedded integers can be of arbitrary length.  Comparison
**         is *not* limited integers that can be expressed as a
**         64-bit machine integer.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>

/*
** Compare text in lexicographic order, except strings of digits
** compare in numeric order.
*/
static int uintCollFunc(
  void *notUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const unsigned char *zA = (const unsigned char*)pKey1;
  const unsigned char *zB = (const unsigned char*)pKey2;
  int i=0, j=0, x;
  (void)notUsed;
  while( i<nKey1 && j<nKey2 ){
    x = zA[i] - zB[j];
    if( isdigit(zA[i]) ){
      int k;
      if( !isdigit(zB[j]) ) return x;
      while( i<nKey1 && zA[i]=='0' ){ i++; }
      while( j<nKey2 && zB[j]=='0' ){ j++; }
      k = 0;
      while( i+k<nKey1 && isdigit(zA[i+k])
             && j+k<nKey2 && isdigit(zB[j+k]) ){
        k++;
      }
      if( i+k<nKey1 && isdigit(zA[i+k]) ){
        return +1;
      }else if( j+k<nKey2 && isdigit(zB[j+k]) ){
        return -1;
      }else{
        x = memcmp(zA+i, zB+j, k);
        if( x ) return x;
        i += k;
        j += k;
      }
    }else if( x ){
      return x;
    }else{
      i++;
      j++;
    }
  }
  return (nKey1 - i) - (nKey2 - j);
}

#ifdef _WIN32

#endif
int sqlite3_uint_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  return sqlite3_create_collation(db, "uint", SQLITE_UTF8, 0, uintCollFunc);
}

/************************* End ext/misc/uint.c ********************/
/************************* Begin ext/misc/decimal.c ******************/
/*
** 2020-06-22
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** Routines to implement arbitrary-precision decimal math.
**
** The focus here is on simplicity and correctness, not performance.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>

/* Mark a function parameter as unused, to suppress nuisance compiler
** warnings. */
#ifndef UNUSED_PARAMETER
# define UNUSED_PARAMETER(X)  (void)(X)
#endif

#ifndef IsSpace
#define IsSpace(X)  isspace((unsigned char)X)
#endif

#ifndef SQLITE_DECIMAL_MAX_DIGIT
# define SQLITE_DECIMAL_MAX_DIGIT 10000000
#endif

/* A decimal object */
typedef struct Decimal Decimal;
struct Decimal {
  char sign;        /* 0 for positive, 1 for negative */
  char oom;         /* True if an OOM is encountered */
  char isNull;      /* True if holds a NULL rather than a number */
  char isInit;      /* True upon initialization */
  int nDigit;       /* Total number of digits */
  int nFrac;        /* Number of digits to the right of the decimal point */
  signed char *a;   /* Array of digits.  Most significant first. */
};

/*
** Release memory held by a Decimal, but do not free the object itself.
*/
static void decimal_clear(Decimal *p){
  sqlite3_free(p->a);
}

/*
** Destroy a Decimal object
*/
static void decimal_free(Decimal *p){
  if( p ){
    decimal_clear(p);
    sqlite3_free(p);
  }
}

/*
** Allocate a new Decimal object initialized to the text in zIn[].
** Return NULL if any kind of error occurs.
*/
static Decimal *decimalNewFromText(const char *zIn, int n){
  Decimal *p = 0;
  int i;
  int iExp = 0;

  if( zIn==0 ) goto new_from_text_failed;
  p = sqlite3_malloc64( sizeof(*p) );
  if( p==0 ) goto new_from_text_failed;
  p->sign = 0;
  p->oom = 0;
  p->isInit = 1;
  p->isNull = 0;
  p->nDigit = 0;
  p->nFrac = 0;
  p->a = sqlite3_malloc64( n+1 );
  if( p->a==0 ) goto new_from_text_failed;
  for(i=0; IsSpace(zIn[i]); i++){}
  if( zIn[i]=='-' ){
    p->sign = 1;
    i++;
  }else if( zIn[i]=='+' ){
    i++;
  }
  while( i<n && zIn[i]=='0' ) i++;
  while( i<n ){
    char c = zIn[i];
    if( c>='0' && c<='9' ){
      p->a[p->nDigit++] = c - '0';
    }else if( c=='.' ){
      p->nFrac = p->nDigit + 1;
    }else if( c=='e' || c=='E' ){
      int j = i+1;
      int neg = 0;
      if( j>=n ) break;
      if( zIn[j]=='-' ){
        neg = 1;
        j++;
      }else if( zIn[j]=='+' ){
        j++;
      }
      while( j<n && iExp<1000000 ){
        if( zIn[j]>='0' && zIn[j]<='9' ){
          iExp = iExp*10 + zIn[j] - '0';
        }
        j++;
      }
      if( neg ) iExp = -iExp;
      break;
    }
    i++;
  }
  if( p->nFrac ){
    p->nFrac = p->nDigit - (p->nFrac - 1);
  }
  if( iExp>0 ){
    if( p->nFrac>0 ){
      if( iExp<=p->nFrac ){
        p->nFrac -= iExp;
        iExp = 0;
      }else{
        iExp -= p->nFrac;
        p->nFrac = 0;
      }
    }
    if( iExp>0 ){   
      signed char *a = sqlite3_realloc64(p->a, (sqlite3_int64)p->nDigit
                                     + (sqlite3_int64)iExp + 1 );
      if( a==0 ) goto new_from_text_failed;
      p->a = a;
      memset(p->a+p->nDigit, 0, iExp);
      p->nDigit += iExp;
    }
  }else if( iExp<0 ){
    int nExtra;
    iExp = -iExp;
    nExtra = p->nDigit - p->nFrac - 1;
    if( nExtra ){
      if( nExtra>=iExp ){
        p->nFrac += iExp;
        iExp  = 0;
      }else{
        iExp -= nExtra;
        p->nFrac = p->nDigit - 1;
      }
    }
    if( iExp>0 ){
      signed char *a = sqlite3_realloc64(p->a, (sqlite3_int64)p->nDigit
                                     + (sqlite3_int64)iExp + 1 );
      if( a==0 ) goto new_from_text_failed;
      p->a = a;
      memmove(p->a+iExp, p->a, p->nDigit);
      memset(p->a, 0, iExp);
      p->nDigit += iExp;
      p->nFrac += iExp;
    }
  }
  if( p->sign ){
    for(i=0; i<p->nDigit && p->a[i]==0; i++){}
    if( i>=p->nDigit ) p->sign = 0;
  }
  if( p->nDigit>SQLITE_DECIMAL_MAX_DIGIT ) goto new_from_text_failed;
  return p;

new_from_text_failed:
  if( p ){
    if( p->a ) sqlite3_free(p->a);
    sqlite3_free(p);
  }
  return 0;
}

/* Forward reference */
static Decimal *decimalFromDouble(double);

/*
** Allocate a new Decimal object from an sqlite3_value.  Return a pointer
** to the new object, or NULL if there is an error.  If the pCtx argument
** is not NULL, then errors are reported on it as well.
**
** If the pIn argument is SQLITE_TEXT or SQLITE_INTEGER, it is converted
** directly into a Decimal.  For SQLITE_FLOAT or for SQLITE_BLOB of length
** 8 bytes, the resulting double value is expanded into its decimal equivalent.
** If pIn is NULL or if it is a BLOB that is not exactly 8 bytes in length,
** then NULL is returned.
*/
static Decimal *decimal_new(
  sqlite3_context *pCtx,       /* Report error here, if not null */
  sqlite3_value *pIn,          /* Construct the decimal object from this */
  int bTextOnly                /* Always interpret pIn as text if true */
){
  Decimal *p = 0;
  int eType = sqlite3_value_type(pIn);
  if( bTextOnly && (eType==SQLITE_FLOAT || eType==SQLITE_BLOB) ){
    eType = SQLITE_TEXT;
  }
  switch( eType ){
    case SQLITE_TEXT:
    case SQLITE_INTEGER: {
      const char *zIn = (const char*)sqlite3_value_text(pIn);
      int n = sqlite3_value_bytes(pIn);
      p = decimalNewFromText(zIn, n);
      if( p==0 ) goto new_failed;
      break;
    }

    case SQLITE_FLOAT: {
      p = decimalFromDouble(sqlite3_value_double(pIn));
      break;
    }

    case SQLITE_BLOB: {
      const unsigned char *x;
      unsigned int i;
      sqlite3_uint64 v = 0;
      double r;

      if( sqlite3_value_bytes(pIn)!=sizeof(r) ) break;
      x = sqlite3_value_blob(pIn);
      for(i=0; i<sizeof(r); i++){
        v = (v<<8) | x[i];
      }
      memcpy(&r, &v, sizeof(r));
      p = decimalFromDouble(r);
      break;
    }

    case SQLITE_NULL: {
      break;
    }
  }
  return p;

new_failed:
  if( pCtx ) sqlite3_result_error_nomem(pCtx);
  sqlite3_free(p);
  return 0;
}

/*
** Make the given Decimal the result.
*/
static void decimal_result(sqlite3_context *pCtx, Decimal *p){
  char *z;
  int i, j;
  int n;
  if( p==0 || p->oom ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( p->isNull ){
    sqlite3_result_null(pCtx);
    return;
  }
  z = sqlite3_malloc64( (sqlite3_int64)p->nDigit+4 );
  if( z==0 ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  i = 0;
  if( p->nDigit==0 || (p->nDigit==1 && p->a[0]==0) ){
    p->sign = 0;
  }
  if( p->sign ){
    z[0] = '-';
    i = 1;
  }
  n = p->nDigit - p->nFrac;
  if( n<=0 ){
    z[i++] = '0';
  }
  j = 0;
  while( n>1 && p->a[j]==0 ){
    j++;
    n--;
  }
  while( n>0  ){
    z[i++] = p->a[j] + '0';
    j++;
    n--;
  }
  if( p->nFrac ){
    z[i++] = '.';
    do{
      z[i++] = p->a[j] + '0';
      j++;
    }while( j<p->nDigit );
  }
  z[i] = 0;
  sqlite3_result_text(pCtx, z, i, sqlite3_free);
}

/*
** Round a decimal value to N significant digits.  N must be positive.
*/
static void decimal_round(Decimal *p, int N){
  int i;
  int nZero;
  if( N<1 ) return;
  if( p==0 ) return;
  if( p->nDigit<=N ) return;
  for(nZero=0; nZero<p->nDigit && p->a[nZero]==0; nZero++){}
  N += nZero;
  if( p->nDigit<=N ) return;
  if( p->a[N]>4 ){
    p->a[N-1]++;
    for(i=N-1; i>0 && p->a[i]>9; i--){
      p->a[i] = 0;
      p->a[i-1]++;
    }
    if( p->a[0]>9 ){
      p->a[0] = 1;
      p->nFrac--;
    }
  }
  memset(&p->a[N], 0, p->nDigit - N);
}

/*
** Make the given Decimal the result in an format similar to  '%+#e'.
** In other words, show exponential notation with leading and trailing
** zeros omitted.
*/
static void decimal_result_sci(sqlite3_context *pCtx, Decimal *p, int N){
  char *z;       /* The output buffer */
  int i;         /* Loop counter */
  int nZero;     /* Number of leading zeros */
  int nDigit;    /* Number of digits not counting trailing zeros */
  int nFrac;     /* Digits to the right of the decimal point */
  int exp;       /* Exponent value */
  signed char zero;     /* Zero value */
  signed char *a;       /* Array of digits */

  if( p==0 || p->oom ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( p->isNull ){
    sqlite3_result_null(pCtx);
    return;
  }
  if( N<1 ) N = 0;
  for(nDigit=p->nDigit; nDigit>N && p->a[nDigit-1]==0; nDigit--){}
  for(nZero=0; nZero<nDigit && p->a[nZero]==0; nZero++){}
  nFrac = p->nFrac + (nDigit - p->nDigit);
  nDigit -= nZero;
  z = sqlite3_malloc64( (sqlite3_int64)nDigit+20 );
  if( z==0 ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( nDigit==0 ){
    zero = 0;
    a = &zero;
    nDigit = 1;
    nFrac = 0;
  }else{
    a = &p->a[nZero];
  }
  if( p->sign && nDigit>0 ){
    z[0] = '-';
  }else{
    z[0] = '+';
  }
  z[1] = a[0]+'0';
  z[2] = '.';
  if( nDigit==1 ){
    z[3] = '0';
    i = 4;
  }else{
    for(i=1; i<nDigit; i++){
      z[2+i] = a[i]+'0';
    }
    i = nDigit+2;
  }
  exp = nDigit - nFrac - 1;
  sqlite3_snprintf(nDigit+20-i, &z[i], "e%+03d", exp);
  sqlite3_result_text(pCtx, z, -1, sqlite3_free);
}

/*
** Compare to Decimal objects.  Return negative, 0, or positive if the
** first object is less than, equal to, or greater than the second.
**
** Preconditions for this routine:
**
**    pA!=0
**    pA->isNull==0
**    pB!=0
**    pB->isNull==0
*/
static int decimal_cmp(Decimal *pA, Decimal *pB){
  int nASig, nBSig, rc, n;
  while( pA->nFrac>0 && pA->a[pA->nDigit-1]==0 ){
    pA->nDigit--;
    pA->nFrac--;
  }
  while( pB->nFrac>0 && pB->a[pB->nDigit-1]==0 ){
    pB->nDigit--;
    pB->nFrac--;
  }
  if( pA->sign!=pB->sign ){
    return pA->sign ? -1 : +1;
  }
  if( pA->sign ){
    Decimal *pTemp = pA;
    pA = pB;
    pB = pTemp;
  }
  nASig = pA->nDigit - pA->nFrac;
  nBSig = pB->nDigit - pB->nFrac;
  if( nASig!=nBSig ){
    return nASig - nBSig;
  }
  n = pA->nDigit;
  if( n>pB->nDigit ) n = pB->nDigit;
  rc = memcmp(pA->a, pB->a, n);
  if( rc==0 ){
    rc = pA->nDigit - pB->nDigit;
  }
  return rc;
}

/*
** SQL Function:   decimal_cmp(X, Y)
**
** Return negative, zero, or positive if X is less then, equal to, or
** greater than Y.
*/
static void decimalCmpFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = 0, *pB = 0;
  int rc;

  UNUSED_PARAMETER(argc);
  pA = decimal_new(context, argv[0], 1);
  if( pA==0 || pA->isNull ) goto cmp_done;
  pB = decimal_new(context, argv[1], 1);
  if( pB==0 || pB->isNull ) goto cmp_done;
  rc = decimal_cmp(pA, pB);
  if( rc<0 ) rc = -1;
  else if( rc>0 ) rc = +1;
  sqlite3_result_int(context, rc);
cmp_done:
  decimal_free(pA);
  decimal_free(pB);
}

/*
** Expand the Decimal so that it has a least nDigit digits and nFrac
** digits to the right of the decimal point.
*/
static void decimal_expand(Decimal *p, int nDigit, int nFrac){
  int nAddSig;
  int nAddFrac;
  signed char *a;
  if( p==0 ) return;
  nAddFrac = nFrac - p->nFrac;
  nAddSig = (nDigit - p->nDigit) - nAddFrac;
  if( nAddFrac==0 && nAddSig==0 ) return;
  if( nDigit+1>SQLITE_DECIMAL_MAX_DIGIT ){ p->oom = 1; return; }
  a = sqlite3_realloc64(p->a, nDigit+1);
  if( a==0 ){
    p->oom = 1;
    return;
  }
  p->a = a;
  if( nAddSig ){
    memmove(p->a+nAddSig, p->a, p->nDigit);
    memset(p->a, 0, nAddSig);
    p->nDigit += nAddSig;
  }
  if( nAddFrac ){
    memset(p->a+p->nDigit, 0, nAddFrac);
    p->nDigit += nAddFrac;
    p->nFrac += nAddFrac;
  }
}

/*
** Add the value pB into pA.   A := A + B.
**
** Both pA and pB might become denormalized by this routine.
*/
static void decimal_add(Decimal *pA, Decimal *pB){
  int nSig, nFrac, nDigit;
  int i, rc;
  if( pA==0 ){
    return;
  }
  if( pA->oom || pB==0 || pB->oom ){
    pA->oom = 1;
    return;
  }
  if( pA->isNull || pB->isNull ){
    pA->isNull = 1;
    return;
  }
  nSig = pA->nDigit - pA->nFrac;
  if( nSig && pA->a[0]==0 ) nSig--;
  if( nSig<pB->nDigit-pB->nFrac ){
    nSig = pB->nDigit - pB->nFrac;
  }
  nFrac = pA->nFrac;
  if( nFrac<pB->nFrac ) nFrac = pB->nFrac;
  nDigit = nSig + nFrac + 1;
  decimal_expand(pA, nDigit, nFrac);
  decimal_expand(pB, nDigit, nFrac);
  if( pA->oom || pB->oom ){
    pA->oom = 1;
  }else{
    if( pA->sign==pB->sign ){
      int carry = 0;
      for(i=nDigit-1; i>=0; i--){
        int x = pA->a[i] + pB->a[i] + carry;
        if( x>=10 ){
          carry = 1;
          pA->a[i] = x - 10;
        }else{
          carry = 0;
          pA->a[i] = x;
        }
      }
    }else{
      signed char *aA, *aB;
      int borrow = 0;
      rc = memcmp(pA->a, pB->a, nDigit);
      if( rc<0 ){
        aA = pB->a;
        aB = pA->a;
        pA->sign = !pA->sign;
      }else{
        aA = pA->a;
        aB = pB->a;
      }
      for(i=nDigit-1; i>=0; i--){
        int x = aA[i] - aB[i] - borrow;
        if( x<0 ){
          pA->a[i] = x+10;
          borrow = 1;
        }else{
          pA->a[i] = x;
          borrow = 0;
        }
      }
    }
  }
}

/*
** Multiply A by B.   A := A * B
**
** All significant digits after the decimal point are retained.
** Trailing zeros after the decimal point are omitted as long as
** the number of digits after the decimal point is no less than
** either the number of digits in either input.
*/
static void decimalMul(Decimal *pA, Decimal *pB){
  signed char *acc = 0;
  int i, j, k;
  int minFrac;
  sqlite3_int64 sumDigit;

  if( pA==0 || pA->oom || pA->isNull
   || pB==0 || pB->oom || pB->isNull 
  ){
    goto mul_end;
  }
  sumDigit = pA->nDigit;
  sumDigit += pB->nDigit;
  sumDigit += 2;
  if( sumDigit>SQLITE_DECIMAL_MAX_DIGIT ){ pA->oom = 1; return; }
  acc = sqlite3_malloc64( sumDigit );
  if( acc==0 ){
    pA->oom = 1;
    goto mul_end;
  }
  memset(acc, 0, pA->nDigit + pB->nDigit + 2);
  minFrac = pA->nFrac;
  if( pB->nFrac<minFrac ) minFrac = pB->nFrac;
  for(i=pA->nDigit-1; i>=0; i--){
    signed char f = pA->a[i];
    int carry = 0, x;
    for(j=pB->nDigit-1, k=i+j+3; j>=0; j--, k--){
      x = acc[k] + f*pB->a[j] + carry;
      acc[k] = x%10;
      carry = x/10;
    }
    x = acc[k] + carry;
    acc[k] = x%10;
    acc[k-1] += x/10;
  }
  sqlite3_free(pA->a);
  pA->a = acc;
  acc = 0;
  pA->nDigit += pB->nDigit + 2;
  pA->nFrac += pB->nFrac;
  pA->sign ^= pB->sign;
  while( pA->nFrac>minFrac && pA->a[pA->nDigit-1]==0 ){
    pA->nFrac--;
    pA->nDigit--;
  }

mul_end:
  sqlite3_free(acc);
}

/*
** Create a new Decimal object that contains an integer power of 2.
*/
static Decimal *decimalPow2(int N){
  Decimal *pA = 0;      /* The result to be returned */
  Decimal *pX = 0;      /* Multiplier */
  if( N<-20000 || N>20000 ) goto pow2_fault;
  pA = decimalNewFromText("1.0", 3);
  if( pA==0 || pA->oom ) goto pow2_fault;
  if( N==0 ) return pA;
  if( N>0 ){
    pX = decimalNewFromText("2.0", 3);
  }else{
    N = -N;
    pX = decimalNewFromText("0.5", 3);
  }
  if( pX==0 || pX->oom ) goto pow2_fault;
  while( 1 /* Exit by break */ ){
    if( N & 1 ){
      decimalMul(pA, pX);
      if( pA->oom ) goto pow2_fault;
    }
    N >>= 1;
    if( N==0 ) break;
    decimalMul(pX, pX);
  }
  decimal_free(pX);
  return pA;

pow2_fault:
  decimal_free(pA);
  decimal_free(pX);
  return 0;
}

/*
** Use an IEEE754 binary64 ("double") to generate a new Decimal object.
*/
static Decimal *decimalFromDouble(double r){
  sqlite3_int64 m, a;
  int e;
  int isNeg;
  Decimal *pA;
  Decimal *pX;
  char zNum[100];
  if( r<0.0 ){
    isNeg = 1;
    r = -r;
  }else{
    isNeg = 0;
  }
  memcpy(&a,&r,sizeof(a));
  if( a==0 || a==(sqlite3_int64)0x8000000000000000LL){
    e = 0;
    m = 0;
  }else{
    e = a>>52;
    m = a & ((((sqlite3_int64)1)<<52)-1);
    if( e==0 ){
      m <<= 1;
    }else{
      m |= ((sqlite3_int64)1)<<52;
    }
    while( e<1075 && m>0 && (m&1)==0 ){
      m >>= 1;
      e++;
    }
    if( isNeg ) m = -m;
    e = e - 1075;
    if( e>971 ){
      return 0;  /* A NaN or an Infinity */
    }
  }

  /* At this point m is the integer significand and e is the exponent */
  sqlite3_snprintf(sizeof(zNum), zNum, "%lld", m);
  pA = decimalNewFromText(zNum, (int)strlen(zNum));
  pX = decimalPow2(e);
  decimalMul(pA, pX);
  decimal_free(pX);
  return pA;
}

/*
** SQL Function:   decimal(X)
** OR:             decimal_exp(X)
**
** Convert input X into decimal and then back into text.
**
** If X is originally a float, then a full decimal expansion of that floating
** point value is done.  Or if X is an 8-byte blob, it is interpreted
** as a float and similarly expanded.
**
** The decimal_exp(X) function returns the result in exponential notation.
** decimal(X) returns a complete decimal, without the e+NNN at the end.
*/
static void decimalFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *p =  decimal_new(context, argv[0], 0);
  int N;
  if( argc==2 ){
    N = sqlite3_value_int(argv[1]);
    if( N>0 ) decimal_round(p, N);
  }else{
    N = 0;
  }
  if( p ){
    if( sqlite3_user_data(context)!=0 ){
      decimal_result_sci(context, p, N);
    }else{
      decimal_result(context, p);
    }
    decimal_free(p);
  }
}

/*
** Compare text in decimal order.
*/
static int decimalCollFunc(
  void *notUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const unsigned char *zA = (const unsigned char*)pKey1;
  const unsigned char *zB = (const unsigned char*)pKey2;
  Decimal *pA = decimalNewFromText((const char*)zA, nKey1);
  Decimal *pB = decimalNewFromText((const char*)zB, nKey2);
  int rc;
  UNUSED_PARAMETER(notUsed);
  if( pA==0 || pB==0 ){
    rc = 0;
  }else{
    rc = decimal_cmp(pA, pB);
  }
  decimal_free(pA);
  decimal_free(pB);
  return rc;
}


/*
** SQL Function:   decimal_add(X, Y)
**                 decimal_sub(X, Y)
**
** Return the sum or difference of X and Y.
*/
static void decimalAddFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = decimal_new(context, argv[0], 1);
  Decimal *pB = decimal_new(context, argv[1], 1);
  UNUSED_PARAMETER(argc);
  decimal_add(pA, pB);
  decimal_result(context, pA);
  decimal_free(pA);
  decimal_free(pB);
}
static void decimalSubFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = decimal_new(context, argv[0], 1);
  Decimal *pB = decimal_new(context, argv[1], 1);
  UNUSED_PARAMETER(argc);
  if( pB ){
    pB->sign = !pB->sign;
    decimal_add(pA, pB);
    decimal_result(context, pA);
  }
  decimal_free(pA);
  decimal_free(pB);
}

/* Aggregate function:   decimal_sum(X)
**
** Works like sum() except that it uses decimal arithmetic for unlimited
** precision.
*/
static void decimalSumStep(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *p;
  Decimal *pArg;
  UNUSED_PARAMETER(argc);
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( !p->isInit ){
    p->isInit = 1;
    p->a = sqlite3_malloc64(2);
    if( p->a==0 ){
      p->oom = 1;
    }else{
      p->a[0] = 0;
    }
    p->nDigit = 1;
    p->nFrac = 0;
  }
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  pArg = decimal_new(context, argv[0], 1);
  decimal_add(p, pArg);
  decimal_free(pArg);
}
static void decimalSumInverse(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *p;
  Decimal *pArg;
  UNUSED_PARAMETER(argc);
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  pArg = decimal_new(context, argv[0], 1);
  if( pArg ) pArg->sign = !pArg->sign;
  decimal_add(p, pArg);
  decimal_free(pArg);
}
static void decimalSumValue(sqlite3_context *context){
  Decimal *p = sqlite3_aggregate_context(context, 0);
  if( p==0 ) return;
  decimal_result(context, p);
}
static void decimalSumFinalize(sqlite3_context *context){
  Decimal *p = sqlite3_aggregate_context(context, 0);
  if( p==0 ) return;
  decimal_result(context, p);
  decimal_clear(p);
}

/*
** SQL Function:   decimal_mul(X, Y)
**
** Return the product of X and Y.
*/
static void decimalMulFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = decimal_new(context, argv[0], 1);
  Decimal *pB = decimal_new(context, argv[1], 1);
  UNUSED_PARAMETER(argc);
  if( pA==0 || pA->oom || pA->isNull
   || pB==0 || pB->oom || pB->isNull 
  ){
    goto mul_end;
  }
  decimalMul(pA, pB);
  if( pA->oom ){
    goto mul_end;
  }
  decimal_result(context, pA);

mul_end:
  decimal_free(pA);
  decimal_free(pB);
}

/*
** SQL Function:   decimal_pow2(N)
**
** Return the N-th power of 2.  N must be an integer.
*/
static void decimalPow2Func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_INTEGER ){
    Decimal *pA = decimalPow2(sqlite3_value_int(argv[0]));
    decimal_result_sci(context, pA, 0);
    decimal_free(pA);
  }
}

#ifdef _WIN32

#endif
int sqlite3_decimal_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  static const struct {
    const char *zFuncName;
    int nArg;
    int iArg;
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {
    { "decimal",       1, 0,  decimalFunc        },
    { "decimal",       2, 0,  decimalFunc        },
    { "decimal_exp",   1, 1,  decimalFunc        },
    { "decimal_exp",   2, 1,  decimalFunc        },
    { "decimal_cmp",   2, 0,  decimalCmpFunc     },
    { "decimal_add",   2, 0,  decimalAddFunc     },
    { "decimal_sub",   2, 0,  decimalSubFunc     },
    { "decimal_mul",   2, 0,  decimalMulFunc     },
    { "decimal_pow2",  1, 0,  decimalPow2Func    },
  };
  unsigned int i;
  (void)pzErrMsg;  /* Unused parameter */

  SQLITE_EXTENSION_INIT2(pApi);

  for(i=0; i<(int)(sizeof(aFunc)/sizeof(aFunc[0])) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zFuncName, aFunc[i].nArg,
                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                   aFunc[i].iArg ? db : 0, aFunc[i].xFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_window_function(db, "decimal_sum", 1,
                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC, 0,
                   decimalSumStep, decimalSumFinalize,
                   decimalSumValue, decimalSumInverse, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_collation(db, "decimal", SQLITE_UTF8,
                                  0, decimalCollFunc);
  }
  return rc;
}

/************************* End ext/misc/decimal.c ********************/
/************************* Begin ext/misc/base64.c ******************/
/*
** 2022-11-18
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This is a SQLite extension for converting in either direction
** between a (binary) blob and base64 text. Base64 can transit a
** sane USASCII channel unmolested. It also plays nicely in CSV or
** written as TCL brace-enclosed literals or SQL string literals,
** and can be used unmodified in XML-like documents.
**
** This is an independent implementation of conversions specified in
** RFC 4648, done on the above date by the author (Larry Brasfield)
** who thereby has the right to put this into the public domain.
**
** The conversions meet RFC 4648 requirements, provided that this
** C source specifies that line-feeds are included in the encoded
** data to limit visible line lengths to 72 characters and to
** terminate any encoded blob having non-zero length.
**
** Length limitations are not imposed except that the runtime
** SQLite string or blob length limits are respected. Otherwise,
** any length binary sequence can be represented and recovered.
** Generated base64 sequences, with their line-feeds included,
** can be concatenated; the result converted back to binary will
** be the concatenation of the represented binary sequences.
**
** This SQLite3 extension creates a function, base64(x), which
** either: converts text x containing base64 to a returned blob;
** or converts a blob x to returned text containing base64. An
** error will be thrown for other input argument types.
**
** This code relies on UTF-8 encoding only with respect to the
** meaning of the first 128 (7-bit) codes matching that of USASCII.
** It will fail miserably if somehow made to try to convert EBCDIC.
** Because it is table-driven, it could be enhanced to handle that,
** but the world and SQLite have moved on from that anachronism.
**
** To build the extension:
** Set shell variable SQDIR=<your favorite SQLite checkout directory>
** *Nix: gcc -O2 -shared -I$SQDIR -fPIC -o base64.so base64.c
** OSX: gcc -O2 -dynamiclib -fPIC -I$SQDIR -o base64.dylib base64.c
** Win32: gcc -O2 -shared -I%SQDIR% -o base64.dll base64.c
** Win32: cl /Os -I%SQDIR% base64.c -link -dll -out:base64.dll
*/

#include <assert.h>

/* #include "sqlite3ext.h" */

#ifndef deliberate_fall_through
/* Quiet some compilers about some of our intentional code. */
# if GCC_VERSION>=7000000
#  define deliberate_fall_through __attribute__((fallthrough));
# else
#  define deliberate_fall_through
# endif
#endif

SQLITE_EXTENSION_INIT1;

#define PC 0x80 /* pad character */
#define WS 0x81 /* whitespace */
#define ND 0x82 /* Not above or digit-value */
#define PAD_CHAR '='

#ifndef U8_TYPEDEF
/* typedef unsigned char u8; */
#define U8_TYPEDEF
#endif

/* Decoding table, ASCII (7-bit) value to base 64 digit value or other */
static const u8 b64DigitValues[128] = {
  /*                             HT LF VT  FF CR       */
    ND,ND,ND,ND, ND,ND,ND,ND, ND,WS,WS,WS, WS,WS,ND,ND,
  /*                                                US */
    ND,ND,ND,ND, ND,ND,ND,ND, ND,ND,ND,ND, ND,ND,ND,ND,
  /*sp                                  +            / */
    WS,ND,ND,ND, ND,ND,ND,ND, ND,ND,ND,62, ND,ND,ND,63,
  /* 0  1            5            9            =       */
    52,53,54,55, 56,57,58,59, 60,61,ND,ND, ND,PC,ND,ND,
  /*    A                                            O */
    ND, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
  /* P                               Z                 */
    15,16,17,18, 19,20,21,22, 23,24,25,ND, ND,ND,ND,ND,
  /*    a                                            o */
    ND,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
  /* p                               z                 */
    41,42,43,44, 45,46,47,48, 49,50,51,ND, ND,ND,ND,ND
};

static const char b64Numerals[64+1]
= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

#define BX_DV_PROTO(c) \
  ((((u8)(c))<0x80)? (u8)(b64DigitValues[(u8)(c)]) : 0x80)
#define IS_BX_DIGIT(bdp) (((u8)(bdp))<0x80)
#define IS_BX_WS(bdp) ((bdp)==WS)
#define IS_BX_PAD(bdp) ((bdp)==PC)
#define BX_NUMERAL(dv) (b64Numerals[(u8)(dv)])
/* Width of base64 lines. Should be an integer multiple of 4. */
#define B64_DARK_MAX 72

/* Encode a byte buffer into base64 text with linefeeds appended to limit
** encoded group lengths to B64_DARK_MAX or to terminate the last group.
*/
static char* toBase64( u8 *pIn, int nbIn, char *pOut ){
  int nCol = 0;
  while( nbIn >= 3 ){
    /* Do the bit-shuffle, exploiting unsigned input to avoid masking. */
    pOut[0] = BX_NUMERAL(pIn[0]>>2);
    pOut[1] = BX_NUMERAL(((pIn[0]<<4)|(pIn[1]>>4))&0x3f);
    pOut[2] = BX_NUMERAL(((pIn[1]&0xf)<<2)|(pIn[2]>>6));
    pOut[3] = BX_NUMERAL(pIn[2]&0x3f);
    pOut += 4;
    nbIn -= 3;
    pIn += 3;
    if( (nCol += 4)>=B64_DARK_MAX || nbIn<=0 ){
      *pOut++ = '\n';
      nCol = 0;
    }
  }
  if( nbIn > 0 ){
    signed char nco = nbIn+1;
    int nbe;
    unsigned long qv = *pIn++;
    for( nbe=1; nbe<3; ++nbe ){
      qv <<= 8;
      if( nbe<nbIn ) qv |= *pIn++;
    }
    for( nbe=3; nbe>=0; --nbe ){
      char ce = (nbe<nco)? BX_NUMERAL((u8)(qv & 0x3f)) : PAD_CHAR;
      qv >>= 6;
      pOut[nbe] = ce;
    }
    pOut += 4;
    *pOut++ = '\n';
  }
  *pOut = 0;
  return pOut;
}

/* Skip over text which is not base64 numeral(s). */
static char * skipNonB64( char *s, int nc ){
  char c;
  while( nc-- > 0 && (c = *s) && !IS_BX_DIGIT(BX_DV_PROTO(c)) ) ++s;
  return s;
}

/* Decode base64 text into a byte buffer. */
static u8* fromBase64( char *pIn, int ncIn, u8 *pOut ){
  if( ncIn>0 && pIn[ncIn-1]=='\n' ) --ncIn;
  while( ncIn>0 && *pIn!=PAD_CHAR ){
    static signed char nboi[] = { 0, 0, 1, 2, 3 };
    char *pUse = skipNonB64(pIn, ncIn);
    unsigned long qv = 0L;
    int nti, nbo, nac;
    ncIn -= (pUse - pIn);
    pIn = pUse;
    nti = (ncIn>4)? 4 : ncIn;
    ncIn -= nti;
    nbo = nboi[nti];
    if( nbo==0 ) break;
    for( nac=0; nac<4; ++nac ){
      char c = (nac<nti)? *pIn++ : b64Numerals[0];
      u8 bdp = BX_DV_PROTO(c);
      switch( bdp ){
      case ND:
        /*  Treat dark non-digits as pad, but they terminate decode too. */
        ncIn = 0;
        deliberate_fall_through; /* FALLTHRU */
      case WS:
        /* Treat whitespace as pad and terminate this group.*/
        nti = nac;
        deliberate_fall_through; /* FALLTHRU */
      case PC:
        bdp = 0;
        --nbo;
        deliberate_fall_through; /* FALLTHRU */
      default: /* bdp is the digit value. */
        qv = qv<<6 | bdp;
        break;
      }
    }
    switch( nbo ){
    case 3:
      pOut[2] = (qv) & 0xff;
      deliberate_fall_through; /* FALLTHRU */
    case 2:
      pOut[1] = (qv>>8) & 0xff;
      deliberate_fall_through; /* FALLTHRU */
    case 1:
      pOut[0] = (qv>>16) & 0xff;
      break;
    }
    pOut += nbo;
  }
  return pOut;
}

/* This function does the work for the SQLite base64(x) UDF. */
static void base64(sqlite3_context *context, int na, sqlite3_value *av[]){
  sqlite3_int64 nb;
  sqlite3_int64 nv = sqlite3_value_bytes(av[0]);
  sqlite3_int64 nc;
  int nvMax = sqlite3_limit(sqlite3_context_db_handle(context),
                            SQLITE_LIMIT_LENGTH, -1);
  char *cBuf;
  u8 *bBuf;
  assert(na==1);
  switch( sqlite3_value_type(av[0]) ){
  case SQLITE_BLOB:
    nb = nv;
    nc = 4*((nv+2)/3); /* quads needed */
    nc += (nc+(B64_DARK_MAX-1))/B64_DARK_MAX + 1; /* LFs and a 0-terminator */
    if( nvMax < nc ){
      sqlite3_result_error(context, "blob expanded to base64 too big", -1);
      return;
    }
    bBuf = (u8*)sqlite3_value_blob(av[0]);
    if( !bBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_text(context,"",-1,SQLITE_STATIC);
      break;
    }
    cBuf = sqlite3_malloc64(nc);
    if( !cBuf ) goto memFail;
    nc = (int)(toBase64(bBuf, nb, cBuf) - cBuf);
    sqlite3_result_text(context, cBuf, nc, sqlite3_free);
    break;
  case SQLITE_TEXT:
    nc = nv;
    nb = 3*((nv+3)/4); /* may overestimate due to LF and padding */
    if( nvMax < nb ){
      sqlite3_result_error(context, "blob from base64 may be too big", -1);
      return;
    }else if( nb<1 ){
      nb = 1;
    }
    cBuf = (char *)sqlite3_value_text(av[0]);
    if( !cBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_zeroblob(context, 0);
      break;
    }
    bBuf = sqlite3_malloc64(nb);
    if( !bBuf ) goto memFail;
    nb = (int)(fromBase64(cBuf, nc, bBuf) - bBuf);
    sqlite3_result_blob(context, bBuf, nb, sqlite3_free);
    break;
  default:
    sqlite3_result_error(context, "base64 accepts only blob or text", -1);
    return;
  }
  return;
 memFail:
  sqlite3_result_error(context, "base64 OOM", -1);
}

/*
** Establish linkage to running SQLite library.
*/
#ifndef SQLITE_SHELL_EXTFUNCS
#ifdef _WIN32

#endif
int sqlite3_base64_init
#else
static int sqlite3_base64_init
#endif
(sqlite3 *db, char **pzErr, const sqlite3_api_routines *pApi){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErr;
  return sqlite3_create_function
    (db, "base64", 1,
     SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS|SQLITE_DIRECTONLY|SQLITE_UTF8,
     0, base64, 0, 0);
}

/*
** Define some macros to allow this extension to be built into the shell
** conveniently, in conjunction with use of SQLITE_SHELL_EXTFUNCS. This
** allows shell.c, as distributed, to have this extension built in.
*/
#define BASE64_INIT(db) sqlite3_base64_init(db, 0, 0)
#define BASE64_EXPOSE(db, pzErr) /* Not needed, ..._init() does this. */

/************************* End ext/misc/base64.c ********************/
/************************* Begin ext/misc/base85.c ******************/
/*
** 2022-11-16
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This is a utility for converting binary to base85 or vice-versa.
** It can be built as a standalone program or an SQLite3 extension.
**
** Much like base64 representations, base85 can be sent through a
** sane USASCII channel unmolested. It also plays nicely in CSV or
** written as TCL brace-enclosed literals or SQL string literals.
** It is not suited for unmodified use in XML-like documents.
**
** The encoding used resembles Ascii85, but was devised by the author
** (Larry Brasfield) before Mozilla, Adobe, ZMODEM or other Ascii85
** variant sources existed, in the 1984 timeframe on a VAX mainframe.
** Further, this is an independent implementation of a base85 system.
** Hence, the author has rightfully put this into the public domain.
**
** Base85 numerals are taken from the set of 7-bit USASCII codes,
** excluding control characters and Space ! " ' ( ) { | } ~ Del
** in code order representing digit values 0 to 84 (base 10.)
**
** Groups of 4 bytes, interpreted as big-endian 32-bit values,
** are represented as 5-digit base85 numbers with MS to LS digit
** order. Groups of 1-3 bytes are represented with 2-4 digits,
** still big-endian but 8-24 bit values. (Using big-endian yields
** the simplest transition to byte groups smaller than 4 bytes.
** These byte groups can also be considered base-256 numbers.)
** Groups of 0 bytes are represented with 0 digits and vice-versa.
** No pad characters are used; Encoded base85 numeral sequence
** (aka "group") length maps 1-to-1 to the decoded binary length.
**
** Any character not in the base85 numeral set delimits groups.
** When base85 is streamed or stored in containers of indefinite
** size, newline is used to separate it into sub-sequences of no
** more than 80 digits so that fgets() can be used to read it.
**
** Length limitations are not imposed except that the runtime
** SQLite string or blob length limits are respected. Otherwise,
** any length binary sequence can be represented and recovered.
** Base85 sequences can be concatenated by separating them with
** a non-base85 character; the conversion to binary will then
** be the concatenation of the represented binary sequences.

** The standalone program either converts base85 on stdin to create
** a binary file or converts a binary file to base85 on stdout.
** Read or make it blurt its help for invocation details.
**
** The SQLite3 extension creates a function, base85(x), which will
** either convert text base85 to a blob or a blob to text base85
** and return the result (or throw an error for other types.)
** Unless built with OMIT_BASE85_CHECKER defined, it also creates a
** function, is_base85(t), which returns 1 iff the text t contains
** nothing other than base85 numerals and whitespace, or 0 otherwise.
**
** To build the extension:
** Set shell variable SQDIR=<your favorite SQLite checkout directory>
** and variable OPTS to -DOMIT_BASE85_CHECKER if is_base85() unwanted.
** *Nix: gcc -O2 -shared -I$SQDIR $OPTS -fPIC -o base85.so base85.c
** OSX: gcc -O2 -dynamiclib -fPIC -I$SQDIR $OPTS -o base85.dylib base85.c
** Win32: gcc -O2 -shared -I%SQDIR% %OPTS% -o base85.dll base85.c
** Win32: cl /Os -I%SQDIR% %OPTS% base85.c -link -dll -out:base85.dll
**
** To build the standalone program, define PP symbol BASE85_STANDALONE. Eg.
** *Nix or OSX: gcc -O2 -DBASE85_STANDALONE base85.c -o base85
** Win32: gcc -O2 -DBASE85_STANDALONE -o base85.exe base85.c
** Win32: cl /Os /MD -DBASE85_STANDALONE base85.c
*/

#include <stdio.h>
#include <memory.h>
#include <string.h>
#include <assert.h>
#ifndef OMIT_BASE85_CHECKER
# include <ctype.h>
#endif

#ifndef BASE85_STANDALONE

/* # include "sqlite3ext.h" */

SQLITE_EXTENSION_INIT1;

#else

# ifdef _WIN32
#  include <io.h>
#  include <fcntl.h>
# else
#  define setmode(fd,m)
# endif

static char *zHelp =
  "Usage: base85 <dirFlag> <binFile>\n"
  " <dirFlag> is either -r to read or -w to write <binFile>,\n"
  "   content to be converted to/from base85 on stdout/stdin.\n"
  " <binFile> names a binary file to be rendered or created.\n"
  "   Or, the name '-' refers to the stdin or stdout stream.\n"
  ;

static void sayHelp(){
  printf("%s", zHelp);
}
#endif

#ifndef U8_TYPEDEF
/* typedef unsigned char u8; */
#define U8_TYPEDEF
#endif

/* Classify c according to interval within USASCII set w.r.t. base85
 * Values of 1 and 3 are base85 numerals. Values of 0, 2, or 4 are not.
 */
#define B85_CLASS( c ) (((c)>='#')+((c)>'&')+((c)>='*')+((c)>'z'))

/* Provide digitValue to b85Numeral offset as a function of above class. */
static u8 b85_cOffset[] = { 0, '#', 0, '*'-4, 0 };
#define B85_DNOS( c ) b85_cOffset[B85_CLASS(c)]

/* Say whether c is a base85 numeral. */
#define IS_B85( c ) (B85_CLASS(c) & 1)

#if 0 /* Not used, */
static u8 base85DigitValue( char c ){
  u8 dv = (u8)(c - '#');
  if( dv>87 ) return 0xff;
  return (dv > 3)? dv-3 : dv;
}
#endif

/* Width of base64 lines. Should be an integer multiple of 5. */
#define B85_DARK_MAX 80


static char * skipNonB85( char *s, int nc ){
  char c;
  while( nc-- > 0 && (c = *s) && !IS_B85(c) ) ++s;
  return s;
}

/* Convert small integer, known to be in 0..84 inclusive, to base85 numeral.
 * Do not use the macro form with argument expression having a side-effect.*/
#if 0
static char base85Numeral( u8 b ){
  return (b < 4)? (char)(b + '#') : (char)(b - 4 + '*');
}
#else
# define base85Numeral( dn )\
  ((char)(((dn) < 4)? (char)((dn) + '#') : (char)((dn) - 4 + '*')))
#endif

static char *putcs(char *pc, char *s){
  char c;
  while( (c = *s++)!=0 ) *pc++ = c;
  return pc;
}

/* Encode a byte buffer into base85 text. If pSep!=0, it's a C string
** to be appended to encoded groups to limit their length to B85_DARK_MAX
** or to terminate the last group (to aid concatenation.)
*/
static char* toBase85( u8 *pIn, int nbIn, char *pOut, char *pSep ){
  int nCol = 0;
  while( nbIn >= 4 ){
    int nco = 5;
    unsigned long qbv = (((unsigned long)pIn[0])<<24) |
                        (pIn[1]<<16) | (pIn[2]<<8) | pIn[3];
    while( nco > 0 ){
      unsigned nqv = (unsigned)(qbv/85UL);
      unsigned char dv = qbv - 85UL*nqv;
      qbv = nqv;
      pOut[--nco] = base85Numeral(dv);
    }
    nbIn -= 4;
    pIn += 4;
    pOut += 5;
    if( pSep && (nCol += 5)>=B85_DARK_MAX ){
      pOut = putcs(pOut, pSep);
      nCol = 0;
    }
  }
  if( nbIn > 0 ){
    int nco = nbIn + 1;
    unsigned long qv = *pIn++;
    int nbe = 1;
    while( nbe++ < nbIn ){
      qv = (qv<<8) | *pIn++;
    }
    nCol += nco;
    while( nco > 0 ){
      u8 dv = (u8)(qv % 85);
      qv /= 85;
      pOut[--nco] = base85Numeral(dv);
    }
    pOut += (nbIn+1);
  }
  if( pSep && nCol>0 ) pOut = putcs(pOut, pSep);
  *pOut = 0;
  return pOut;
}

/* Decode base85 text into a byte buffer. */
static u8* fromBase85( char *pIn, int ncIn, u8 *pOut ){
  if( ncIn>0 && pIn[ncIn-1]=='\n' ) --ncIn;
  while( ncIn>0 ){
    static signed char nboi[] = { 0, 0, 1, 2, 3, 4 };
    char *pUse = skipNonB85(pIn, ncIn);
    unsigned long qv = 0L;
    int nti, nbo;
    ncIn -= (pUse - pIn);
    pIn = pUse;
    nti = (ncIn>5)? 5 : ncIn;
    nbo = nboi[nti];
    if( nbo==0 ) break;
    while( nti>0 ){
      char c = *pIn++;
      u8 cdo = B85_DNOS(c);
      --ncIn;
      if( cdo==0 ) break;
      qv = 85 * qv + (c - cdo);
      --nti;
    }
    nbo -= nti; /* Adjust for early (non-digit) end of group. */
    switch( nbo ){
    case 4:
      *pOut++ = (qv >> 24)&0xff;
      /* FALLTHRU */
    case 3:
      *pOut++ = (qv >> 16)&0xff;
      /* FALLTHRU */
    case 2:
      *pOut++ = (qv >> 8)&0xff;
      /* FALLTHRU */
    case 1:
      *pOut++ = qv&0xff;
      /* FALLTHRU */
    case 0:
      break;
    }
  }
  return pOut;
}

#ifndef OMIT_BASE85_CHECKER
/* Say whether input char sequence is all (base85 and/or whitespace).*/
static int allBase85( char *p, int len ){
  char c;
  while( len-- > 0 && (c = *p++) != 0 ){
    if( !IS_B85(c) && !isspace(c) ) return 0;
  }
  return 1;
}
#endif

#ifndef BASE85_STANDALONE

#ifndef OMIT_BASE85_CHECKER
/* This function does the work for the SQLite is_base85(t) UDF. */
static void is_base85(sqlite3_context *context, int na, sqlite3_value *av[]){
  assert(na==1);
  switch( sqlite3_value_type(av[0]) ){
  case SQLITE_TEXT:
    {
      int rv = allBase85( (char *)sqlite3_value_text(av[0]),
                          sqlite3_value_bytes(av[0]) );
      sqlite3_result_int(context, rv);
    }
    break;
  case SQLITE_NULL:
    sqlite3_result_null(context);
    break;
  default:
    sqlite3_result_error(context, "is_base85 accepts only text or NULL", -1);
    return;
  }
}
#endif

/* This function does the work for the SQLite base85(x) UDF. */
static void base85(sqlite3_context *context, int na, sqlite3_value *av[]){
  sqlite3_int64 nb, nc, nv = sqlite3_value_bytes(av[0]);
  int nvMax = sqlite3_limit(sqlite3_context_db_handle(context),
                            SQLITE_LIMIT_LENGTH, -1);
  char *cBuf;
  u8 *bBuf;
  assert(na==1);
  switch( sqlite3_value_type(av[0]) ){
  case SQLITE_BLOB:
    nb = nv;
    /*    ulongs    tail   newlines  tailenc+nul*/
    nc = 5*(nv/4) + nv%4 + nv/64+1 + 2;
    if( nvMax < nc ){
      sqlite3_result_error(context, "blob expanded to base85 too big", -1);
      return;
    }
    bBuf = (u8*)sqlite3_value_blob(av[0]);
    if( !bBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_text(context,"",-1,SQLITE_STATIC);
      break;
    }
    cBuf = sqlite3_malloc64(nc);
    if( !cBuf ) goto memFail;
    nc = (int)(toBase85(bBuf, nb, cBuf, "\n") - cBuf);
    sqlite3_result_text(context, cBuf, nc, sqlite3_free);
    break;
  case SQLITE_TEXT:
    nc = nv;
    nb = 4*(nv/5) + nv%5; /* may overestimate */
    if( nvMax < nb ){
      sqlite3_result_error(context, "blob from base85 may be too big", -1);
      return;
    }else if( nb<1 ){
      nb = 1;
    }
    cBuf = (char *)sqlite3_value_text(av[0]);
    if( !cBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_zeroblob(context, 0);
      break;
    }
    bBuf = sqlite3_malloc64(nb);
    if( !bBuf ) goto memFail;
    nb = (int)(fromBase85(cBuf, nc, bBuf) - bBuf);
    sqlite3_result_blob(context, bBuf, nb, sqlite3_free);
    break;
  default:
    sqlite3_result_error(context, "base85 accepts only blob or text.", -1);
    return;
  }
  return;
 memFail:
  sqlite3_result_error(context, "base85 OOM", -1);
}

/*
** Establish linkage to running SQLite library.
*/
#ifndef SQLITE_SHELL_EXTFUNCS
#ifdef _WIN32

#endif
int sqlite3_base85_init
#else
static int sqlite3_base85_init
#endif
(sqlite3 *db, char **pzErr, const sqlite3_api_routines *pApi){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErr;
#ifndef OMIT_BASE85_CHECKER
  {
    int rc = sqlite3_create_function
      (db, "is_base85", 1,
       SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS|SQLITE_UTF8,
       0, is_base85, 0, 0);
    if( rc!=SQLITE_OK ) return rc;
  }
#endif
  return sqlite3_create_function
    (db, "base85", 1,
     SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS|SQLITE_DIRECTONLY|SQLITE_UTF8,
     0, base85, 0, 0);
}

/*
** Define some macros to allow this extension to be built into the shell
** conveniently, in conjunction with use of SQLITE_SHELL_EXTFUNCS. This
** allows shell.c, as distributed, to have this extension built in.
*/
# define BASE85_INIT(db) sqlite3_base85_init(db, 0, 0)
# define BASE85_EXPOSE(db, pzErr) /* Not needed, ..._init() does this. */

#else /* standalone program */

int main(int na, char *av[]){
  int cin;
  int rc = 0;
  u8 bBuf[4*(B85_DARK_MAX/5)];
  char cBuf[5*(sizeof(bBuf)/4)+2];
  size_t nio;
# ifndef OMIT_BASE85_CHECKER
  int b85Clean = 1;
# endif
  char rw;
  FILE *fb = 0, *foc = 0;
  char fmode[3] = "xb";
  if( na < 3 || av[1][0]!='-' || (rw = av[1][1])==0 || (rw!='r' && rw!='w') ){
    sayHelp();
    return 0;
  }
  fmode[0] = rw;
  if( av[2][0]=='-' && av[2][1]==0 ){
    switch( rw ){
    case 'r':
      fb = stdin;
      setmode(fileno(stdin), O_BINARY);
      break;
    case 'w':
      fb = stdout;
      setmode(fileno(stdout), O_BINARY);
      break;
    }
  }else{
    fb = fopen(av[2], fmode);
    foc = fb;
  }
  if( !fb ){
    fprintf(stderr, "Cannot open %s for %c\n", av[2], rw);
    rc = 1;
  }else{
    switch( rw ){
    case 'r':
      while( (nio = fread( bBuf, 1, sizeof(bBuf), fb))>0 ){
        toBase85( bBuf, (int)nio, cBuf, 0 );
        fprintf(stdout, "%s\n", cBuf);
      }
      break;
    case 'w':
      while( 0 != fgets(cBuf, sizeof(cBuf), stdin) ){
        int nc = strlen(cBuf);
        size_t nbo = fromBase85( cBuf, nc, bBuf ) - bBuf;
        if( 1 != fwrite(bBuf, nbo, 1, fb) ) rc = 1;
#ifndef OMIT_BASE85_CHECKER
        b85Clean &= allBase85( cBuf, nc );
#endif
      }
      break;
    default:
      sayHelp();
      rc = 1;
    }
    if( foc ) fclose(foc);
  }
# ifndef OMIT_BASE85_CHECKER
  if( !b85Clean ){
    fprintf(stderr, "Base85 input had non-base85 dark or control content.\n");
  }
# endif
  return rc;
}

#endif

/************************* End ext/misc/base85.c ********************/
/************************* Begin ext/misc/ieee754.c ******************/
/*
** 2013-04-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions for the exact display
** and input of IEEE754 Binary64 floating-point numbers.
**
**   ieee754(X)
**   ieee754(Y,Z)
**
** In the first form, the value X should be a floating-point number.
** The function will return a string of the form 'ieee754(Y,Z)' where
** Y and Z are integers such that X==Y*pow(2,Z).
**
** In the second form, Y and Z are integers which are the mantissa and
** base-2 exponent of a new floating point number.  The function returns
** a floating-point value equal to Y*pow(2,Z).
**
** Examples:
**
**     ieee754(2.0)             ->     'ieee754(2,0)'
**     ieee754(45.25)           ->     'ieee754(181,-2)'
**     ieee754(2, 0)            ->     2.0
**     ieee754(181, -2)         ->     45.25
**
** Two additional functions break apart the one-argument ieee754()
** result into separate integer values:
**
**     ieee754_mantissa(45.25)  ->     181
**     ieee754_exponent(45.25)  ->     -2
**
** These functions convert binary64 numbers into blobs and back again.
**
**     ieee754_from_blob(x'3ff0000000000000')  ->  1.0
**     ieee754_to_blob(1.0)                    ->  x'3ff0000000000000'
**
** In all single-argument functions, if the argument is an 8-byte blob
** then that blob is interpreted as a big-endian binary64 value.
**
**
** EXACT DECIMAL REPRESENTATION OF BINARY64 VALUES
** -----------------------------------------------
**
** This extension in combination with the separate 'decimal' extension
** can be used to compute the exact decimal representation of binary64
** values.  To begin, first compute a table of exponent values:
**
**    CREATE TABLE pow2(x INTEGER PRIMARY KEY, v TEXT);
**    WITH RECURSIVE c(x,v) AS (
**      VALUES(0,'1')
**      UNION ALL
**      SELECT x+1, decimal_mul(v,'2') FROM c WHERE x+1<=971
**    ) INSERT INTO pow2(x,v) SELECT x, v FROM c;
**    WITH RECURSIVE c(x,v) AS (
**      VALUES(-1,'0.5')
**      UNION ALL
**      SELECT x-1, decimal_mul(v,'0.5') FROM c WHERE x-1>=-1075
**    ) INSERT INTO pow2(x,v) SELECT x, v FROM c;
**
** Then, to compute the exact decimal representation of a floating
** point value (the value 47.49 is used in the example) do:
**
**    WITH c(n) AS (VALUES(47.49))
**          ---------------^^^^^---- Replace with whatever you want
**    SELECT decimal_mul(ieee754_mantissa(c.n),pow2.v)
**      FROM pow2, c WHERE pow2.x=ieee754_exponent(c.n);
**
** Here is a query to show various boundry values for the binary64
** number format:
**
**    WITH c(name,bin) AS (VALUES
**       ('minimum positive value',        x'0000000000000001'),
**       ('maximum subnormal value',       x'000fffffffffffff'),
**       ('minimum positive normal value', x'0010000000000000'),
**       ('maximum value',                 x'7fefffffffffffff'))
**    SELECT c.name, decimal_mul(ieee754_mantissa(c.bin),pow2.v)
**      FROM pow2, c WHERE pow2.x=ieee754_exponent(c.bin);
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

/* Mark a function parameter as unused, to suppress nuisance compiler
** warnings. */
#ifndef UNUSED_PARAMETER
# define UNUSED_PARAMETER(X)  (void)(X)
#endif

/*
** Implementation of the ieee754() function
*/
static void ieee754func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  if( argc==1 ){
    sqlite3_int64 m, a;
    double r;
    int e;
    int isNeg;
    char zResult[100];
    assert( sizeof(m)==sizeof(r) );
    if( sqlite3_value_type(argv[0])==SQLITE_BLOB
     && sqlite3_value_bytes(argv[0])==sizeof(r)
    ){
      const unsigned char *x = sqlite3_value_blob(argv[0]);
      unsigned int i;
      sqlite3_uint64 v = 0;
      for(i=0; i<sizeof(r); i++){
        v = (v<<8) | x[i];
      }
      memcpy(&r, &v, sizeof(r));
    }else{
      r = sqlite3_value_double(argv[0]);
    }
    if( r<0.0 ){
      isNeg = 1;
      r = -r;
    }else{
      isNeg = 0;
    }
    memcpy(&a,&r,sizeof(a));
    if( a==0 ){
      e = 0;
      m = 0;
    }else if( a==(sqlite3_int64)0x8000000000000000LL ){
      e = -1996;
      m = -1;
    }else{
      e = a>>52;
      m = a & ((((sqlite3_int64)1)<<52)-1);
      if( e==0 ){
        m <<= 1;
      }else{
        m |= ((sqlite3_int64)1)<<52;
      }
      while( e<1075 && m>0 && (m&1)==0 ){
        m >>= 1;
        e++;
      }
      if( isNeg ) m = -m;
    }
    switch( *(int*)sqlite3_user_data(context) ){
      case 0:
        sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
                         m, e-1075);
        sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
        break;
      case 1:
        sqlite3_result_int64(context, m);
        break;
      case 2:
        sqlite3_result_int(context, e-1075);
        break;
    }
  }else{
    sqlite3_int64 m, e, a;
    double r;
    int isNeg = 0;
    m = sqlite3_value_int64(argv[0]);
    e = sqlite3_value_int64(argv[1]);

    /* Limit the range of e.  Ticket 22dea1cfdb9151e4 2021-03-02 */
    if( e>10000 ){
      e = 10000;
    }else if( e<-10000 ){
      e = -10000;
    }

    if( m<0 ){
      if( m<(-9223372036854775807LL) ) return;
      isNeg = 1;
      m = -m;
    }else if( m==0 && e>-1000 && e<1000 ){
      sqlite3_result_double(context, 0.0);
      return;
    }
    while( (m>>32)&0xffe00000 ){
      m >>= 1;
      e++;
    }
    while( m!=0 && ((m>>32)&0xfff00000)==0 ){
      m <<= 1;
      e--;
    }
    e += 1075;
    if( e<=0 ){
      /* Subnormal */
      if( 1-e >= 64 ){
        m = 0;
      }else{
        m >>= 1-e;
      }
      e = 0;
    }else if( e>0x7ff ){
      e = 0x7ff;
    }
    a = m & ((((sqlite3_int64)1)<<52)-1);
    a |= e<<52;
    if( isNeg ) a |= ((sqlite3_uint64)1)<<63;
    memcpy(&r, &a, sizeof(r));
    sqlite3_result_double(context, r);
  }
}

/*
** Functions to convert between blobs and floats.
*/
static void ieee754func_from_blob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
   && sqlite3_value_bytes(argv[0])==sizeof(double)
  ){
    double r;
    const unsigned char *x = sqlite3_value_blob(argv[0]);
    unsigned int i;
    sqlite3_uint64 v = 0;
    for(i=0; i<sizeof(r); i++){
      v = (v<<8) | x[i];
    }
    memcpy(&r, &v, sizeof(r));
    sqlite3_result_double(context, r);
  }
}
static void ieee754func_to_blob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_FLOAT
   || sqlite3_value_type(argv[0])==SQLITE_INTEGER
  ){
    double r = sqlite3_value_double(argv[0]);
    sqlite3_uint64 v;
    unsigned char a[sizeof(r)];
    unsigned int i;
    memcpy(&v, &r, sizeof(r));
    for(i=1; i<=sizeof(r); i++){
      a[sizeof(r)-i] = v&0xff;
      v >>= 8;
    }
    sqlite3_result_blob(context, a, sizeof(r), SQLITE_TRANSIENT);
  }
}

/*
** Functions to convert between 64-bit integers and floats.
**
** The bit patterns are copied.  The numeric values are different.
*/
static void ieee754func_from_int(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_INTEGER ){
    double r;
    sqlite3_int64 v = sqlite3_value_int64(argv[0]);
    memcpy(&r, &v, sizeof(r));
    sqlite3_result_double(context, r);
  }
}
static void ieee754func_to_int(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_FLOAT ){
    double r = sqlite3_value_double(argv[0]);
    sqlite3_uint64 v;
    memcpy(&v, &r, sizeof(v));
    sqlite3_result_int64(context, v);
  }
}

/*
** SQL Function:   ieee754_inc(r,N)
**
** Move the floating point value r by N quantums and return the new
** values.
**
** Behind the scenes: this routine merely casts r into a 64-bit unsigned
** integer, adds N, then casts the value back into float.
**
** Example:  To find the smallest positive number:
**
**     SELECT ieee754_inc(0.0,+1);
*/
static void ieee754inc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  double r;
  sqlite3_int64 N;
  sqlite3_uint64 m1, m2;
  double r2;
  UNUSED_PARAMETER(argc);
  r = sqlite3_value_double(argv[0]);
  N = sqlite3_value_int64(argv[1]);
  memcpy(&m1, &r, 8);
  m2 = m1 + N;
  memcpy(&r2, &m2, 8);
  sqlite3_result_double(context, r2);
}


#ifdef _WIN32

#endif
int sqlite3_ieee_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  static const struct {
    char *zFName;
    int nArg;
    int iAux;
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {
    { "ieee754",           1,   0, ieee754func },
    { "ieee754",           2,   0, ieee754func },
    { "ieee754_mantissa",  1,   1, ieee754func },
    { "ieee754_exponent",  1,   2, ieee754func },
    { "ieee754_to_blob",   1,   0, ieee754func_to_blob },
    { "ieee754_from_blob", 1,   0, ieee754func_from_blob },
    { "ieee754_to_int",    1,   0, ieee754func_to_int },
    { "ieee754_from_int",  1,   0, ieee754func_from_int },
    { "ieee754_inc",       2,   0, ieee754inc  },
  };
  unsigned int i;
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zFName, aFunc[i].nArg,
                               SQLITE_UTF8|SQLITE_INNOCUOUS,
                               (void*)&aFunc[i].iAux,
                               aFunc[i].xFunc, 0, 0);
  }
  return rc;
}
#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db, 
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "ieee754", 1, SQLITE_UTF8, 0,
                               ieee754func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "ieee754", 2, SQLITE_UTF8, 0,
                                 ieee754func, 0, 0);
  }
  return rc;
}
#endif

/************************* End ext/misc/ieee754.c ********************/
/************************* Begin ext/misc/series.c ******************/
/*
** 2015-08-18, 2023-04-28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file demonstrates how to create a table-valued-function using
** a virtual table.  This demo implements the generate_series() function
** which gives the same results as the eponymous function in PostgreSQL,
** within the limitation that its arguments are signed 64-bit integers.
**
** Considering its equivalents to generate_series(start,stop,step): A
** value V[n] sequence is produced for integer n ascending from 0 where
**  ( V[n] == start + n * step  &&  sgn(V[n] - stop) * sgn(step) >= 0 )
** for each produced value (independent of production time ordering.)
**
** All parameters must be either integer or convertable to integer.
** The start parameter is required.
** The stop parameter defaults to (1<<32)-1 (aka 4294967295 or 0xffffffff)
** The step parameter defaults to 1 and 0 is treated as 1.
**
** Examples:
**
**      SELECT * FROM generate_series(0,100,5);
**
** The query above returns integers from 0 through 100 counting by steps
** of 5.  In other words, 0, 5, 10, 15, ..., 90, 95, 100.  There are a total
** of 21 rows.
**
**      SELECT * FROM generate_series(0,100);
**
** Integers from 0 through 100 with a step size of 1.  101 rows.
**
**      SELECT * FROM generate_series(20) LIMIT 10;
**
** Integers 20 through 29.  10 rows.
**
**      SELECT * FROM generate_series(0,-100,-5);
**
** Integers 0 -5 -10 ... -100.  21 rows.
**
**      SELECT * FROM generate_series(0,-1);
**
** Empty sequence.
**
** HOW IT WORKS
**
** The generate_series "function" is really a virtual table with the
** following schema:
**
**     CREATE TABLE generate_series(
**       value,
**       start HIDDEN,
**       stop HIDDEN,
**       step HIDDEN
**     );
**
** The virtual table also has a rowid which is an alias for the value.
**
** Function arguments in queries against this virtual table are translated
** into equality constraints against successive hidden columns.  In other
** words, the following pairs of queries are equivalent to each other:
**
**    SELECT * FROM generate_series(0,100,5);
**    SELECT * FROM generate_series WHERE start=0 AND stop=100 AND step=5;
**
**    SELECT * FROM generate_series(0,100);
**    SELECT * FROM generate_series WHERE start=0 AND stop=100;
**
**    SELECT * FROM generate_series(20) LIMIT 10;
**    SELECT * FROM generate_series WHERE start=20 LIMIT 10;
**
** The generate_series virtual table implementation leaves the xCreate method
** set to NULL.  This means that it is not possible to do a CREATE VIRTUAL
** TABLE command with "generate_series" as the USING argument.  Instead, there
** is a single generate_series virtual table that is always available without
** having to be created first.
**
** The xBestIndex method looks for equality constraints against the hidden
** start, stop, and step columns, and if present, it uses those constraints
** to bound the sequence of generated values.  If the equality constraints
** are missing, it uses 0 for start, 4294967295 for stop, and 1 for step.
** xBestIndex returns a small cost when both start and stop are available,
** and a very large cost if either start or stop are unavailable.  This
** encourages the query planner to order joins such that the bounds of the
** series are well-defined.
**
** Update on 2024-08-22:
** xBestIndex now also looks for equality and inequality constraints against
** the value column and uses those constraints as additional bounds against
** the sequence range.  Thus, a query like this:
**
**     SELECT value FROM generate_series($SA,$EA)
**      WHERE value BETWEEN $SB AND $EB;
**
** Is logically the same as:
**
**     SELECT value FROM generate_series(max($SA,$SB),min($EA,$EB));
**
** Constraints on the value column can server as substitutes for constraints
** on the hidden start and stop columns.  So, the following two queries
** are equivalent:
**
**     SELECT value FROM generate_series($S,$E);
**     SELECT value FROM generate_series WHERE value BETWEEN $S and $E;
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <limits.h>
#include <math.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/* series_cursor is a subclass of sqlite3_vtab_cursor which will
** serve as the underlying representation of a cursor that scans
** over rows of the result.
**
** iOBase, iOTerm, and iOStep are the original values of the
** start=, stop=, and step= constraints on the query.  These are
** the values reported by the start, stop, and step columns of the
** virtual table.
**
** iBase, iTerm, iStep, and bDescp are the actual values used to generate
** the sequence.  These might be different from the iOxxxx values.
** For example in
**
**   SELECT value FROM generate_series(1,11,2)
**    WHERE value BETWEEN 4 AND 8;
**
** The iOBase is 1, but the iBase is 5.  iOTerm is 11 but iTerm is 7.
** Another example:
**
**   SELECT value FROM generate_series(1,15,3) ORDER BY value DESC;
**
** The cursor initialization for the above query is:
**
**   iOBase = 1        iBase = 13
**   iOTerm = 15       iTerm = 1
**   iOStep = 3        iStep = 3      bDesc = 1
**
** The actual step size is unsigned so that can have a value of
** +9223372036854775808 which is needed for querys like this:
**
**   SELECT value
**     FROM generate_series(9223372036854775807,
**                          -9223372036854775808,
**                          -9223372036854775808)
**    ORDER BY value ASC;
**
** The setup for the previous query will be:
**
**   iOBase = 9223372036854775807    iBase = -1
**   iOTerm = -9223372036854775808   iTerm = 9223372036854775807
**   iOStep = -9223372036854775808   iStep = 9223372036854775808  bDesc = 0
*/
/* typedef unsigned char u8; */
typedef struct series_cursor series_cursor;
struct series_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  sqlite3_int64 iOBase;      /* Original starting value ("start") */
  sqlite3_int64 iOTerm;      /* Original terminal value ("stop") */
  sqlite3_int64 iOStep;      /* Original step value */
  sqlite3_int64 iBase;       /* Starting value to actually use */
  sqlite3_int64 iTerm;       /* Terminal value to actually use */
  sqlite3_uint64 iStep;      /* The step size */
  sqlite3_int64 iValue;      /* Current value */
  u8 bDesc;                  /* iStep is really negative */
  u8 bDone;                  /* True if stepped past last element */
};

/*
** Computed the difference between two 64-bit signed integers using a
** convoluted computation designed to work around the silly restriction
** against signed integer overflow in C.
*/
static sqlite3_uint64 span64(sqlite3_int64 a, sqlite3_int64 b){
  assert( a>=b );
  return (*(sqlite3_uint64*)&a) - (*(sqlite3_uint64*)&b);
}  

/*
** Add or substract an unsigned 64-bit integer from a signed 64-bit integer
** and return the new signed 64-bit integer.
*/
static sqlite3_int64 add64(sqlite3_int64 a, sqlite3_uint64 b){
  sqlite3_uint64 x = *(sqlite3_uint64*)&a;
  x += b;
  return *(sqlite3_int64*)&x;
}
static sqlite3_int64 sub64(sqlite3_int64 a, sqlite3_uint64 b){
  sqlite3_uint64 x = *(sqlite3_uint64*)&a;
  x -= b;
  return *(sqlite3_int64*)&x;
}

/*
** The seriesConnect() method is invoked to create a new
** series_vtab that describes the generate_series virtual table.
**
** Think of this routine as the constructor for series_vtab objects.
**
** All this routine needs to do is:
**
**    (1) Allocate the series_vtab object and initialize all fields.
**
**    (2) Tell SQLite (via the sqlite3_declare_vtab() interface) what the
**        result set of queries against generate_series will look like.
*/
static int seriesConnect(
  sqlite3 *db,
  void *pUnused,
  int argcUnused, const char *const*argvUnused,
  sqlite3_vtab **ppVtab,
  char **pzErrUnused
){
  sqlite3_vtab *pNew;
  int rc;

/* Column numbers */
#define SERIES_COLUMN_ROWID (-1)
#define SERIES_COLUMN_VALUE 0
#define SERIES_COLUMN_START 1
#define SERIES_COLUMN_STOP  2
#define SERIES_COLUMN_STEP  3

  (void)pUnused;
  (void)argcUnused;
  (void)argvUnused;
  (void)pzErrUnused;
  rc = sqlite3_declare_vtab(db,
     "CREATE TABLE x(value,start hidden,stop hidden,step hidden)");
  if( rc==SQLITE_OK ){
    pNew = *ppVtab = sqlite3_malloc64( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    sqlite3_vtab_config(db, SQLITE_VTAB_INNOCUOUS);
  }
  return rc;
}

/*
** This method is the destructor for series_cursor objects.
*/
static int seriesDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new series_cursor object.
*/
static int seriesOpen(sqlite3_vtab *pUnused, sqlite3_vtab_cursor **ppCursor){
  series_cursor *pCur;
  (void)pUnused;
  pCur = sqlite3_malloc64( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Destructor for a series_cursor.
*/
static int seriesClose(sqlite3_vtab_cursor *cur){
  sqlite3_free(cur);
  return SQLITE_OK;
}


/*
** Advance a series_cursor to its next row of output.
*/
static int seriesNext(sqlite3_vtab_cursor *cur){
  series_cursor *pCur = (series_cursor*)cur;
  if( pCur->iValue==pCur->iTerm ){
    pCur->bDone = 1;
  }else if( pCur->bDesc ){
    pCur->iValue = sub64(pCur->iValue, pCur->iStep);
    assert( pCur->iValue>=pCur->iTerm );
  }else{
    pCur->iValue = add64(pCur->iValue, pCur->iStep);
    assert( pCur->iValue<=pCur->iTerm );
  }
  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the series_cursor
** is currently pointing.
*/
static int seriesColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  series_cursor *pCur = (series_cursor*)cur;
  sqlite3_int64 x = 0;
  switch( i ){
    case SERIES_COLUMN_START:  x = pCur->iOBase;     break;
    case SERIES_COLUMN_STOP:   x = pCur->iOTerm;     break;
    case SERIES_COLUMN_STEP:   x = pCur->iOStep;     break;
    default:                   x = pCur->iValue;     break;
  }
  sqlite3_result_int64(ctx, x);
  return SQLITE_OK;
}

#ifndef LARGEST_UINT64
#define LARGEST_INT64  ((sqlite3_int64)0x7fffffffffffffffLL)
#define LARGEST_UINT64 ((sqlite3_uint64)0xffffffffffffffffULL)
#define SMALLEST_INT64 ((sqlite3_int64)0x8000000000000000LL)
#endif

/*
** The rowid is the same as the value.
*/
static int seriesRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  series_cursor *pCur = (series_cursor*)cur;
  *pRowid = pCur->iValue;
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int seriesEof(sqlite3_vtab_cursor *cur){
  series_cursor *pCur = (series_cursor*)cur;
  return pCur->bDone;
}

/* True to cause run-time checking of the start=, stop=, and/or step=
** parameters.  The only reason to do this is for testing the
** constraint checking logic for virtual tables in the SQLite core.
*/
#ifndef SQLITE_SERIES_CONSTRAINT_VERIFY
# define SQLITE_SERIES_CONSTRAINT_VERIFY 0
#endif

/*
** Return the number of steps between pCur->iBase and pCur->iTerm if
** the step width is pCur->iStep.
*/
static sqlite3_uint64 seriesSteps(series_cursor *pCur){
  if( pCur->bDesc ){
    assert( pCur->iBase >= pCur->iTerm );
    return span64(pCur->iBase, pCur->iTerm)/pCur->iStep;
  }else{
    assert( pCur->iBase <= pCur->iTerm );
    return span64(pCur->iTerm, pCur->iBase)/pCur->iStep;
  }
}

#if defined(SQLITE_ENABLE_MATH_FUNCTIONS) || defined(_WIN32)
/*
** Case 1 (the most common case):
** The standard math library is available so use ceil() and floor() from there.
*/
static double seriesCeil(double r){ return ceil(r); }
static double seriesFloor(double r){ return floor(r); }
#elif defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)
/*
** Case 2 (2nd most common): Use GCC/Clang builtins
*/
static double seriesCeil(double r){ return __builtin_ceil(r); }
static double seriesFloor(double r){ return __builtin_floor(r); }
#else
/*
** Case 3 (rarely happens): Use home-grown ceil() and floor() routines.
*/
static double seriesCeil(double r){
  sqlite3_int64 x;
  if( r!=r ) return r;
  if( r<=(-4503599627370496.0) ) return r;
  if( r>=(+4503599627370496.0) ) return r;
  x = (sqlite3_int64)r;
  if( r==(double)x ) return r;
  if( r>(double)x ) x++;
  return (double)x;
}
static double seriesFloor(double r){
  sqlite3_int64 x;
  if( r!=r ) return r;
  if( r<=(-4503599627370496.0) ) return r;
  if( r>=(+4503599627370496.0) ) return r;
  x = (sqlite3_int64)r;
  if( r==(double)x ) return r;
  if( r<(double)x ) x--;
  return (double)x;
}
#endif

/*
** This method is called to "rewind" the series_cursor object back
** to the first row of output.  This method is always called at least
** once prior to any call to seriesColumn() or seriesRowid() or
** seriesEof().
**
** The query plan selected by seriesBestIndex is passed in the idxNum
** parameter.  (idxStr is not used in this implementation.)  idxNum
** is a bitmask showing which constraints are available:
**
**   0x0001:    start=VALUE
**   0x0002:    stop=VALUE
**   0x0004:    step=VALUE
**   0x0008:    descending order
**   0x0010:    ascending order
**   0x0020:    LIMIT  VALUE
**   0x0040:    OFFSET  VALUE
**   0x0080:    value=VALUE
**   0x0100:    value>=VALUE
**   0x0200:    value>VALUE
**   0x1000:    value<=VALUE
**   0x2000:    value<VALUE
**
** This routine should initialize the cursor and position it so that it
** is pointing at the first row, or pointing off the end of the table
** (so that seriesEof() will return true) if the table is empty.
*/
static int seriesFilter(
  sqlite3_vtab_cursor *pVtabCursor,
  int idxNum, const char *idxStrUnused,
  int argc, sqlite3_value **argv
){
  series_cursor *pCur = (series_cursor *)pVtabCursor;
  int iArg = 0;                         /* Arguments used so far */
  int i;                                /* Loop counter */
  sqlite3_int64 iMin = SMALLEST_INT64;  /* Smallest allowed output value */
  sqlite3_int64 iMax = LARGEST_INT64;   /* Largest allowed output value */
  sqlite3_int64 iLimit = 0;             /* if >0, the value of the LIMIT */
  sqlite3_int64 iOffset = 0;            /* if >0, the value of the OFFSET */

  (void)idxStrUnused;

  /* If any constraints have a NULL value, then return no rows.
  ** See ticket https://sqlite.org/src/info/fac496b61722daf2
  */
  for(i=0; i<argc; i++){
    if( sqlite3_value_type(argv[i])==SQLITE_NULL ){
      goto series_no_rows;
    }
  }

  /* Capture the three HIDDEN parameters to the virtual table and insert
  ** default values for any parameters that are omitted.
  */
  if( idxNum & 0x01 ){
    pCur->iOBase = sqlite3_value_int64(argv[iArg++]);
  }else{
    pCur->iOBase = 0;
  }
  if( idxNum & 0x02 ){
    pCur->iOTerm = sqlite3_value_int64(argv[iArg++]);
  }else{
    pCur->iOTerm = 0xffffffff;
  }
  if( idxNum & 0x04 ){
    pCur->iOStep = sqlite3_value_int64(argv[iArg++]);
    if( pCur->iOStep==0 ) pCur->iOStep = 1;
  }else{
    pCur->iOStep = 1;
  }

  /* If there are constraints on the value column but there are
  ** no constraints on  the start, stop, and step columns, then
  ** initialize the default range to be the entire range of 64-bit signed
  ** integers.  This range will contracted by the value column constraints
  ** further below.
  */
  if( (idxNum & 0x05)==0 && (idxNum & 0x0380)!=0 ){
    pCur->iOBase = SMALLEST_INT64;
  }
  if( (idxNum & 0x06)==0 && (idxNum & 0x3080)!=0 ){
    pCur->iOTerm = LARGEST_INT64;
  }
  pCur->iBase = pCur->iOBase;
  pCur->iTerm = pCur->iOTerm;
  if( pCur->iOStep>0 ){  
    pCur->iStep = pCur->iOStep;
  }else if( pCur->iOStep>SMALLEST_INT64 ){
    pCur->iStep = -pCur->iOStep;
  }else{
    pCur->iStep = LARGEST_INT64;
    pCur->iStep++;
  }
  pCur->bDesc = pCur->iOStep<0;
  if( pCur->bDesc==0 && pCur->iBase>pCur->iTerm ){
    goto series_no_rows;
  }
  if( pCur->bDesc!=0 && pCur->iBase<pCur->iTerm ){
    goto series_no_rows;
  }

  /* Extract the LIMIT and OFFSET values, but do not apply them yet.
  ** The range must first be constrained by the limits on value.
  */
  if( idxNum & 0x20 ){
    iLimit = sqlite3_value_int64(argv[iArg++]);
    if( idxNum & 0x40 ){
      iOffset = sqlite3_value_int64(argv[iArg++]);
    }
  }

  /* Narrow the range of iMin and iMax (the minimum and maximum outputs)
  ** based on equality and inequality constraints on the "value" column.
  */
  if( idxNum & 0x3380 ){
    if( idxNum & 0x0080 ){    /* value=X */
      if( sqlite3_value_numeric_type(argv[iArg])==SQLITE_FLOAT ){
        double r = sqlite3_value_double(argv[iArg++]);
        if( r==seriesCeil(r)
         && r>=(double)SMALLEST_INT64
         && r<=(double)LARGEST_INT64
        ){
          iMin = iMax = (sqlite3_int64)r;
        }else{
          goto series_no_rows;
        }
      }else{
        iMin = iMax = sqlite3_value_int64(argv[iArg++]);
      }
    }else{
      if( idxNum & 0x0300 ){  /* value>X or value>=X */
        if( sqlite3_value_numeric_type(argv[iArg])==SQLITE_FLOAT ){
          double r = sqlite3_value_double(argv[iArg++]);
          if( r<(double)SMALLEST_INT64 ){
            iMin = SMALLEST_INT64;
          }else if( (idxNum & 0x0200)!=0 && r==seriesCeil(r) ){
            iMin = (sqlite3_int64)seriesCeil(r+1.0);
          }else{
            iMin = (sqlite3_int64)seriesCeil(r);
          }
        }else{
          iMin = sqlite3_value_int64(argv[iArg++]);
          if( (idxNum & 0x0200)!=0 ){
            if( iMin==LARGEST_INT64 ){
              goto series_no_rows;
            }else{
              iMin++;
            }
          }
        }
      }
      if( idxNum & 0x3000 ){   /* value<X or value<=X */
        if( sqlite3_value_numeric_type(argv[iArg])==SQLITE_FLOAT ){
          double r = sqlite3_value_double(argv[iArg++]);
          if( r>(double)LARGEST_INT64 ){
            iMax = LARGEST_INT64;
          }else if( (idxNum & 0x2000)!=0 && r==seriesFloor(r) ){
            iMax = (sqlite3_int64)(r-1.0);
          }else{
            iMax = (sqlite3_int64)seriesFloor(r);
          }
        }else{
          iMax = sqlite3_value_int64(argv[iArg++]);
          if( idxNum & 0x2000 ){
            if( iMax==SMALLEST_INT64 ){
              goto series_no_rows;
            }else{
              iMax--;
            }
          }
        }
      }
      if( iMin>iMax ){
        goto series_no_rows;
      }
    }

    /* Try to reduce the range of values to be generated based on
    ** constraints on the "value" column.
    */
    if( pCur->bDesc==0 ){
      if( pCur->iBase<iMin ){
        sqlite3_uint64 span = span64(iMin,pCur->iBase);
        pCur->iBase = add64(pCur->iBase, (span/pCur->iStep)*pCur->iStep);
        if( pCur->iBase<iMin ){
          if( pCur->iBase > sub64(LARGEST_INT64, pCur->iStep) ){
            goto series_no_rows;
          }
          pCur->iBase = add64(pCur->iBase, pCur->iStep);
        }
      }
      if( pCur->iTerm>iMax ){
        pCur->iTerm = iMax;
      }
    }else{
      if( pCur->iBase>iMax ){
        sqlite3_uint64 span = span64(pCur->iBase,iMax);
        pCur->iBase = sub64(pCur->iBase, (span/pCur->iStep)*pCur->iStep);
        if( pCur->iBase>iMax ){
          if( pCur->iBase < add64(SMALLEST_INT64, pCur->iStep) ){
            goto series_no_rows;
          }
          pCur->iBase = sub64(pCur->iBase, pCur->iStep);
        }
      }
      if( pCur->iTerm<iMin ){
        pCur->iTerm = iMin;
      }
    }
  }

  /* Adjust iTerm so that it is exactly the last value of the series.
  */
  if( pCur->bDesc==0 ){
    if( pCur->iBase>pCur->iTerm ){
      goto series_no_rows;
    }
    pCur->iTerm = sub64(pCur->iTerm,
                        span64(pCur->iTerm,pCur->iBase) % pCur->iStep);
  }else{
    if( pCur->iBase<pCur->iTerm ){
      goto series_no_rows;
    }
    pCur->iTerm = add64(pCur->iTerm,
                        span64(pCur->iBase,pCur->iTerm) % pCur->iStep);
  }

  /* Transform the series generator to output values in the requested
  ** order.
  */
  if( ((idxNum & 0x0008)!=0 && pCur->bDesc==0)
   || ((idxNum & 0x0010)!=0 && pCur->bDesc!=0)
  ){
    sqlite3_int64 tmp = pCur->iBase;
    pCur->iBase = pCur->iTerm;
    pCur->iTerm = tmp;
    pCur->bDesc = !pCur->bDesc;
  }

  /* Apply LIMIT and OFFSET constraints, if any */
  assert( pCur->iStep!=0 );
  if( idxNum & 0x20 ){
    if( iOffset>0 ){
      if( seriesSteps(pCur) < (sqlite3_uint64)iOffset ){
        goto series_no_rows;
      }else if( pCur->bDesc ){
        pCur->iBase = sub64(pCur->iBase, pCur->iStep*iOffset);
      }else{
        pCur->iBase = add64(pCur->iBase, pCur->iStep*iOffset);
      }
    }
    if( iLimit>=0 && seriesSteps(pCur) > (sqlite3_uint64)iLimit ){
      pCur->iTerm = add64(pCur->iBase, (iLimit - 1)*pCur->iStep);
    }
  }
  pCur->iValue = pCur->iBase;
  pCur->bDone = 0;
  return SQLITE_OK;

series_no_rows:
  pCur->iBase = 0;
  pCur->iTerm = 0;
  pCur->iStep = 1;
  pCur->bDesc = 0;
  pCur->bDone = 1;
  return SQLITE_OK;  
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the generate_series virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** In this implementation idxNum is used to represent the
** query plan.  idxStr is unused.
**
** The query plan is represented by bits in idxNum:
**
**   0x0001  start = $num
**   0x0002  stop = $num
**   0x0004  step = $num
**   0x0008  output is in descending order
**   0x0010  output is in ascending order
**   0x0020  LIMIT $num
**   0x0040  OFFSET $num
**   0x0080  value = $num
**   0x0100  value >= $num
**   0x0200  value > $num
**   0x1000  value <= $num
**   0x2000  value < $num
**
** Only one of 0x0100 or 0x0200 will be returned.  Similarly, only
** one of 0x1000 or 0x2000 will be returned.  If the 0x0080 is set, then
** none of the 0xff00 bits will be set.
**
** The order of parameters passed to xFilter is as follows:
**
**    * The argument to start= if bit 0x0001 is in the idxNum mask
**    * The argument to stop= if bit 0x0002 is in the idxNum mask
**    * The argument to step= if bit 0x0004 is in the idxNum mask
**    * The argument to LIMIT if bit 0x0020 is in the idxNum mask
**    * The argument to OFFSET if bit 0x0040 is in the idxNum mask
**    * The argument to value=, or value>= or value> if any of
**      bits 0x0380 are in the idxNum mask
**    * The argument to value<= or value< if either of bits 0x3000
**      are in the mask
**
*/
static int seriesBestIndex(
  sqlite3_vtab *pVTab,
  sqlite3_index_info *pIdxInfo
){
  int i, j;              /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
  int bStartSeen = 0;    /* EQ constraint seen on the START column */
#endif
  int unusableMask = 0;  /* Mask of unusable constraints */
  int nArg = 0;          /* Number of arguments that seriesFilter() expects */
  int aIdx[7];           /* Constraints on start, stop, step, LIMIT, OFFSET,
                         ** and value.  aIdx[5] covers value=, value>=, and
                         ** value>,  aIdx[6] covers value<= and value< */
  const struct sqlite3_index_constraint *pConstraint;

  /* This implementation assumes that the start, stop, and step columns
  ** are the last three columns in the virtual table. */
  assert( SERIES_COLUMN_STOP == SERIES_COLUMN_START+1 );
  assert( SERIES_COLUMN_STEP == SERIES_COLUMN_START+2 );

  aIdx[0] = aIdx[1] = aIdx[2] = aIdx[3] = aIdx[4] = aIdx[5] = aIdx[6] = -1;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    int iCol;    /* 0 for start, 1 for stop, 2 for step */
    int iMask;   /* bitmask for those column */
    int op = pConstraint->op;
    if( op>=SQLITE_INDEX_CONSTRAINT_LIMIT
     && op<=SQLITE_INDEX_CONSTRAINT_OFFSET
    ){
      if( pConstraint->usable==0 ){
        /* do nothing */
      }else if( op==SQLITE_INDEX_CONSTRAINT_LIMIT ){
        aIdx[3] = i;
        idxNum |= 0x20;
      }else{
        assert( op==SQLITE_INDEX_CONSTRAINT_OFFSET );
        aIdx[4] = i;
        idxNum |= 0x40;
      }
      continue;
    }
    if( pConstraint->iColumn<SERIES_COLUMN_START ){
      if( (pConstraint->iColumn==SERIES_COLUMN_VALUE ||
           pConstraint->iColumn==SERIES_COLUMN_ROWID)
       && pConstraint->usable
      ){
        switch( op ){
          case SQLITE_INDEX_CONSTRAINT_EQ:
          case SQLITE_INDEX_CONSTRAINT_IS: {
            idxNum |=  0x0080;
            idxNum &= ~0x3300;
            aIdx[5] = i;
            aIdx[6] = -1;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
            bStartSeen = 1;
#endif
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_GE: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x0100;
            idxNum &= ~0x0200;
            aIdx[5] = i;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
            bStartSeen = 1;
#endif
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_GT: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x0200;
            idxNum &= ~0x0100;
            aIdx[5] = i;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
            bStartSeen = 1;
#endif
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_LE: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x1000;
            idxNum &= ~0x2000;
            aIdx[6] = i;
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_LT: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x2000;
            idxNum &= ~0x1000;
            aIdx[6] = i;
            break;
          }
        }
      }
      continue;
    }
    iCol = pConstraint->iColumn - SERIES_COLUMN_START;
    assert( iCol>=0 && iCol<=2 );
    iMask = 1 << iCol;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
    if( iCol==0 && op==SQLITE_INDEX_CONSTRAINT_EQ ){
      bStartSeen = 1;
    }
#endif
    if( pConstraint->usable==0 ){
      unusableMask |=  iMask;
      continue;
    }else if( op==SQLITE_INDEX_CONSTRAINT_EQ ){
      idxNum |= iMask;
      aIdx[iCol] = i;
    }
  }
  if( aIdx[3]==0 ){
    /* Ignore OFFSET if LIMIT is omitted */
    idxNum &= ~0x60;
    aIdx[4] = 0;
  }
  for(i=0; i<7; i++){
    if( (j = aIdx[i])>=0 ){
      pIdxInfo->aConstraintUsage[j].argvIndex = ++nArg;
      pIdxInfo->aConstraintUsage[j].omit =
         !SQLITE_SERIES_CONSTRAINT_VERIFY || i>=3;
    }
  }
  /* The current generate_column() implementation requires at least one
  ** argument (the START value).  Legacy versions assumed START=0 if the
  ** first argument was omitted.  Compile with -DZERO_ARGUMENT_GENERATE_SERIES
  ** to obtain the legacy behavior */
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
  if( !bStartSeen ){
    sqlite3_free(pVTab->zErrMsg);
    pVTab->zErrMsg = sqlite3_mprintf(
        "first argument to \"generate_series()\" missing or unusable");
    return SQLITE_ERROR;
  }
#endif
  if( (unusableMask & ~idxNum)!=0 ){
    /* The start, stop, and step columns are inputs.  Therefore if there
    ** are unusable constraints on any of start, stop, or step then
    ** this plan is unusable */
    return SQLITE_CONSTRAINT;
  }
  if( (idxNum & 0x03)==0x03 ){
    /* Both start= and stop= boundaries are available.  This is the 
    ** the preferred case */
    pIdxInfo->estimatedCost = (double)(2 - ((idxNum&4)!=0));
    pIdxInfo->estimatedRows = 1000;
    if( pIdxInfo->nOrderBy>=1 && pIdxInfo->aOrderBy[0].iColumn==0 ){
      if( pIdxInfo->aOrderBy[0].desc ){
        idxNum |= 0x08;
      }else{
        idxNum |= 0x10;
      }
      pIdxInfo->orderByConsumed = 1;
    }
  }else if( (idxNum & 0x21)==0x21 ){
    /* We have start= and LIMIT */
    pIdxInfo->estimatedRows = 2500;
  }else{
    /* If either boundary is missing, we have to generate a huge span
    ** of numbers.  Make this case very expensive so that the query
    ** planner will work hard to avoid it. */
    pIdxInfo->estimatedRows = 2147483647;
  }
  pIdxInfo->idxNum = idxNum;
#ifdef SQLITE_INDEX_SCAN_HEX
  pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_HEX;
#endif
  return SQLITE_OK;
}

/*
** This following structure defines all the methods for the 
** generate_series virtual table.
*/
static const sqlite3_module seriesModule = {
  0,                         /* iVersion */
  0,                         /* xCreate */
  seriesConnect,             /* xConnect */
  seriesBestIndex,           /* xBestIndex */
  seriesDisconnect,          /* xDisconnect */
  0,                         /* xDestroy */
  seriesOpen,                /* xOpen - open a cursor */
  seriesClose,               /* xClose - close a cursor */
  seriesFilter,              /* xFilter - configure scan constraints */
  seriesNext,                /* xNext - advance a cursor */
  seriesEof,                 /* xEof - check for end of scan */
  seriesColumn,              /* xColumn - read data */
  seriesRowid,               /* xRowid - read data */
  0,                         /* xUpdate */
  0,                         /* xBegin */
  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
  0,                         /* xSavepoint */
  0,                         /* xRelease */
  0,                         /* xRollbackTo */
  0,                         /* xShadowName */
  0                          /* xIntegrity */
};

#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef _WIN32

#endif
int sqlite3_series_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( sqlite3_libversion_number()<3008012 && pzErrMsg!=0 ){
    *pzErrMsg = sqlite3_mprintf(
        "generate_series() requires SQLite 3.8.12 or later");
    return SQLITE_ERROR;
  }
  rc = sqlite3_create_module(db, "generate_series", &seriesModule, 0);
#endif
  return rc;
}
#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  return sqlite3_series_init(db, pzErrMsg, pApi);
}
#endif

/************************* End ext/misc/series.c ********************/
/************************* Begin ext/misc/regexp.c ******************/
/*
** 2012-11-13
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** The code in this file implements a compact but reasonably
** efficient regular-expression matcher for posix extended regular
** expressions against UTF8 text.
**
** This file is an SQLite extension.  It registers a single function
** named "regexp(A,B)" where A is the regular expression and B is the
** string to be matched.  By registering this function, SQLite will also
** then implement the "B regexp A" operator.  Note that with the function
** the regular expression comes first, but with the operator it comes
** second.
**
**  The following regular expression syntax is supported:
**
**     X*      zero or more occurrences of X
**     X+      one or more occurrences of X
**     X?      zero or one occurrences of X
**     X{p,q}  between p and q occurrences of X
**     (X)     match X
**     X|Y     X or Y
**     ^X      X occurring at the beginning of the string
**     X$      X occurring at the end of the string
**     .       Match any single character
**     \c      Character c where c is one of \{}()[]|*+?-.
**     \c      C-language escapes for c in afnrtv.  ex: \t or \n
**     \uXXXX  Where XXXX is exactly 4 hex digits, unicode value XXXX
**     \xXX    Where XX is exactly 2 hex digits, unicode value XX
**     [abc]   Any single character from the set abc
**     [^abc]  Any single character not in the set abc
**     [a-z]   Any single character in the range a-z
**     [^a-z]  Any single character not in the range a-z
**     \b      Word boundary
**     \w      Word character.  [A-Za-z0-9_]
**     \W      Non-word character
**     \d      Digit
**     \D      Non-digit
**     \s      Whitespace character
**     \S      Non-whitespace character
**
** A nondeterministic finite automaton (NFA) is used for matching, so the
** performance is bounded by O(N*M) where N is the size of the regular
** expression and M is the size of the input string.  The matcher never
** exhibits exponential behavior.  Note that the X{p,q} operator expands
** to p copies of X following by q-p copies of X? and that the size of the
** regular expression in the O(N*M) performance bound is computed after
** this expansion.
**
** To help prevent DoS attacks, the maximum size of the NFA is restricted.
*/
#include <string.h>
#include <stdlib.h>
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1

/*
** The following #defines change the names of some functions implemented in
** this file to prevent name collisions with C-library functions of the
** same name.
*/
#define re_match   sqlite3re_match
#define re_compile sqlite3re_compile
#define re_free    sqlite3re_free

/* The end-of-input character */
#define RE_EOF            0    /* End of input */
#define RE_START  0xfffffff    /* Start of input - larger than an UTF-8 */

/* The NFA is implemented as sequence of opcodes taken from the following
** set.  Each opcode has a single integer argument.
*/
#define RE_OP_MATCH       1    /* Match the one character in the argument */
#define RE_OP_ANY         2    /* Match any one character.  (Implements ".") */
#define RE_OP_ANYSTAR     3    /* Special optimized version of .* */
#define RE_OP_FORK        4    /* Continue to both next and opcode at iArg */
#define RE_OP_GOTO        5    /* Jump to opcode at iArg */
#define RE_OP_ACCEPT      6    /* Halt and indicate a successful match */
#define RE_OP_CC_INC      7    /* Beginning of a [...] character class */
#define RE_OP_CC_EXC      8    /* Beginning of a [^...] character class */
#define RE_OP_CC_VALUE    9    /* Single value in a character class */
#define RE_OP_CC_RANGE   10    /* Range of values in a character class */
#define RE_OP_WORD       11    /* Perl word character [A-Za-z0-9_] */
#define RE_OP_NOTWORD    12    /* Not a perl word character */
#define RE_OP_DIGIT      13    /* digit:  [0-9] */
#define RE_OP_NOTDIGIT   14    /* Not a digit */
#define RE_OP_SPACE      15    /* space:  [ \t\n\r\v\f] */
#define RE_OP_NOTSPACE   16    /* Not a digit */
#define RE_OP_BOUNDARY   17    /* Boundary between word and non-word */
#define RE_OP_ATSTART    18    /* Currently at the start of the string */

/* Each opcode is a "state" in the NFA */
typedef unsigned short ReStateNumber;

/* Because this is an NFA and not a DFA, multiple states can be active at
** once.  An instance of the following object records all active states in
** the NFA.  The implementation is optimized for the common case where the
** number of actives states is small.
*/
typedef struct ReStateSet {
  unsigned nState;            /* Number of current states */
  ReStateNumber *aState;      /* Current states */
} ReStateSet;

/* An input string read one character at a time.
*/
typedef struct ReInput ReInput;
struct ReInput {
  const unsigned char *z;  /* All text */
  int i;                   /* Next byte to read */
  int mx;                  /* EOF when i>=mx */
};

/* A compiled NFA (or an NFA that is in the process of being compiled) is
** an instance of the following object.
*/
typedef struct ReCompiled ReCompiled;
struct ReCompiled {
  ReInput sIn;                /* Regular expression text */
  const char *zErr;           /* Error message to return */
  char *aOp;                  /* Operators for the virtual machine */
  int *aArg;                  /* Arguments to each operator */
  unsigned (*xNextChar)(ReInput*);  /* Next character function */
  unsigned char zInit[12];    /* Initial text to match */
  int nInit;                  /* Number of bytes in zInit */
  unsigned nState;            /* Number of entries in aOp[] and aArg[] */
  unsigned nAlloc;            /* Slots allocated for aOp[] and aArg[] */
  unsigned mxAlloc;           /* Complexity limit */
};

/* Add a state to the given state set if it is not already there */
static void re_add_state(ReStateSet *pSet, int newState){
  unsigned i;
  for(i=0; i<pSet->nState; i++) if( pSet->aState[i]==newState ) return;
  pSet->aState[pSet->nState++] = (ReStateNumber)newState;
}

/* Extract the next unicode character from *pzIn and return it.  Advance
** *pzIn to the first byte past the end of the character returned.  To
** be clear:  this routine converts utf8 to unicode.  This routine is 
** optimized for the common case where the next character is a single byte.
*/
static unsigned re_next_char(ReInput *p){
  unsigned c;
  if( p->i>=p->mx ) return 0;
  c = p->z[p->i++];
  if( c>=0x80 ){
    if( (c&0xe0)==0xc0 && p->i<p->mx && (p->z[p->i]&0xc0)==0x80 ){
      c = (c&0x1f)<<6 | (p->z[p->i++]&0x3f);
      if( c<0x80 ) c = 0xfffd;
    }else if( (c&0xf0)==0xe0 && p->i+1<p->mx && (p->z[p->i]&0xc0)==0x80
           && (p->z[p->i+1]&0xc0)==0x80 ){
      c = (c&0x0f)<<12 | ((p->z[p->i]&0x3f)<<6) | (p->z[p->i+1]&0x3f);
      p->i += 2;
      if( c<=0x7ff || (c>=0xd800 && c<=0xdfff) ) c = 0xfffd;
    }else if( (c&0xf8)==0xf0 && p->i+2<p->mx && (p->z[p->i]&0xc0)==0x80
           && (p->z[p->i+1]&0xc0)==0x80 && (p->z[p->i+2]&0xc0)==0x80 ){
      c = (c&0x07)<<18 | ((p->z[p->i]&0x3f)<<12) | ((p->z[p->i+1]&0x3f)<<6)
                       | (p->z[p->i+2]&0x3f);
      p->i += 3;
      if( c<=0xffff || c>0x10ffff ) c = 0xfffd;
    }else{
      c = 0xfffd;
    }
  }
  return c;
}
static unsigned re_next_char_nocase(ReInput *p){
  unsigned c = re_next_char(p);
  if( c>='A' && c<='Z' ) c += 'a' - 'A';
  return c;
}

/* Return true if c is a perl "word" character:  [A-Za-z0-9_] */
static int re_word_char(int c){
  return (c>='0' && c<='9') || (c>='a' && c<='z')
      || (c>='A' && c<='Z') || c=='_';
}

/* Return true if c is a "digit" character:  [0-9] */
static int re_digit_char(int c){
  return (c>='0' && c<='9');
}

/* Return true if c is a perl "space" character:  [ \t\r\n\v\f] */
static int re_space_char(int c){
  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
}

/* Run a compiled regular expression on the zero-terminated input
** string zIn[].  Return true on a match and false if there is no match.
*/
int re_match(ReCompiled *pRe, const unsigned char *zIn, int nIn){
  ReStateSet aStateSet[2], *pThis, *pNext;
  ReStateNumber aSpace[100];
  ReStateNumber *pToFree;
  unsigned int i = 0;
  unsigned int iSwap = 0;
  int c = RE_START;
  int cPrev = 0;
  int rc = 0;
  ReInput in;

  in.z = zIn;
  in.i = 0;
  in.mx = nIn>=0 ? nIn : (int)strlen((char const*)zIn);

  /* Look for the initial prefix match, if there is one. */
  if( pRe->nInit ){
    unsigned char x = pRe->zInit[0];
    while( in.i+pRe->nInit<=in.mx 
     && (zIn[in.i]!=x ||
         strncmp((const char*)zIn+in.i, (const char*)pRe->zInit, pRe->nInit)!=0)
    ){
      in.i++;
    }
    if( in.i+pRe->nInit>in.mx ) return 0;
    c = RE_START-1;
  }

  if( pRe->nState<=(sizeof(aSpace)/(sizeof(aSpace[0])*2)) ){
    pToFree = 0;
    aStateSet[0].aState = aSpace;
  }else{
    pToFree = sqlite3_malloc( sizeof(ReStateNumber)*2*pRe->nState );
    if( pToFree==0 ) return -1;
    aStateSet[0].aState = pToFree;
  }
  aStateSet[1].aState = &aStateSet[0].aState[pRe->nState];
  pNext = &aStateSet[1];
  pNext->nState = 0;
  re_add_state(pNext, 0);
  while( c!=RE_EOF && pNext->nState>0 ){
    cPrev = c;
    c = pRe->xNextChar(&in);
    pThis = pNext;
    pNext = &aStateSet[iSwap];
    iSwap = 1 - iSwap;
    pNext->nState = 0;
    for(i=0; i<pThis->nState; i++){
      int x = pThis->aState[i];
      switch( pRe->aOp[x] ){
        case RE_OP_MATCH: {
          if( pRe->aArg[x]==c ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_ATSTART: {
          if( cPrev==RE_START ) re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_ANY: {
          if( c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_WORD: {
          if( re_word_char(c) ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_NOTWORD: {
          if( !re_word_char(c) && c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_DIGIT: {
          if( re_digit_char(c) ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_NOTDIGIT: {
          if( !re_digit_char(c) && c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_SPACE: {
          if( re_space_char(c) ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_NOTSPACE: {
          if( !re_space_char(c) && c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_BOUNDARY: {
          if( re_word_char(c)!=re_word_char(cPrev) ) re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_ANYSTAR: {
          re_add_state(pNext, x);
          re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_FORK: {
          re_add_state(pThis, x+pRe->aArg[x]);
          re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_GOTO: {
          re_add_state(pThis, x+pRe->aArg[x]);
          break;
        }
        case RE_OP_ACCEPT: {
          rc = 1;
          goto re_match_end;
        }
        case RE_OP_CC_EXC: {
          if( c==0 ) break;
          /* fall-through */ goto re_op_cc_inc;
        }
        case RE_OP_CC_INC: re_op_cc_inc: {
          int j = 1;
          int n = pRe->aArg[x];
          int hit = 0;
          for(j=1; j>0 && j<n; j++){
            if( pRe->aOp[x+j]==RE_OP_CC_VALUE ){
              if( pRe->aArg[x+j]==c ){
                hit = 1;
                j = -1;
              }
            }else{
              if( pRe->aArg[x+j]<=c && pRe->aArg[x+j+1]>=c ){
                hit = 1;
                j = -1;
              }else{
                j++;
              }
            }
          }
          if( pRe->aOp[x]==RE_OP_CC_EXC ) hit = !hit;
          if( hit ) re_add_state(pNext, x+n);
          break;
        }
      }
    }
  }
  for(i=0; i<pNext->nState; i++){
    int x = pNext->aState[i];
    while( pRe->aOp[x]==RE_OP_GOTO ) x += pRe->aArg[x];
    if( pRe->aOp[x]==RE_OP_ACCEPT ){ rc = 1; break; }
  }
re_match_end:
  sqlite3_free(pToFree);
  return rc;
}

/* Resize the opcode and argument arrays for an RE under construction.
*/
static int re_resize(ReCompiled *p, unsigned int N){
  char *aOp;
  int *aArg;
  if( N>p->mxAlloc ){ p->zErr = "REGEXP pattern too big"; return 1; }
  aOp = sqlite3_realloc64(p->aOp, N*sizeof(p->aOp[0]));
  if( aOp==0 ){ p->zErr = "out of memory"; return 1; }
  p->aOp = aOp;
  aArg = sqlite3_realloc64(p->aArg, N*sizeof(p->aArg[0]));
  if( aArg==0 ){ p->zErr = "out of memory"; return 1; }
  p->aArg = aArg;
  p->nAlloc = N;
  return 0;
}

/* Insert a new opcode and argument into an RE under construction.  The
** insertion point is just prior to existing opcode iBefore.
*/
static int re_insert(ReCompiled *p, int iBefore, int op, int arg){
  int i;
  if( p->nAlloc<=p->nState && re_resize(p, p->nAlloc*2) ) return 0;
  for(i=p->nState; i>iBefore; i--){
    p->aOp[i] = p->aOp[i-1];
    p->aArg[i] = p->aArg[i-1];
  }
  p->nState++;
  p->aOp[iBefore] = (char)op;
  p->aArg[iBefore] = arg;
  return iBefore;
}

/* Append a new opcode and argument to the end of the RE under construction.
*/
static int re_append(ReCompiled *p, int op, int arg){
  return re_insert(p, p->nState, op, arg);
}

/* Make a copy of N opcodes starting at iStart onto the end of the RE
** under construction.
*/
static void re_copy(ReCompiled *p, int iStart, unsigned int N){
  if( p->nState+N>=p->nAlloc && re_resize(p, p->nAlloc*2+N) ) return;
  memcpy(&p->aOp[p->nState], &p->aOp[iStart], N*sizeof(p->aOp[0]));
  memcpy(&p->aArg[p->nState], &p->aArg[iStart], N*sizeof(p->aArg[0]));
  p->nState += N;
}

/* Return true if c is a hexadecimal digit character:  [0-9a-fA-F]
** If c is a hex digit, also set *pV = (*pV)*16 + valueof(c).  If
** c is not a hex digit *pV is unchanged.
*/
static int re_hex(int c, int *pV){
  if( c>='0' && c<='9' ){
    c -= '0';
  }else if( c>='a' && c<='f' ){
    c -= 'a' - 10;
  }else if( c>='A' && c<='F' ){
    c -= 'A' - 10;
  }else{
    return 0;
  }
  *pV = (*pV)*16 + (c & 0xff);
  return 1;
}

/* A backslash character has been seen, read the next character and
** return its interpretation.
*/
static unsigned re_esc_char(ReCompiled *p){
  static const char zEsc[] = "afnrtv\\()*.+?[$^{|}]-";
  static const char zTrans[] = "\a\f\n\r\t\v";
  int i, v = 0;
  char c;
  if( p->sIn.i>=p->sIn.mx ) return 0;
  c = p->sIn.z[p->sIn.i];
  if( c=='u' && p->sIn.i+4<p->sIn.mx ){
    const unsigned char *zIn = p->sIn.z + p->sIn.i;
    if( re_hex(zIn[1],&v)
     && re_hex(zIn[2],&v)
     && re_hex(zIn[3],&v)
     && re_hex(zIn[4],&v)
    ){
      p->sIn.i += 5;
      return v;
    }
  }
  if( c=='x' && p->sIn.i+2<p->sIn.mx ){
    const unsigned char *zIn = p->sIn.z + p->sIn.i;
    if( re_hex(zIn[1],&v)
     && re_hex(zIn[2],&v)
    ){
      p->sIn.i += 3;
      return v;
    }
  }
  for(i=0; zEsc[i] && zEsc[i]!=c; i++){}
  if( zEsc[i] ){
    if( i<6 ) c = zTrans[i];
    p->sIn.i++;
  }else{
    p->zErr = "unknown \\ escape";
  }
  return c;
}

/* Forward declaration */
static const char *re_subcompile_string(ReCompiled*);

/* Peek at the next byte of input */
static unsigned char rePeek(ReCompiled *p){
  return p->sIn.i<p->sIn.mx ? p->sIn.z[p->sIn.i] : 0;
}

/* Compile RE text into a sequence of opcodes.  Continue up to the
** first unmatched ")" character, then return.  If an error is found,
** return a pointer to the error message string.
*/
static const char *re_subcompile_re(ReCompiled *p){
  const char *zErr;
  int iStart, iEnd, iGoto;
  iStart = p->nState;
  zErr = re_subcompile_string(p);
  if( zErr ) return zErr;
  while( rePeek(p)=='|' ){
    iEnd = p->nState;
    re_insert(p, iStart, RE_OP_FORK, iEnd + 2 - iStart);
    iGoto = re_append(p, RE_OP_GOTO, 0);
    p->sIn.i++;
    zErr = re_subcompile_string(p);
    if( zErr ) return zErr;
    p->aArg[iGoto] = p->nState - iGoto;
  }
  return 0;
}

/* Compile an element of regular expression text (anything that can be
** an operand to the "|" operator).  Return NULL on success or a pointer
** to the error message if there is a problem.
*/
static const char *re_subcompile_string(ReCompiled *p){
  int iPrev = -1;
  int iStart;
  unsigned c;
  const char *zErr;
  while( (c = p->xNextChar(&p->sIn))!=0 ){
    iStart = p->nState;
    switch( c ){
      case '|':
      case ')': {
        p->sIn.i--;
        return 0;
      }
      case '(': {
        zErr = re_subcompile_re(p);
        if( zErr ) return zErr;
        if( rePeek(p)!=')' ) return "unmatched '('";
        p->sIn.i++;
        break;
      }
      case '.': {
        if( rePeek(p)=='*' ){
          re_append(p, RE_OP_ANYSTAR, 0);
          p->sIn.i++;
        }else{
          re_append(p, RE_OP_ANY, 0);
        }
        break;
      }
      case '*': {
        if( iPrev<0 ) return "'*' without operand";
        re_insert(p, iPrev, RE_OP_GOTO, p->nState - iPrev + 1);
        re_append(p, RE_OP_FORK, iPrev - p->nState + 1);
        break;
      }
      case '+': {
        if( iPrev<0 ) return "'+' without operand";
        re_append(p, RE_OP_FORK, iPrev - p->nState);
        break;
      }
      case '?': {
        if( iPrev<0 ) return "'?' without operand";
        re_insert(p, iPrev, RE_OP_FORK, p->nState - iPrev+1);
        break;
      }
      case '$': {
        re_append(p, RE_OP_MATCH, RE_EOF);
        break;
      }
      case '^': {
        re_append(p, RE_OP_ATSTART, 0);
        break;
      }
      case '{': {
        unsigned int m = 0, n = 0;
        unsigned int sz, j;
        if( iPrev<0 ) return "'{m,n}' without operand";
        while( (c=rePeek(p))>='0' && c<='9' ){
          m = m*10 + c - '0';
          if( m*2>p->mxAlloc ) return "REGEXP pattern too big";
          p->sIn.i++;
        }
        n = m;
        if( c==',' ){
          p->sIn.i++;
          n = 0;
          while( (c=rePeek(p))>='0' && c<='9' ){
            n = n*10 + c-'0';
            if( n*2>p->mxAlloc ) return "REGEXP pattern too big";
            p->sIn.i++;
          }
        }
        if( c!='}' ) return "unmatched '{'";
        if( n<m ) return "n less than m in '{m,n}'";
        p->sIn.i++;
        sz = p->nState - iPrev;
        if( m==0 ){
          if( n==0 ) return "both m and n are zero in '{m,n}'";
          re_insert(p, iPrev, RE_OP_FORK, sz+1);
          iPrev++;
          n--;
        }else{
          for(j=1; j<m; j++) re_copy(p, iPrev, sz);
        }
        for(j=m; j<n; j++){
          re_append(p, RE_OP_FORK, sz+1);
          re_copy(p, iPrev, sz);
        }
        if( n==0 && m>0 ){
          re_append(p, RE_OP_FORK, -(int)sz);
        }
        break;
      }
      case '[': {
        unsigned int iFirst = p->nState;
        if( rePeek(p)=='^' ){
          re_append(p, RE_OP_CC_EXC, 0);
          p->sIn.i++;
        }else{
          re_append(p, RE_OP_CC_INC, 0);
        }
        while( (c = p->xNextChar(&p->sIn))!=0 ){
          if( c=='[' && rePeek(p)==':' ){
            return "POSIX character classes not supported";
          }
          if( c=='\\' ) c = re_esc_char(p);
          if( rePeek(p)=='-' ){
            re_append(p, RE_OP_CC_RANGE, c);
            p->sIn.i++;
            c = p->xNextChar(&p->sIn);
            if( c=='\\' ) c = re_esc_char(p);
            re_append(p, RE_OP_CC_RANGE, c);
          }else{
            re_append(p, RE_OP_CC_VALUE, c);
          }
          if( rePeek(p)==']' ){ p->sIn.i++; break; }
        }
        if( c==0 ) return "unclosed '['";
        if( p->nState>iFirst ) p->aArg[iFirst] = p->nState - iFirst;
        break;
      }
      case '\\': {
        int specialOp = 0;
        switch( rePeek(p) ){
          case 'b': specialOp = RE_OP_BOUNDARY;   break;
          case 'd': specialOp = RE_OP_DIGIT;      break;
          case 'D': specialOp = RE_OP_NOTDIGIT;   break;
          case 's': specialOp = RE_OP_SPACE;      break;
          case 'S': specialOp = RE_OP_NOTSPACE;   break;
          case 'w': specialOp = RE_OP_WORD;       break;
          case 'W': specialOp = RE_OP_NOTWORD;    break;
        }
        if( specialOp ){
          p->sIn.i++;
          re_append(p, specialOp, 0);
        }else{
          c = re_esc_char(p);
          re_append(p, RE_OP_MATCH, c);
        }
        break;
      }
      default: {
        re_append(p, RE_OP_MATCH, c);
        break;
      }
    }
    iPrev = iStart;
  }
  return 0;
}

/* Free and reclaim all the memory used by a previously compiled
** regular expression.  Applications should invoke this routine once
** for every call to re_compile() to avoid memory leaks.
*/
static void re_free(ReCompiled *pRe){
  if( pRe ){
    sqlite3_free(pRe->aOp);
    sqlite3_free(pRe->aArg);
    sqlite3_free(pRe);
  }
}

/*
** Version of re_free() that accepts a pointer of type (void*). Required
** to satisfy sanitizers when the re_free() function is called via a
** function pointer.
*/
static void re_free_voidptr(void *p){
  re_free((ReCompiled*)p);
}

/*
** Compile a textual regular expression in zIn[] into a compiled regular
** expression suitable for us by re_match() and return a pointer to the
** compiled regular expression in *ppRe.  Return NULL on success or an
** error message if something goes wrong.
*/
static const char *re_compile(
  ReCompiled **ppRe,      /* OUT: write compiled NFA here */
  const char *zIn,        /* Input regular expression */
  int mxRe,               /* Complexity limit */
  int noCase              /* True for caseless comparisons */
){
  ReCompiled *pRe;
  const char *zErr;
  int i, j;

  *ppRe = 0;
  pRe = sqlite3_malloc64( sizeof(*pRe) );
  if( pRe==0 ){
    return "out of memory";
  }
  memset(pRe, 0, sizeof(*pRe));
  pRe->xNextChar = noCase ? re_next_char_nocase : re_next_char;
  pRe->mxAlloc = mxRe;
  if( re_resize(pRe, 30) ){
    zErr = pRe->zErr;
    re_free(pRe);
    return zErr;
  }
  if( zIn[0]=='^' ){
    zIn++;
  }else{
    re_append(pRe, RE_OP_ANYSTAR, 0);
  }
  pRe->sIn.z = (unsigned char*)zIn;
  pRe->sIn.i = 0;
  pRe->sIn.mx = (int)strlen(zIn);
  zErr = re_subcompile_re(pRe);
  if( zErr ){
    re_free(pRe);
    return zErr;
  }
  if( pRe->sIn.i>=pRe->sIn.mx ){
    re_append(pRe, RE_OP_ACCEPT, 0);
    *ppRe = pRe;
  }else{
    re_free(pRe);
    return "unrecognized character";
  }

  /* The following is a performance optimization.  If the regex begins with
  ** ".*" (if the input regex lacks an initial "^") and afterwards there are
  ** one or more matching characters, enter those matching characters into
  ** zInit[].  The re_match() routine can then search ahead in the input 
  ** string looking for the initial match without having to run the whole
  ** regex engine over the string.  Do not worry about trying to match
  ** unicode characters beyond plane 0 - those are very rare and this is
  ** just an optimization. */
  if( pRe->aOp[0]==RE_OP_ANYSTAR && !noCase ){
    for(j=0, i=1; j<(int)sizeof(pRe->zInit)-2 && pRe->aOp[i]==RE_OP_MATCH; i++){
      unsigned x = pRe->aArg[i];
      if( x<=0x7f ){
        pRe->zInit[j++] = (unsigned char)x;
      }else if( x<=0x7ff ){
        pRe->zInit[j++] = (unsigned char)(0xc0 | (x>>6));
        pRe->zInit[j++] = 0x80 | (x&0x3f);
      }else if( x<=0xffff ){
        pRe->zInit[j++] = (unsigned char)(0xe0 | (x>>12));
        pRe->zInit[j++] = 0x80 | ((x>>6)&0x3f);
        pRe->zInit[j++] = 0x80 | (x&0x3f);
      }else{
        break;
      }
    }
    if( j>0 && pRe->zInit[j-1]==0 ) j--;
    pRe->nInit = j;
  }
  return pRe->zErr;
}

/*
** The value of LIMIT_MAX_PATTERN_LENGTH.
*/
static int re_maxlen(sqlite3_context *context){
  sqlite3 *db = sqlite3_context_db_handle(context);
  return sqlite3_limit(db, SQLITE_LIMIT_LIKE_PATTERN_LENGTH,-1);
}

/*
** Maximum NFA size given a maximum pattern length.
*/
static int re_maxnfa(int mxlen){
  return 75+mxlen/2;
}

/*
** Implementation of the regexp() SQL function.  This function implements
** the build-in REGEXP operator.  The first argument to the function is the
** pattern and the second argument is the string.  So, the SQL statements:
**
**       A REGEXP B
**
** is implemented as regexp(B,A).
*/
static void re_sql_func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  ReCompiled *pRe;          /* Compiled regular expression */
  const char *zPattern;     /* The regular expression */
  const unsigned char *zStr;/* String being searched */
  const char *zErr;         /* Compile error message */
  int setAux = 0;           /* True to invoke sqlite3_set_auxdata() */

  (void)argc;  /* Unused */
  pRe = sqlite3_get_auxdata(context, 0);
  if( pRe==0 ){
    int mxLen = re_maxlen(context);
    int nPattern;
    zPattern = (const char*)sqlite3_value_text(argv[0]);
    if( zPattern==0 ) return;
    nPattern = sqlite3_value_bytes(argv[0]);
    if( nPattern>mxLen ){
      zErr = "REGEXP pattern too big";
    }else{
      zErr = re_compile(&pRe, zPattern, re_maxnfa(mxLen),
                        sqlite3_user_data(context)!=0);
    }
    if( zErr ){
      re_free(pRe);
      sqlite3_result_error(context, zErr, -1);
      return;
    }
    if( pRe==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
    setAux = 1;
  }
  zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
  if( zStr!=0 ){
    sqlite3_result_int(context, re_match(pRe, zStr, -1));
  }
  if( setAux ){
    sqlite3_set_auxdata(context, 0, pRe, re_free_voidptr);
  }
}

#if defined(SQLITE_DEBUG)
/*
** This function is used for testing and debugging only.  It is only available
** if the SQLITE_DEBUG compile-time option is used.
**
** Compile a regular expression and then convert the compiled expression into
** text and return that text.
*/
static void re_bytecode_func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zPattern;
  const char *zErr;
  ReCompiled *pRe;
  sqlite3_str *pStr;
  int i;
  int n;
  char *z;
  static const char *ReOpName[] = {
    "EOF",
    "MATCH",
    "ANY",
    "ANYSTAR",
    "FORK",
    "GOTO",
    "ACCEPT",
    "CC_INC",
    "CC_EXC",
    "CC_VALUE",
    "CC_RANGE",
    "WORD",
    "NOTWORD",
    "DIGIT",
    "NOTDIGIT",
    "SPACE",
    "NOTSPACE",
    "BOUNDARY",
    "ATSTART",
  };

  (void)argc;
  zPattern = (const char*)sqlite3_value_text(argv[0]);
  if( zPattern==0 ) return;
  zErr = re_compile(&pRe, zPattern, re_maxnfa(re_maxlen(context)),
                    sqlite3_user_data(context)!=0);
  if( zErr ){
    re_free(pRe);
    sqlite3_result_error(context, zErr, -1);
    return;
  }
  if( pRe==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }
  pStr = sqlite3_str_new(0);
  if( pStr==0 ) goto re_bytecode_func_err;
  if( pRe->nInit>0 ){
    sqlite3_str_appendf(pStr, "INIT     ");
    for(i=0; i<pRe->nInit; i++){
      sqlite3_str_appendf(pStr, "%02x", pRe->zInit[i]);
    }
    sqlite3_str_appendf(pStr, "\n");
  }
  for(i=0; (unsigned)i<pRe->nState; i++){
    sqlite3_str_appendf(pStr, "%-8s %4d\n",
         ReOpName[(unsigned char)pRe->aOp[i]], pRe->aArg[i]);
  }
  n = sqlite3_str_length(pStr);
  z = sqlite3_str_finish(pStr);
  if( n==0 ){
    sqlite3_free(z);
  }else{
    sqlite3_result_text(context, z, n-1, sqlite3_free);
  }

re_bytecode_func_err:
  re_free(pRe);
}

#endif /* SQLITE_DEBUG */


/*
** Invoke this routine to register the regexp() function with the
** SQLite database connection.
*/
#ifdef _WIN32

#endif
int sqlite3_regexp_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused */
  rc = sqlite3_create_function(db, "regexp", 2, 
                            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                            0, re_sql_func, 0, 0);
  if( rc==SQLITE_OK ){
    /* The regexpi(PATTERN,STRING) function is a case-insensitive version
    ** of regexp(PATTERN,STRING). */
    rc = sqlite3_create_function(db, "regexpi", 2,
                            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                            (void*)db, re_sql_func, 0, 0);
#if defined(SQLITE_DEBUG)
    if( rc==SQLITE_OK ){
      rc = sqlite3_create_function(db, "regexp_bytecode", 1,
                            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                            0, re_bytecode_func, 0, 0);
    }
#endif /* SQLITE_DEBUG */
  }
  return rc;
}
#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db, 
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  rc = sqlite3_create_function(db, "regexp", 2, SQLITE_UTF8, 0,
                                 re_sql_func, 0, 0);
  return rc;
}
#endif

/************************* End ext/misc/regexp.c ********************/
#ifndef SQLITE_SHELL_FIDDLE
/************************* Begin ext/misc/fileio.c ******************/
/*
** 2014-06-13
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements SQL functions readfile() and
** writefile(), and eponymous virtual type "fsdir".
**
** WRITEFILE(FILE, DATA [, MODE [, MTIME]]):
**
**   If neither of the optional arguments is present, then this UDF
**   function writes blob DATA to file FILE. If successful, the number
**   of bytes written is returned. If an error occurs, NULL is returned.
**
**   If the first option argument - MODE - is present, then it must
**   be passed an integer value that corresponds to a POSIX mode
**   value (file type + permissions, as returned in the stat.st_mode
**   field by the stat() system call). Three types of files may
**   be written/created:
**
**     regular files:  (mode & 0170000)==0100000
**     symbolic links: (mode & 0170000)==0120000
**     directories:    (mode & 0170000)==0040000
**
**   For a directory, the DATA is ignored. For a symbolic link, it is
**   interpreted as text and used as the target of the link. For a
**   regular file, it is interpreted as a blob and written into the
**   named file. Regardless of the type of file, its permissions are
**   set to (mode & 0777) before returning.
**
**   If the optional MTIME argument is present, then it is interpreted
**   as an integer - the number of seconds since the unix epoch. The
**   modification-time of the target file is set to this value before
**   returning.
**
**   If five or more arguments are passed to this function and an
**   error is encountered, an exception is raised.
**
** READFILE(FILE):
**
**   Read and return the contents of file FILE (type blob) from disk.
**
** FSDIR:
**
**   Used as follows:
**
**     SELECT * FROM fsdir($path [, $dir]);
**
**   Parameter $path is an absolute or relative pathname. If the file that it
**   refers to does not exist, it is an error. If the path refers to a regular
**   file or symbolic link, it returns a single row. Or, if the path refers
**   to a directory, it returns one row for the directory, and one row for each
**   file within the hierarchy rooted at $path.
**
**   Each row has the following columns:
**
**     name:  Path to file or directory (text value).
**     mode:  Value of stat.st_mode for directory entry (an integer).
**     mtime: Value of stat.st_mtime for directory entry (an integer).
**     data:  For a regular file, a blob containing the file data. For a
**            symlink, a text value containing the text of the link. For a
**            directory, NULL.
**     level: Directory hierarchy level.  Topmost is 1.
**
**   If a non-NULL value is specified for the optional $dir parameter and
**   $path is a relative path, then $path is interpreted relative to $dir. 
**   And the paths returned in the "name" column of the table are also 
**   relative to directory $dir.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <stdio.h>
#include <string.h>
#include <assert.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#if !defined(_WIN32) && !defined(WIN32)
#  include <unistd.h>
#  include <dirent.h>
#  include <utime.h>
#  include <sys/time.h>
#  define STRUCT_STAT struct stat
#  include <limits.h>
#  include <stdlib.h>
#else
/* #  include "windirent.h" */
#  include <direct.h>
#  define STRUCT_STAT struct _stat
#  define chmod(path,mode) fileio_chmod(path,mode)
#  define mkdir(path,mode) fileio_mkdir(path)
   extern LPWSTR sqlite3_win32_utf8_to_unicode(const char*);
   extern char *sqlite3_win32_unicode_to_utf8(LPCWSTR);
#endif
#include <time.h>
#include <errno.h>

/* When used as part of the CLI, the sqlite3_stdio.h module will have
** been included before this one. In that case use the sqlite3_stdio.h
** #defines.  If not, create our own for fopen().
*/
#ifndef _SQLITE3_STDIO_H_
# define sqlite3_fopen fopen
#endif

/*
** Structure of the fsdir() table-valued function
*/
                 /*    0    1    2     3    4     5           6          */
#define FSDIR_SCHEMA "(name,mode,mtime,data,level,path HIDDEN,dir HIDDEN)"

#define FSDIR_COLUMN_NAME     0     /* Name of the file */
#define FSDIR_COLUMN_MODE     1     /* Access mode */
#define FSDIR_COLUMN_MTIME    2     /* Last modification time */
#define FSDIR_COLUMN_DATA     3     /* File content */
#define FSDIR_COLUMN_LEVEL    4     /* Level.  Topmost is 1 */
#define FSDIR_COLUMN_PATH     5     /* Path to top of search */
#define FSDIR_COLUMN_DIR      6     /* Path is relative to this directory */

/*
** UTF8 chmod() function for Windows
*/
#if defined(_WIN32) || defined(WIN32)
static int fileio_chmod(const char *zPath, int pmode){
  int rc;
  wchar_t *b1 = sqlite3_win32_utf8_to_unicode(zPath);
  if( b1==0 ) return -1;
  rc = _wchmod(b1, pmode);
  sqlite3_free(b1);
  return rc;
}
#endif

/*
** UTF8 mkdir() function for Windows
*/
#if defined(_WIN32) || defined(WIN32)
static int fileio_mkdir(const char *zPath){
  int rc;
  wchar_t *b1 = sqlite3_win32_utf8_to_unicode(zPath);
  if( b1==0 ) return -1;
  rc = _wmkdir(b1);
  sqlite3_free(b1);
  return rc;
}
#endif


/*
** Set the result stored by context ctx to a blob containing the 
** contents of file zName.  Or, leave the result unchanged (NULL)
** if the file does not exist or is unreadable.
**
** If the file exceeds the SQLite blob size limit, through an
** SQLITE_TOOBIG error.
**
** Throw an SQLITE_IOERR if there are difficulties pulling the file
** off of disk.
*/
static void readFileContents(sqlite3_context *ctx, const char *zName){
  FILE *in;
  sqlite3_int64 nIn;
  void *pBuf;
  sqlite3 *db;
  int mxBlob;

  in = sqlite3_fopen(zName, "rb");
  if( in==0 ){
    /* File does not exist or is unreadable. Leave the result set to NULL. */
    return;
  }
  fseek(in, 0, SEEK_END);
  nIn = ftell(in);
  rewind(in);
  db = sqlite3_context_db_handle(ctx);
  mxBlob = sqlite3_limit(db, SQLITE_LIMIT_LENGTH, -1);
  if( nIn>mxBlob ){
    sqlite3_result_error_code(ctx, SQLITE_TOOBIG);
    fclose(in);
    return;
  }
  pBuf = sqlite3_malloc64( nIn ? nIn : 1 );
  if( pBuf==0 ){
    sqlite3_result_error_nomem(ctx);
    fclose(in);
    return;
  }
  if( nIn==(sqlite3_int64)fread(pBuf, 1, (size_t)nIn, in) ){
    sqlite3_result_blob64(ctx, pBuf, nIn, sqlite3_free);
  }else{
    sqlite3_result_error_code(ctx, SQLITE_IOERR);
    sqlite3_free(pBuf);
  }
  fclose(in);
}

/*
** Implementation of the "readfile(X)" SQL function.  The entire content
** of the file named X is read and returned as a BLOB.  NULL is returned
** if the file does not exist or is unreadable.
*/
static void readfileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zName;
  (void)(argc);  /* Unused parameter */
  zName = (const char*)sqlite3_value_text(argv[0]);
  if( zName==0 ) return;
  readFileContents(context, zName);
}

/*
** Set the error message contained in context ctx to the results of
** vprintf(zFmt, ...).
*/
static void ctxErrorMsg(sqlite3_context *ctx, const char *zFmt, ...){
  char *zMsg = 0;
  va_list ap;
  va_start(ap, zFmt);
  zMsg = sqlite3_vmprintf(zFmt, ap);
  sqlite3_result_error(ctx, zMsg, -1);
  sqlite3_free(zMsg);
  va_end(ap);
}

#if defined(_WIN32)
/*
** This function is designed to convert a Win32 FILETIME structure into the
** number of seconds since the Unix Epoch (1970-01-01 00:00:00 UTC).
*/
static sqlite3_uint64 fileTimeToUnixTime(
  LPFILETIME pFileTime
){
  SYSTEMTIME epochSystemTime;
  ULARGE_INTEGER epochIntervals;
  FILETIME epochFileTime;
  ULARGE_INTEGER fileIntervals;

  memset(&epochSystemTime, 0, sizeof(SYSTEMTIME));
  epochSystemTime.wYear = 1970;
  epochSystemTime.wMonth = 1;
  epochSystemTime.wDay = 1;
  SystemTimeToFileTime(&epochSystemTime, &epochFileTime);
  epochIntervals.LowPart = epochFileTime.dwLowDateTime;
  epochIntervals.HighPart = epochFileTime.dwHighDateTime;

  fileIntervals.LowPart = pFileTime->dwLowDateTime;
  fileIntervals.HighPart = pFileTime->dwHighDateTime;

  return (fileIntervals.QuadPart - epochIntervals.QuadPart) / 10000000;
}
#endif /* _WIN32 */

/*
** This function is used in place of stat().  On Windows, special handling
** is required in order for the included time to be returned as UTC.  On all
** other systems, this function simply calls stat().
*/
static int fileStat(
  const char *zPath,
  STRUCT_STAT *pStatBuf
){
#if defined(_WIN32)
  int rc;
  wchar_t *b1 = sqlite3_win32_utf8_to_unicode(zPath);
  if( b1==0 ) return 1;
  rc = _wstat(b1, pStatBuf);
  if( rc==0 ){
    HANDLE hFindFile;
    WIN32_FIND_DATAW fd;
    memset(&fd, 0, sizeof(WIN32_FIND_DATAW));
    hFindFile = FindFirstFileW(b1, &fd);
    if( hFindFile!=NULL ){
      pStatBuf->st_ctime = (time_t)fileTimeToUnixTime(&fd.ftCreationTime);
      pStatBuf->st_atime = (time_t)fileTimeToUnixTime(&fd.ftLastAccessTime);
      pStatBuf->st_mtime = (time_t)fileTimeToUnixTime(&fd.ftLastWriteTime);
      FindClose(hFindFile);
    }
  }
  sqlite3_free(b1);
  return rc;
#else
  return stat(zPath, pStatBuf);
#endif
}

/*
** This function is used in place of lstat().  On Windows, special handling
** is required in order for the included time to be returned as UTC.  On all
** other systems, this function simply calls lstat().
*/
static int fileLinkStat(
  const char *zPath,
  STRUCT_STAT *pStatBuf
){
#if defined(_WIN32)
  return fileStat(zPath, pStatBuf);
#else
  return lstat(zPath, pStatBuf);
#endif
}

/*
** Argument zFile is the name of a file that will be created and/or written
** by SQL function writefile(). This function ensures that the directory
** zFile will be written to exists, creating it if required. The permissions
** for any path components created by this function are set in accordance
** with the current umask.
**
** If an OOM condition is encountered, SQLITE_NOMEM is returned. Otherwise,
** SQLITE_OK is returned if the directory is successfully created, or
** SQLITE_ERROR otherwise.
*/
static int makeDirectory(
  const char *zFile
){
  char *zCopy = sqlite3_mprintf("%s", zFile);
  int rc = SQLITE_OK;

  if( zCopy==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int nCopy = (int)strlen(zCopy);
    int i = 1;

    while( rc==SQLITE_OK ){
      STRUCT_STAT sStat;
      int rc2;

      for(; zCopy[i]!='/' && i<nCopy; i++);
      if( i==nCopy ) break;
      zCopy[i] = '\0';

      rc2 = fileStat(zCopy, &sStat);
      if( rc2!=0 ){
        if( mkdir(zCopy, 0777) ) rc = SQLITE_ERROR;
      }else{
        if( !S_ISDIR(sStat.st_mode) ) rc = SQLITE_ERROR;
      }
      zCopy[i] = '/';
      i++;
    }

    sqlite3_free(zCopy);
  }

  return rc;
}

/*
** This function does the work for the writefile() UDF. Refer to 
** header comments at the top of this file for details.
*/
static int writeFile(
  sqlite3_context *pCtx,          /* Context to return bytes written in */
  const char *zFile,              /* File to write */
  sqlite3_value *pData,           /* Data to write */
  mode_t mode,                    /* MODE parameter passed to writefile() */
  sqlite3_int64 mtime             /* MTIME parameter (or -1 to not set time) */
){
  if( zFile==0 ) return 1;
#if !defined(_WIN32) && !defined(WIN32)
  if( S_ISLNK(mode) ){
    const char *zTo = (const char*)sqlite3_value_text(pData);
    if( zTo==0 ) return 1;
    unlink(zFile);
    if( symlink(zTo, zFile)<0 ) return 1;
  }else
#endif
  {
    if( S_ISDIR(mode) ){
      if( mkdir(zFile, mode) ){
        /* The mkdir() call to create the directory failed. This might not
        ** be an error though - if there is already a directory at the same
        ** path and either the permissions already match or can be changed
        ** to do so using chmod(), it is not an error.  */
        STRUCT_STAT sStat;
        if( errno!=EEXIST
         || 0!=fileStat(zFile, &sStat)
         || !S_ISDIR(sStat.st_mode)
         || ((sStat.st_mode&0777)!=(mode&0777) && 0!=chmod(zFile, mode&0777))
        ){
          return 1;
        }
      }
    }else{
      sqlite3_int64 nWrite = 0;
      const char *z;
      int rc = 0;
      FILE *out = sqlite3_fopen(zFile, "wb");
      if( out==0 ) return 1;
      z = (const char*)sqlite3_value_blob(pData);
      if( z ){
        sqlite3_int64 n = fwrite(z, 1, sqlite3_value_bytes(pData), out);
        nWrite = sqlite3_value_bytes(pData);
        if( nWrite!=n ){
          rc = 1;
        }
      }
      fclose(out);
      if( rc==0 && mode && chmod(zFile, mode & 0777) ){
        rc = 1;
      }
      if( rc ) return 2;
      sqlite3_result_int64(pCtx, nWrite);
    }
  }

  if( mtime>=0 ){
#if defined(_WIN32)
    /* Windows */
    FILETIME lastAccess;
    FILETIME lastWrite;
    SYSTEMTIME currentTime;
    LONGLONG intervals;
    HANDLE hFile;
    LPWSTR zUnicodeName;
    extern LPWSTR sqlite3_win32_utf8_to_unicode(const char*);

    GetSystemTime(&currentTime);
    SystemTimeToFileTime(&currentTime, &lastAccess);
    intervals = (mtime*10000000) + 116444736000000000;
    lastWrite.dwLowDateTime = (DWORD)intervals;
    lastWrite.dwHighDateTime = intervals >> 32;
    zUnicodeName = sqlite3_win32_utf8_to_unicode(zFile);
    if( zUnicodeName==0 ){
      return 1;
    }
    hFile = CreateFileW(
      zUnicodeName, FILE_WRITE_ATTRIBUTES, 0, NULL, OPEN_EXISTING,
      FILE_FLAG_BACKUP_SEMANTICS, NULL
    );
    sqlite3_free(zUnicodeName);
    if( hFile!=INVALID_HANDLE_VALUE ){
      BOOL bResult = SetFileTime(hFile, NULL, &lastAccess, &lastWrite);
      CloseHandle(hFile);
      return !bResult;
    }else{
      return 1;
    }
#elif defined(AT_FDCWD) && 0 /* utimensat() is not universally available */
    /* Recent unix */
    struct timespec times[2];
    times[0].tv_nsec = times[1].tv_nsec = 0;
    times[0].tv_sec = time(0);
    times[1].tv_sec = mtime;
    if( utimensat(AT_FDCWD, zFile, times, AT_SYMLINK_NOFOLLOW) ){
      return 1;
    }
#else
    /* Legacy unix. 
    **
    ** Do not use utimes() on a symbolic link - it sees through the link and
    ** modifies the timestamps on the target. Or fails if the target does 
    ** not exist.  */
    if( 0==S_ISLNK(mode) ){
      struct timeval times[2];
      times[0].tv_usec = times[1].tv_usec = 0;
      times[0].tv_sec = time(0);
      times[1].tv_sec = mtime;
      if( utimes(zFile, times) ){
        return 1;
      }
    }
#endif
  }

  return 0;
}

/*
** Implementation of the "writefile(W,X[,Y[,Z]]])" SQL function.  
** Refer to header comments at the top of this file for details.
*/
static void writefileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zFile;
  mode_t mode = 0;
  int res;
  sqlite3_int64 mtime = -1;

  if( argc<2 || argc>4 ){
    sqlite3_result_error(context, 
        "wrong number of arguments to function writefile()", -1
    );
    return;
  }

  zFile = (const char*)sqlite3_value_text(argv[0]);
  if( zFile==0 ) return;
  if( argc>=3 ){
    mode = (mode_t)sqlite3_value_int(argv[2]);
  }
  if( argc==4 ){
    mtime = sqlite3_value_int64(argv[3]);
  }

  res = writeFile(context, zFile, argv[1], mode, mtime);
  if( res==1 && errno==ENOENT ){
    if( makeDirectory(zFile)==SQLITE_OK ){
      res = writeFile(context, zFile, argv[1], mode, mtime);
    }
  }

  if( argc>2 && res!=0 ){
    if( S_ISLNK(mode) ){
      ctxErrorMsg(context, "failed to create symlink: %s", zFile);
    }else if( S_ISDIR(mode) ){
      ctxErrorMsg(context, "failed to create directory: %s", zFile);
    }else{
      ctxErrorMsg(context, "failed to write file: %s", zFile);
    }
  }
}

/*
** SQL function:   lsmode(MODE)
**
** Given a numberic st_mode from stat(), convert it into a human-readable
** text string in the style of "ls -l".
*/
static void lsModeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int i;
  int iMode = sqlite3_value_int(argv[0]);
  char z[16];
  (void)argc;
  if( S_ISLNK(iMode) ){
    z[0] = 'l';
  }else if( S_ISREG(iMode) ){
    z[0] = '-';
  }else if( S_ISDIR(iMode) ){
    z[0] = 'd';
  }else{
    z[0] = '?';
  }
  for(i=0; i<3; i++){
    int m = (iMode >> ((2-i)*3));
    char *a = &z[1 + i*3];
    a[0] = (m & 0x4) ? 'r' : '-';
    a[1] = (m & 0x2) ? 'w' : '-';
    a[2] = (m & 0x1) ? 'x' : '-';
  }
  z[10] = '\0';
  sqlite3_result_text(context, z, -1, SQLITE_TRANSIENT);
}

#ifndef SQLITE_OMIT_VIRTUALTABLE

/* 
** Cursor type for recursively iterating through a directory structure.
*/
typedef struct fsdir_cursor fsdir_cursor;
typedef struct FsdirLevel FsdirLevel;

struct FsdirLevel {
  DIR *pDir;                 /* From opendir() */
  char *zDir;                /* Name of directory (nul-terminated) */
};

struct fsdir_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */

  int nLvl;                  /* Number of entries in aLvl[] array */
  int mxLvl;                 /* Maximum level */
  int iLvl;                  /* Index of current entry */
  FsdirLevel *aLvl;          /* Hierarchy of directories being traversed */

  const char *zBase;
  int nBase;

  STRUCT_STAT sStat;         /* Current lstat() results */
  char *zPath;               /* Path to current entry */
  sqlite3_int64 iRowid;      /* Current rowid */
};

typedef struct fsdir_tab fsdir_tab;
struct fsdir_tab {
  sqlite3_vtab base;         /* Base class - must be first */
};

/*
** Construct a new fsdir virtual table object.
*/
static int fsdirConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  fsdir_tab *pNew = 0;
  int rc;
  (void)pAux;
  (void)argc;
  (void)argv;
  (void)pzErr;
  rc = sqlite3_declare_vtab(db, "CREATE TABLE x" FSDIR_SCHEMA);
  if( rc==SQLITE_OK ){
    pNew = (fsdir_tab*)sqlite3_malloc64( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    sqlite3_vtab_config(db, SQLITE_VTAB_DIRECTONLY);
  }
  *ppVtab = (sqlite3_vtab*)pNew;
  return rc;
}

/*
** This method is the destructor for fsdir vtab objects.
*/
static int fsdirDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new fsdir_cursor object.
*/
static int fsdirOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  fsdir_cursor *pCur;
  (void)p;
  pCur = sqlite3_malloc64( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->iLvl = -1;
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Reset a cursor back to the state it was in when first returned
** by fsdirOpen().
*/
static void fsdirResetCursor(fsdir_cursor *pCur){
  int i;
  for(i=0; i<=pCur->iLvl; i++){
    FsdirLevel *pLvl = &pCur->aLvl[i];
    if( pLvl->pDir ) closedir(pLvl->pDir);
    sqlite3_free(pLvl->zDir);
  }
  sqlite3_free(pCur->zPath);
  sqlite3_free(pCur->aLvl);
  pCur->aLvl = 0;
  pCur->zPath = 0;
  pCur->zBase = 0;
  pCur->nBase = 0;
  pCur->nLvl = 0;
  pCur->iLvl = -1;
  pCur->iRowid = 1;
}

/*
** Destructor for an fsdir_cursor.
*/
static int fsdirClose(sqlite3_vtab_cursor *cur){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;

  fsdirResetCursor(pCur);
  sqlite3_free(pCur);
  return SQLITE_OK;
}

/*
** Set the error message for the virtual table associated with cursor
** pCur to the results of vprintf(zFmt, ...).
*/
static void fsdirSetErrmsg(fsdir_cursor *pCur, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  pCur->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}


/*
** Advance an fsdir_cursor to its next row of output.
*/
static int fsdirNext(sqlite3_vtab_cursor *cur){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  mode_t m = pCur->sStat.st_mode;

  pCur->iRowid++;
  if( S_ISDIR(m) && pCur->iLvl+3<pCur->mxLvl ){
    /* Descend into this directory */
    int iNew = pCur->iLvl + 1;
    FsdirLevel *pLvl;
    if( iNew>=pCur->nLvl ){
      int nNew = iNew+1;
      sqlite3_int64 nByte = nNew*sizeof(FsdirLevel);
      FsdirLevel *aNew = (FsdirLevel*)sqlite3_realloc64(pCur->aLvl, nByte);
      if( aNew==0 ) return SQLITE_NOMEM;
      memset(&aNew[pCur->nLvl], 0, sizeof(FsdirLevel)*(nNew-pCur->nLvl));
      pCur->aLvl = aNew;
      pCur->nLvl = nNew;
    }
    pCur->iLvl = iNew;
    pLvl = &pCur->aLvl[iNew];
    
    pLvl->zDir = pCur->zPath;
    pCur->zPath = 0;
    pLvl->pDir = opendir(pLvl->zDir);
    if( pLvl->pDir==0 ){
      fsdirSetErrmsg(pCur, "cannot read directory: %s", pLvl->zDir);
      return SQLITE_ERROR;
    }
  }

  while( pCur->iLvl>=0 ){
    FsdirLevel *pLvl = &pCur->aLvl[pCur->iLvl];
    struct dirent *pEntry = readdir(pLvl->pDir);
    if( pEntry ){
      if( pEntry->d_name[0]=='.' ){
       if( pEntry->d_name[1]=='.' && pEntry->d_name[2]=='\0' ) continue;
       if( pEntry->d_name[1]=='\0' ) continue;
      }
      sqlite3_free(pCur->zPath);
      pCur->zPath = sqlite3_mprintf("%s/%s", pLvl->zDir, pEntry->d_name);
      if( pCur->zPath==0 ) return SQLITE_NOMEM;
      if( fileLinkStat(pCur->zPath, &pCur->sStat) ){
        fsdirSetErrmsg(pCur, "cannot stat file: %s", pCur->zPath);
        return SQLITE_ERROR;
      }
      return SQLITE_OK;
    }
    closedir(pLvl->pDir);
    sqlite3_free(pLvl->zDir);
    pLvl->pDir = 0;
    pLvl->zDir = 0;
    pCur->iLvl--;
  }

  /* EOF */
  sqlite3_free(pCur->zPath);
  pCur->zPath = 0;
  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the series_cursor
** is currently pointing.
*/
static int fsdirColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  switch( i ){
    case FSDIR_COLUMN_NAME: {
      sqlite3_result_text(ctx, &pCur->zPath[pCur->nBase], -1, SQLITE_TRANSIENT);
      break;
    }

    case FSDIR_COLUMN_MODE:
      sqlite3_result_int64(ctx, pCur->sStat.st_mode);
      break;

    case FSDIR_COLUMN_MTIME:
      sqlite3_result_int64(ctx, pCur->sStat.st_mtime);
      break;

    case FSDIR_COLUMN_DATA: {
      mode_t m = pCur->sStat.st_mode;
      if( S_ISDIR(m) ){
        sqlite3_result_null(ctx);
#if !defined(_WIN32) && !defined(WIN32)
      }else if( S_ISLNK(m) ){
        char aStatic[64];
        char *aBuf = aStatic;
        sqlite3_int64 nBuf = 64;
        int n;

        while( 1 ){
          n = readlink(pCur->zPath, aBuf, nBuf);
          if( n<nBuf ) break;
          if( aBuf!=aStatic ) sqlite3_free(aBuf);
          nBuf = nBuf*2;
          aBuf = sqlite3_malloc64(nBuf);
          if( aBuf==0 ){
            sqlite3_result_error_nomem(ctx);
            return SQLITE_NOMEM;
          }
        }

        sqlite3_result_text(ctx, aBuf, n, SQLITE_TRANSIENT);
        if( aBuf!=aStatic ) sqlite3_free(aBuf);
#endif
      }else{
        readFileContents(ctx, pCur->zPath);
      }
      break;
    }
    case FSDIR_COLUMN_LEVEL:
      sqlite3_result_int(ctx, pCur->iLvl+2);
      break;
    case FSDIR_COLUMN_PATH:
    default: {
      /* The FSDIR_COLUMN_PATH and FSDIR_COLUMN_DIR are input parameters.
      ** always return their values as NULL */
      break;
    }
  }
  return SQLITE_OK;
}

/*
** Return the rowid for the current row. In this implementation, the
** first row returned is assigned rowid value 1, and each subsequent
** row a value 1 more than that of the previous.
*/
static int fsdirRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  *pRowid = pCur->iRowid;
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int fsdirEof(sqlite3_vtab_cursor *cur){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  return (pCur->zPath==0);
}

/*
** xFilter callback.
**
** idxNum bit      Meaning
**     0x01         PATH=N
**     0x02         DIR=N
**     0x04         LEVEL<N
**     0x08         LEVEL<=N  
*/
static int fsdirFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  const char *zDir = 0;
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  int i;
  (void)idxStr;
  fsdirResetCursor(pCur);

  if( idxNum==0 ){
    fsdirSetErrmsg(pCur, "table function fsdir requires an argument");
    return SQLITE_ERROR;
  }

  assert( (idxNum & 0x01)!=0 && argc>0 );
  zDir = (const char*)sqlite3_value_text(argv[0]);
  if( zDir==0 ){
    fsdirSetErrmsg(pCur, "table function fsdir requires a non-NULL argument");
    return SQLITE_ERROR;
  }
  i = 1;
  if( (idxNum & 0x02)!=0 ){
    assert( argc>i );
    pCur->zBase = (const char*)sqlite3_value_text(argv[i++]);
  }
  if( (idxNum & 0x0c)!=0 ){
    assert( argc>i );
    pCur->mxLvl = sqlite3_value_int(argv[i++]);
    if( idxNum & 0x08 ) pCur->mxLvl++;
    if( pCur->mxLvl<=0 ) pCur->mxLvl = 1000000000;
  }else{
    pCur->mxLvl = 1000000000;
  }
  if( pCur->zBase ){
    pCur->nBase = (int)strlen(pCur->zBase)+1;
    pCur->zPath = sqlite3_mprintf("%s/%s", pCur->zBase, zDir);
  }else{
    pCur->zPath = sqlite3_mprintf("%s", zDir);
  }

  if( pCur->zPath==0 ){
    return SQLITE_NOMEM;
  }
  if( fileLinkStat(pCur->zPath, &pCur->sStat) ){
    fsdirSetErrmsg(pCur, "cannot stat file: %s", pCur->zPath);
    return SQLITE_ERROR;
  }

  return SQLITE_OK;
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the generate_series virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** In this implementation idxNum is used to represent the
** query plan.  idxStr is unused.
**
** The query plan is represented by bits in idxNum:
**
**  0x01  The path value is supplied by argv[0]
**  0x02  dir is in argv[1]
**  0x04  maxdepth is in argv[1] or [2]
*/
static int fsdirBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;                 /* Loop over constraints */
  int idxPath = -1;      /* Index in pIdxInfo->aConstraint of PATH= */
  int idxDir = -1;       /* Index in pIdxInfo->aConstraint of DIR= */
  int idxLevel = -1;     /* Index in pIdxInfo->aConstraint of LEVEL< or <= */
  int idxLevelEQ = 0;    /* 0x08 for LEVEL<= or LEVEL=.  0x04 for LEVEL< */
  int omitLevel = 0;     /* omit the LEVEL constraint */
  int seenPath = 0;      /* True if an unusable PATH= constraint is seen */
  int seenDir = 0;       /* True if an unusable DIR= constraint is seen */
  const struct sqlite3_index_constraint *pConstraint;

  (void)tab;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      switch( pConstraint->iColumn ){
        case FSDIR_COLUMN_PATH: {
          if( pConstraint->usable ){
            idxPath = i;
            seenPath = 0;
          }else if( idxPath<0 ){
            seenPath = 1;
          }
          break;
        }
        case FSDIR_COLUMN_DIR: {
          if( pConstraint->usable ){
            idxDir = i;
            seenDir = 0;
          }else if( idxDir<0 ){
            seenDir = 1;
          }
          break;
        }
        case FSDIR_COLUMN_LEVEL: {
          if( pConstraint->usable && idxLevel<0 ){
            idxLevel = i;
            idxLevelEQ = 0x08;
            omitLevel = 0;
          }
          break;
        }
      }
    }else
    if( pConstraint->iColumn==FSDIR_COLUMN_LEVEL
     && pConstraint->usable
     && idxLevel<0
    ){
      if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE ){
        idxLevel = i;
        idxLevelEQ = 0x08;
        omitLevel = 1;
      }else if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ){
        idxLevel = i;
        idxLevelEQ = 0x04;
        omitLevel = 1;
      }
    } 
  }
  if( seenPath || seenDir ){
    /* If input parameters are unusable, disallow this plan */
    return SQLITE_CONSTRAINT;
  }

  if( idxPath<0 ){
    pIdxInfo->idxNum = 0;
    /* The pIdxInfo->estimatedCost should have been initialized to a huge
    ** number.  Leave it unchanged. */
    pIdxInfo->estimatedRows = 0x7fffffff;
  }else{
    pIdxInfo->aConstraintUsage[idxPath].omit = 1;
    pIdxInfo->aConstraintUsage[idxPath].argvIndex = 1;
    pIdxInfo->idxNum = 0x01;
    pIdxInfo->estimatedCost = 1.0e9;
    i = 2;
    if( idxDir>=0 ){
      pIdxInfo->aConstraintUsage[idxDir].omit = 1;
      pIdxInfo->aConstraintUsage[idxDir].argvIndex = i++;
      pIdxInfo->idxNum |= 0x02;
      pIdxInfo->estimatedCost /= 1.0e4;
    }
    if( idxLevel>=0 ){
      pIdxInfo->aConstraintUsage[idxLevel].omit = omitLevel;
      pIdxInfo->aConstraintUsage[idxLevel].argvIndex = i++;
      pIdxInfo->idxNum |= idxLevelEQ;
      pIdxInfo->estimatedCost /= 1.0e4;
    }
  }

  return SQLITE_OK;
}

/*
** Register the "fsdir" virtual table.
*/
static int fsdirRegister(sqlite3 *db){
  static sqlite3_module fsdirModule = {
    0,                         /* iVersion */
    0,                         /* xCreate */
    fsdirConnect,              /* xConnect */
    fsdirBestIndex,            /* xBestIndex */
    fsdirDisconnect,           /* xDisconnect */
    0,                         /* xDestroy */
    fsdirOpen,                 /* xOpen - open a cursor */
    fsdirClose,                /* xClose - close a cursor */
    fsdirFilter,               /* xFilter - configure scan constraints */
    fsdirNext,                 /* xNext - advance a cursor */
    fsdirEof,                  /* xEof - check for end of scan */
    fsdirColumn,               /* xColumn - read data */
    fsdirRowid,                /* xRowid - read data */
    0,                         /* xUpdate */
    0,                         /* xBegin */
    0,                         /* xSync */
    0,                         /* xCommit */
    0,                         /* xRollback */
    0,                         /* xFindMethod */
    0,                         /* xRename */
    0,                         /* xSavepoint */
    0,                         /* xRelease */
    0,                         /* xRollbackTo */
    0,                         /* xShadowName */
    0                          /* xIntegrity */
  };

  int rc = sqlite3_create_module(db, "fsdir", &fsdirModule, 0);
  return rc;
}
#else         /* SQLITE_OMIT_VIRTUALTABLE */
# define fsdirRegister(x) SQLITE_OK
#endif

/*
** This version of realpath() works on any system.  The string
** returned is held in memory allocated using sqlite3_malloc64().
** The caller is responsible for calling sqlite3_free().
*/
static char *portable_realpath(const char *zPath){
#if !defined(_WIN32)       /* BEGIN unix */

  char *zOut = 0;          /* Result */
  char *z;                 /* Temporary buffer */
#if defined(PATH_MAX)
  char zBuf[PATH_MAX+1];   /* Space for the temporary buffer */
#endif

  if( zPath==0 ) return 0;
#if defined(PATH_MAX)
  z = realpath(zPath, zBuf);
  if( z ){
    zOut = sqlite3_mprintf("%s", zBuf);
  }
#endif /* defined(PATH_MAX) */
  if( zOut==0 ){
    /* Try POSIX.1-2008 malloc behavior */
    z = realpath(zPath, NULL);
    if( z ){
      zOut = sqlite3_mprintf("%s", z);
      free(z);
    }
  }
  return zOut;

#else /* End UNIX, Begin WINDOWS */

  wchar_t *zPath16;        /* UTF16 translation of zPath */
  char *zOut = 0;          /* Result */
  wchar_t *z = 0;          /* Temporary buffer */

  if( zPath==0 ) return 0;

  zPath16 = sqlite3_win32_utf8_to_unicode(zPath);
  if( zPath16==0 ) return 0;
  z = _wfullpath(NULL, zPath16, 0);
  sqlite3_free(zPath16);
  if( z ){
    zOut = sqlite3_win32_unicode_to_utf8(z);
    free(z);
  }
  return zOut;

#endif /* End WINDOWS, Begin common code */
}

/*
** SQL function:   realpath(X)
**
** Try to convert file or pathname X into its real, absolute pathname.
** Return NULL if unable.
**
** The file or directory X is not required to exist.  The answer is formed
** by calling system realpath() on the prefix of X that does exist and
** appending the tail of X that does not (yet) exist.
*/
static void realpathFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zPath;    /* Original input path */
  char *zCopy;          /* An editable copy of zPath */
  char *zOut;           /* The result */
  char cSep = 0;        /* Separator turned into \000 */
  size_t len;           /* Prefix length before cSep */
#ifdef _WIN32
  const int isWin = 1;
#else
  const int isWin = 0;
#endif

  (void)argc;
  zPath = (const char*)sqlite3_value_text(argv[0]);
  if( zPath==0 ) return;
  if( zPath[0]==0 ) zPath = ".";
  zCopy = sqlite3_mprintf("%s",zPath);
  len = strlen(zCopy);
  while( len>1 && (zCopy[len-1]=='/' || (isWin && zCopy[len-1]=='\\')) ){
    len--;
  }
  zCopy[len] = 0;
  while( 1 /*exit-by-break*/ ){
    zOut = portable_realpath(zCopy);
    zCopy[len] = cSep;
    if( zOut ){
      if( cSep ){
        zOut = sqlite3_mprintf("%z%s",zOut,&zCopy[len]);
      }
      break;
    }else{
      size_t i = len-1;
      while( i>0 ){
        if( zCopy[i]=='/' || (isWin && zCopy[i]=='\\') ) break;
        i--;
      }
      if( i<=0 ){
        if( zCopy[0]=='/' ){
          zOut = zCopy;
          zCopy = 0;
        }else if( (zOut = portable_realpath("."))!=0 ){
          zOut = sqlite3_mprintf("%z/%s", zOut, zCopy);
        }          
        break;
      }
      cSep = zCopy[i];
      zCopy[i] = 0;
      len = i;
    }
  }
  sqlite3_free(zCopy);
  if( zOut ){
    /* Simplify any "/./" or "/../" that might have snuck into the
    ** pathname due to appending of zCopy.  We only have to consider
    ** unix "/" separators, because the _wfilepath() system call on
    ** Windows will have already done this simplification for us. */
    size_t i, j, n;
    n = strlen(zOut);
    for(i=j=0; i<n; i++){
      if( zOut[i]=='/' ){
        if( zOut[i+1]=='/' ) continue;
        if( zOut[i+1]=='.' && i+2<n && zOut[i+2]=='/' ){
          i += 1;
          continue;
        }
        if( zOut[i+1]=='.' && i+3<n && zOut[i+2]=='.' && zOut[i+3]=='/' ){
          while( j>0 && zOut[j-1]!='/' ){ j--; }
          if( j>0 ){ j--; }
          i += 2;
          continue;
        }
      }
      zOut[j++] = zOut[i];
    }
    zOut[j] = 0;

    /* Return the result */
    sqlite3_result_text(context, zOut, -1, sqlite3_free);
  }
}


#ifdef _WIN32

#endif
int sqlite3_fileio_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "readfile", 1, 
                               SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                               readfileFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "writefile", -1,
                                 SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                                 writefileFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "lsmode", 1, SQLITE_UTF8, 0,
                                 lsModeFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = fsdirRegister(db);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "realpath", 1,
                                 SQLITE_UTF8, 0,
                                 realpathFunc, 0, 0);
  }
  return rc;
}

/************************* End ext/misc/fileio.c ********************/
/************************* Begin ext/misc/completion.c ******************/
/*
** 2017-07-10
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements an eponymous virtual table that returns suggested
** completions for a partial SQL input.
**
** Suggested usage:
**
**     SELECT DISTINCT candidate COLLATE nocase
**       FROM completion($prefix,$wholeline)
**      ORDER BY 1;
**
** The two query parameters are optional.  $prefix is the text of the
** current word being typed and that is to be completed.  $wholeline is
** the complete input line, used for context.
**
** The raw completion() table might return the same candidate multiple
** times, for example if the same column name is used to two or more
** tables.  And the candidates are returned in an arbitrary order.  Hence,
** the DISTINCT and ORDER BY are recommended.
**
** This virtual table operates at the speed of human typing, and so there
** is no attempt to make it fast.  Even a slow implementation will be much
** faster than any human can type.
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

#ifndef IsAlnum
#define IsAlnum(X)  isalnum((unsigned char)X)
#endif


/* completion_vtab is a subclass of sqlite3_vtab which will
** serve as the underlying representation of a completion virtual table
*/
typedef struct completion_vtab completion_vtab;
struct completion_vtab {
  sqlite3_vtab base;  /* Base class - must be first */
  sqlite3 *db;        /* Database connection for this completion vtab */
};

/* completion_cursor is a subclass of sqlite3_vtab_cursor which will
** serve as the underlying representation of a cursor that scans
** over rows of the result
*/
typedef struct completion_cursor completion_cursor;
struct completion_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  sqlite3 *db;               /* Database connection for this cursor */
  int nPrefix, nLine;        /* Number of bytes in zPrefix and zLine */
  char *zPrefix;             /* The prefix for the word we want to complete */
  char *zLine;               /* The whole that we want to complete */
  const char *zCurrentRow;   /* Current output row */
  int szRow;                 /* Length of the zCurrentRow string */
  sqlite3_stmt *pStmt;       /* Current statement */
  sqlite3_int64 iRowid;      /* The rowid */
  int ePhase;                /* Current phase */
  int j;                     /* inter-phase counter */
};

/* Values for ePhase:
*/
#define COMPLETION_FIRST_PHASE   1
#define COMPLETION_KEYWORDS      1
#define COMPLETION_PRAGMAS       2
#define COMPLETION_FUNCTIONS     3
#define COMPLETION_COLLATIONS    4
#define COMPLETION_INDEXES       5
#define COMPLETION_TRIGGERS      6
#define COMPLETION_DATABASES     7
#define COMPLETION_TABLES        8    /* Also VIEWs and TRIGGERs */
#define COMPLETION_COLUMNS       9
#define COMPLETION_MODULES       10
#define COMPLETION_EOF           11

/*
** The completionConnect() method is invoked to create a new
** completion_vtab that describes the completion virtual table.
**
** Think of this routine as the constructor for completion_vtab objects.
**
** All this routine needs to do is:
**
**    (1) Allocate the completion_vtab object and initialize all fields.
**
**    (2) Tell SQLite (via the sqlite3_declare_vtab() interface) what the
**        result set of queries against completion will look like.
*/
static int completionConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  completion_vtab *pNew;
  int rc;

  (void)(pAux);    /* Unused parameter */
  (void)(argc);    /* Unused parameter */
  (void)(argv);    /* Unused parameter */
  (void)(pzErr);   /* Unused parameter */

/* Column numbers */
#define COMPLETION_COLUMN_CANDIDATE 0  /* Suggested completion of the input */
#define COMPLETION_COLUMN_PREFIX    1  /* Prefix of the word to be completed */
#define COMPLETION_COLUMN_WHOLELINE 2  /* Entire line seen so far */
#define COMPLETION_COLUMN_PHASE     3  /* ePhase - used for debugging only */

  sqlite3_vtab_config(db, SQLITE_VTAB_INNOCUOUS);
  rc = sqlite3_declare_vtab(db,
      "CREATE TABLE x("
      "  candidate TEXT,"
      "  prefix TEXT HIDDEN,"
      "  wholeline TEXT HIDDEN,"
      "  phase INT HIDDEN"        /* Used for debugging only */
      ")");
  if( rc==SQLITE_OK ){
    pNew = sqlite3_malloc64( sizeof(*pNew) );
    *ppVtab = (sqlite3_vtab*)pNew;
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    pNew->db = db;
  }
  return rc;
}

/*
** This method is the destructor for completion_cursor objects.
*/
static int completionDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new completion_cursor object.
*/
static int completionOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  completion_cursor *pCur;
  pCur = sqlite3_malloc64( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->db = ((completion_vtab*)p)->db;
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Reset the completion_cursor.
*/
static void completionCursorReset(completion_cursor *pCur){
  sqlite3_free(pCur->zPrefix);   pCur->zPrefix = 0;  pCur->nPrefix = 0;
  sqlite3_free(pCur->zLine);     pCur->zLine = 0;    pCur->nLine = 0;
  sqlite3_finalize(pCur->pStmt); pCur->pStmt = 0;
  pCur->j = 0;
}

/*
** Destructor for a completion_cursor.
*/
static int completionClose(sqlite3_vtab_cursor *cur){
  completionCursorReset((completion_cursor*)cur);
  sqlite3_free(cur);
  return SQLITE_OK;
}

/*
** Advance a completion_cursor to its next row of output.
**
** The ->ePhase, ->j, and ->pStmt fields of the completion_cursor object
** record the current state of the scan.  This routine sets ->zCurrentRow
** to the current row of output and then returns.  If no more rows remain,
** then ->ePhase is set to COMPLETION_EOF which will signal the virtual
** table that has reached the end of its scan.
**
** The current implementation just lists potential identifiers and
** keywords and filters them by zPrefix.  Future enhancements should
** take zLine into account to try to restrict the set of identifiers and
** keywords based on what would be legal at the current point of input.
*/
static int completionNext(sqlite3_vtab_cursor *cur){
  completion_cursor *pCur = (completion_cursor*)cur;
  int eNextPhase = 0;  /* Next phase to try if current phase reaches end */
  int iCol = -1;       /* If >=0, step pCur->pStmt and use the i-th column */
  int rc;
  pCur->iRowid++;
  while( pCur->ePhase!=COMPLETION_EOF ){
    switch( pCur->ePhase ){
      case COMPLETION_KEYWORDS: {
        if( pCur->j >= sqlite3_keyword_count() ){
          pCur->zCurrentRow = 0;
          pCur->ePhase = COMPLETION_DATABASES;
        }else{
          sqlite3_keyword_name(pCur->j++, &pCur->zCurrentRow, &pCur->szRow);
        }
        iCol = -1;
        break;
      }
      case COMPLETION_DATABASES: {
        if( pCur->pStmt==0 ){
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1,
                             &pCur->pStmt, 0);
        }
        iCol = 1;
        eNextPhase = COMPLETION_TABLES;
        break;
      }
      case COMPLETION_TABLES: {
        if( pCur->pStmt==0 ){
          sqlite3_stmt *pS2;
          sqlite3_str* pStr = sqlite3_str_new(pCur->db);
          char *zSql = 0;
          const char *zSep = "";
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1, &pS2, 0);
          while( sqlite3_step(pS2)==SQLITE_ROW ){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            sqlite3_str_appendf(pStr,
               "%s"
               "SELECT name FROM \"%w\".sqlite_schema",
               zSep, zDb
            );
            zSep = " UNION ";
          }
          rc = sqlite3_finalize(pS2);
          zSql = sqlite3_str_finish(pStr);
          if( zSql==0 ) return SQLITE_NOMEM;
          if( rc==SQLITE_OK ){
            sqlite3_prepare_v2(pCur->db, zSql, -1, &pCur->pStmt, 0);
          }
          sqlite3_free(zSql);
          if( rc ) return rc;
        }
        iCol = 0;
        eNextPhase = COMPLETION_COLUMNS;
        break;
      }
      case COMPLETION_COLUMNS: {
        if( pCur->pStmt==0 ){
          sqlite3_stmt *pS2;
          sqlite3_str *pStr = sqlite3_str_new(pCur->db);
          char *zSql = 0;
          const char *zSep = "";
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1, &pS2, 0);
          while( sqlite3_step(pS2)==SQLITE_ROW ){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            sqlite3_str_appendf(pStr,
               "%s"
               "SELECT pti.name FROM \"%w\".sqlite_schema AS sm"
                       " JOIN pragma_table_xinfo(sm.name,%Q) AS pti"
               " WHERE sm.type='table'",
               zSep, zDb, zDb
            );
            zSep = " UNION ";
          }
          rc = sqlite3_finalize(pS2);
          zSql = sqlite3_str_finish(pStr);
          if( zSql==0 ) return SQLITE_NOMEM;
          if( rc==SQLITE_OK ){
            sqlite3_prepare_v2(pCur->db, zSql, -1, &pCur->pStmt, 0);
          }
          sqlite3_free(zSql);
          if( rc ) return rc;
        }
        iCol = 0;
        eNextPhase = COMPLETION_EOF;
        break;
      }
    }
    if( iCol<0 ){
      /* This case is when the phase presets zCurrentRow */
      if( pCur->zCurrentRow==0 ) continue;
    }else{
      if( sqlite3_step(pCur->pStmt)==SQLITE_ROW ){
        /* Extract the next row of content */
        pCur->zCurrentRow = (const char*)sqlite3_column_text(pCur->pStmt, iCol);
        pCur->szRow = sqlite3_column_bytes(pCur->pStmt, iCol);
      }else{
        /* When all rows are finished, advance to the next phase */
        rc = sqlite3_finalize(pCur->pStmt);
        pCur->pStmt = 0;
        pCur->ePhase = eNextPhase;
        if( rc ) return rc;
        continue;
      }
    }
    if( pCur->nPrefix==0 ) break;
    if( pCur->nPrefix<=pCur->szRow
     && sqlite3_strnicmp(pCur->zPrefix, pCur->zCurrentRow, pCur->nPrefix)==0
    ){
      break;
    }
  }

  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the completion_cursor
** is currently pointing.
*/
static int completionColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  completion_cursor *pCur = (completion_cursor*)cur;
  switch( i ){
    case COMPLETION_COLUMN_CANDIDATE: {
      sqlite3_result_text(ctx, pCur->zCurrentRow, pCur->szRow,SQLITE_TRANSIENT);
      break;
    }
    case COMPLETION_COLUMN_PREFIX: {
      sqlite3_result_text(ctx, pCur->zPrefix, -1, SQLITE_TRANSIENT);
      break;
    }
    case COMPLETION_COLUMN_WHOLELINE: {
      sqlite3_result_text(ctx, pCur->zLine, -1, SQLITE_TRANSIENT);
      break;
    }
    case COMPLETION_COLUMN_PHASE: {
      sqlite3_result_int(ctx, pCur->ePhase);
      break;
    }
  }
  return SQLITE_OK;
}

/*
** Return the rowid for the current row.  In this implementation, the
** rowid is the same as the output value.
*/
static int completionRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  completion_cursor *pCur = (completion_cursor*)cur;
  *pRowid = pCur->iRowid;
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int completionEof(sqlite3_vtab_cursor *cur){
  completion_cursor *pCur = (completion_cursor*)cur;
  return pCur->ePhase >= COMPLETION_EOF;
}

/*
** This method is called to "rewind" the completion_cursor object back
** to the first row of output.  This method is always called at least
** once prior to any call to completionColumn() or completionRowid() or 
** completionEof().
*/
static int completionFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  completion_cursor *pCur = (completion_cursor *)pVtabCursor;
  int iArg = 0;
  (void)(idxStr);   /* Unused parameter */
  (void)(argc);     /* Unused parameter */
  completionCursorReset(pCur);
  if( idxNum & 1 ){
    pCur->nPrefix = sqlite3_value_bytes(argv[iArg]);
    if( pCur->nPrefix>0 ){
      pCur->zPrefix = sqlite3_mprintf("%s", sqlite3_value_text(argv[iArg]));
      if( pCur->zPrefix==0 ) return SQLITE_NOMEM;
      pCur->nPrefix = (int)strlen(pCur->zPrefix);
    }
    iArg = 1;
  }
  if( idxNum & 2 ){
    pCur->nLine = sqlite3_value_bytes(argv[iArg]);
    if( pCur->nLine>0 ){
      pCur->zLine = sqlite3_mprintf("%s", sqlite3_value_text(argv[iArg]));
      if( pCur->zLine==0 ) return SQLITE_NOMEM;
      pCur->nLine = (int)strlen(pCur->zLine);
    }
  }
  if( pCur->zLine!=0 && pCur->zPrefix==0 ){
    int i = pCur->nLine;
    while( i>0 && (IsAlnum(pCur->zLine[i-1]) || pCur->zLine[i-1]=='_') ){
      i--;
    }
    pCur->nPrefix = pCur->nLine - i;
    if( pCur->nPrefix>0 ){
      pCur->zPrefix = sqlite3_mprintf("%.*s", pCur->nPrefix, pCur->zLine + i);
      if( pCur->zPrefix==0 ) return SQLITE_NOMEM;
      pCur->nPrefix = (int)strlen(pCur->zPrefix);
    }
  }
  pCur->iRowid = 0;
  pCur->ePhase = COMPLETION_FIRST_PHASE;
  return completionNext(pVtabCursor);
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the completion virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** There are two hidden parameters that act as arguments to the table-valued
** function:  "prefix" and "wholeline".  Bit 0 of idxNum is set if "prefix"
** is available and bit 1 is set if "wholeline" is available.
*/
static int completionBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;                 /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
  int prefixIdx = -1;    /* Index of the start= constraint, or -1 if none */
  int wholelineIdx = -1; /* Index of the stop= constraint, or -1 if none */
  int nArg = 0;          /* Number of arguments that completeFilter() expects */
  const struct sqlite3_index_constraint *pConstraint;

  (void)(tab);    /* Unused parameter */
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case COMPLETION_COLUMN_PREFIX:
        prefixIdx = i;
        idxNum |= 1;
        break;
      case COMPLETION_COLUMN_WHOLELINE:
        wholelineIdx = i;
        idxNum |= 2;
        break;
    }
  }
  if( prefixIdx>=0 ){
    pIdxInfo->aConstraintUsage[prefixIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[prefixIdx].omit = 1;
  }
  if( wholelineIdx>=0 ){
    pIdxInfo->aConstraintUsage[wholelineIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[wholelineIdx].omit = 1;
  }
  pIdxInfo->idxNum = idxNum;
  pIdxInfo->estimatedCost = (double)5000 - 1000*nArg;
  pIdxInfo->estimatedRows = 500 - 100*nArg;
  return SQLITE_OK;
}

/*
** This following structure defines all the methods for the 
** completion virtual table.
*/
static const sqlite3_module completionModule = {
  0,                         /* iVersion */
  0,                         /* xCreate */
  completionConnect,         /* xConnect */
  completionBestIndex,       /* xBestIndex */
  completionDisconnect,      /* xDisconnect */
  0,                         /* xDestroy */
  completionOpen,            /* xOpen - open a cursor */
  completionClose,           /* xClose - close a cursor */
  completionFilter,          /* xFilter - configure scan constraints */
  completionNext,            /* xNext - advance a cursor */
  completionEof,             /* xEof - check for end of scan */
  completionColumn,          /* xColumn - read data */
  completionRowid,           /* xRowid - read data */
  0,                         /* xUpdate */
  0,                         /* xBegin */
  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
  0,                         /* xSavepoint */
  0,                         /* xRelease */
  0,                         /* xRollbackTo */
  0,                         /* xShadowName */
  0                          /* xIntegrity */
};

#endif /* SQLITE_OMIT_VIRTUALTABLE */

int sqlite3CompletionVtabInit(sqlite3 *db){
  int rc = SQLITE_OK;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3_create_module(db, "completion", &completionModule, 0);
#endif
  return rc;
}

#ifdef _WIN32

#endif
int sqlite3_completion_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)(pzErrMsg);  /* Unused parameter */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3CompletionVtabInit(db);
#endif
  return rc;
}
#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)(pzErrMsg);  /* Unused parameter */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3CompletionVtabInit(db);
#endif
  return rc;
}
#endif

/************************* End ext/misc/completion.c ********************/
/************************* Begin ext/misc/appendvfs.c ******************/
/*
** 2017-10-20
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements a VFS shim that allows an SQLite database to be
** appended onto the end of some other file, such as an executable.
**
** A special record must appear at the end of the file that identifies the
** file as an appended database and provides the offset to the first page
** of the exposed content. (Or, it is the length of the content prefix.)
** For best performance page 1 should be located at a disk page boundary,
** though that is not required.
**
** When opening a database using this VFS, the connection might treat
** the file as an ordinary SQLite database, or it might treat it as a
** database appended onto some other file.  The decision is made by
** applying the following rules in order:
**
**  (1)  An empty file is an ordinary database.
**
**  (2)  If the file ends with the appendvfs trailer string
**       "Start-Of-SQLite3-NNNNNNNN" that file is an appended database.
**
**  (3)  If the file begins with the standard SQLite prefix string
**       "SQLite format 3", that file is an ordinary database.
**
**  (4)  If none of the above apply and the SQLITE_OPEN_CREATE flag is
**       set, then a new database is appended to the already existing file.
**
**  (5)  Otherwise, SQLITE_CANTOPEN is returned.
**
** To avoid unnecessary complications with the PENDING_BYTE, the size of
** the file containing the database is limited to 1GiB. (1073741824 bytes)
** This VFS will not read or write past the 1GiB mark.  This restriction
** might be lifted in future versions.  For now, if you need a larger
** database, then keep it in a separate file.
**
** If the file being opened is a plain database (not an appended one), then
** this shim is a pass-through into the default underlying VFS. (rule 3)
**/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <string.h>
#include <assert.h>

/* The append mark at the end of the database is:
**
**     Start-Of-SQLite3-NNNNNNNN
**     123456789 123456789 12345
**
** The NNNNNNNN represents a 64-bit big-endian unsigned integer which is
** the offset to page 1, and also the length of the prefix content.
*/
#define APND_MARK_PREFIX     "Start-Of-SQLite3-"
#define APND_MARK_PREFIX_SZ  17
#define APND_MARK_FOS_SZ      8
#define APND_MARK_SIZE       (APND_MARK_PREFIX_SZ+APND_MARK_FOS_SZ)

/*
** Maximum size of the combined prefix + database + append-mark.  This
** must be less than 0x40000000 to avoid locking issues on Windows.
*/
#define APND_MAX_SIZE  (0x40000000)

/*
** Try to align the database to an even multiple of APND_ROUNDUP bytes.
*/
#ifndef APND_ROUNDUP
#define APND_ROUNDUP 4096
#endif
#define APND_ALIGN_MASK         ((sqlite3_int64)(APND_ROUNDUP-1))
#define APND_START_ROUNDUP(fsz) (((fsz)+APND_ALIGN_MASK) & ~APND_ALIGN_MASK)

/*
** Forward declaration of objects used by this utility
*/
typedef struct sqlite3_vfs ApndVfs;
typedef struct ApndFile ApndFile;

/* Access to a lower-level VFS that (might) implement dynamic loading,
** access to randomness, etc.
*/
#define ORIGVFS(p)  ((sqlite3_vfs*)((p)->pAppData))
#define ORIGFILE(p) ((sqlite3_file*)(((ApndFile*)(p))+1))

/* An open appendvfs file
**
** An instance of this structure describes the appended database file.
** A separate sqlite3_file object is always appended. The appended
** sqlite3_file object (which can be accessed using ORIGFILE()) describes
** the entire file, including the prefix, the database, and the
** append-mark.
**
** The structure of an AppendVFS database is like this:
**
**   +-------------+---------+----------+-------------+
**   | prefix-file | padding | database | append-mark |
**   +-------------+---------+----------+-------------+
**                           ^          ^
**                           |          |
**                         iPgOne      iMark
**
**
** "prefix file" -  file onto which the database has been appended.
** "padding"     -  zero or more bytes inserted so that "database"
**                  starts on an APND_ROUNDUP boundary
** "database"    -  The SQLite database file
** "append-mark" -  The 25-byte "Start-Of-SQLite3-NNNNNNNN" that indicates
**                  the offset from the start of prefix-file to the start
**                  of "database".
**
** The size of the database is iMark - iPgOne.
**
** The NNNNNNNN in the "Start-Of-SQLite3-NNNNNNNN" suffix is the value
** of iPgOne stored as a big-ending 64-bit integer.
**
** iMark will be the size of the underlying file minus 25 (APND_MARKSIZE).
** Or, iMark is -1 to indicate that it has not yet been written.
*/
struct ApndFile {
  sqlite3_file base;        /* Subclass.  MUST BE FIRST! */
  sqlite3_int64 iPgOne;     /* Offset to the start of the database */
  sqlite3_int64 iMark;      /* Offset of the append mark.  -1 if unwritten */
  /* Always followed by another sqlite3_file that describes the whole file */
};

/*
** Methods for ApndFile
*/
static int apndClose(sqlite3_file*);
static int apndRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int apndWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
static int apndTruncate(sqlite3_file*, sqlite3_int64 size);
static int apndSync(sqlite3_file*, int flags);
static int apndFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int apndLock(sqlite3_file*, int);
static int apndUnlock(sqlite3_file*, int);
static int apndCheckReservedLock(sqlite3_file*, int *pResOut);
static int apndFileControl(sqlite3_file*, int op, void *pArg);
static int apndSectorSize(sqlite3_file*);
static int apndDeviceCharacteristics(sqlite3_file*);
static int apndShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
static int apndShmLock(sqlite3_file*, int offset, int n, int flags);
static void apndShmBarrier(sqlite3_file*);
static int apndShmUnmap(sqlite3_file*, int deleteFlag);
static int apndFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
static int apndUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);

/*
** Methods for ApndVfs
*/
static int apndOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
static int apndDelete(sqlite3_vfs*, const char *zName, int syncDir);
static int apndAccess(sqlite3_vfs*, const char *zName, int flags, int *);
static int apndFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
static void *apndDlOpen(sqlite3_vfs*, const char *zFilename);
static void apndDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
static void apndDlClose(sqlite3_vfs*, void*);
static int apndRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int apndSleep(sqlite3_vfs*, int microseconds);
static int apndCurrentTime(sqlite3_vfs*, double*);
static int apndGetLastError(sqlite3_vfs*, int, char *);
static int apndCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
static int apndSetSystemCall(sqlite3_vfs*, const char*,sqlite3_syscall_ptr);
static sqlite3_syscall_ptr apndGetSystemCall(sqlite3_vfs*, const char *z);
static const char *apndNextSystemCall(sqlite3_vfs*, const char *zName);

static sqlite3_vfs apnd_vfs = {
  3,                            /* iVersion (set when registered) */
  0,                            /* szOsFile (set when registered) */
  1024,                         /* mxPathname */
  0,                            /* pNext */
  "apndvfs",                    /* zName */
  0,                            /* pAppData (set when registered) */ 
  apndOpen,                     /* xOpen */
  apndDelete,                   /* xDelete */
  apndAccess,                   /* xAccess */
  apndFullPathname,             /* xFullPathname */
  apndDlOpen,                   /* xDlOpen */
  apndDlError,                  /* xDlError */
  apndDlSym,                    /* xDlSym */
  apndDlClose,                  /* xDlClose */
  apndRandomness,               /* xRandomness */
  apndSleep,                    /* xSleep */
  apndCurrentTime,              /* xCurrentTime */
  apndGetLastError,             /* xGetLastError */
  apndCurrentTimeInt64,         /* xCurrentTimeInt64 */
  apndSetSystemCall,            /* xSetSystemCall */
  apndGetSystemCall,            /* xGetSystemCall */
  apndNextSystemCall            /* xNextSystemCall */
};

static const sqlite3_io_methods apnd_io_methods = {
  3,                              /* iVersion */
  apndClose,                      /* xClose */
  apndRead,                       /* xRead */
  apndWrite,                      /* xWrite */
  apndTruncate,                   /* xTruncate */
  apndSync,                       /* xSync */
  apndFileSize,                   /* xFileSize */
  apndLock,                       /* xLock */
  apndUnlock,                     /* xUnlock */
  apndCheckReservedLock,          /* xCheckReservedLock */
  apndFileControl,                /* xFileControl */
  apndSectorSize,                 /* xSectorSize */
  apndDeviceCharacteristics,      /* xDeviceCharacteristics */
  apndShmMap,                     /* xShmMap */
  apndShmLock,                    /* xShmLock */
  apndShmBarrier,                 /* xShmBarrier */
  apndShmUnmap,                   /* xShmUnmap */
  apndFetch,                      /* xFetch */
  apndUnfetch                     /* xUnfetch */
};

/*
** Close an apnd-file.
*/
static int apndClose(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xClose(pFile);
}

/*
** Read data from an apnd-file.
*/
static int apndRead(
  sqlite3_file *pFile, 
  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  ApndFile *paf = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xRead(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
}

/*
** Add the append-mark onto what should become the end of the file.
*  If and only if this succeeds, internal ApndFile.iMark is updated.
*  Parameter iWriteEnd is the appendvfs-relative offset of the new mark.
*/
static int apndWriteMark(
  ApndFile *paf,
  sqlite3_file *pFile,
  sqlite_int64 iWriteEnd
){
  sqlite_int64 iPgOne = paf->iPgOne;
  unsigned char a[APND_MARK_SIZE];
  int i = APND_MARK_FOS_SZ;
  int rc;
  assert(pFile == ORIGFILE(paf));
  memcpy(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ);
  while( --i >= 0 ){
    a[APND_MARK_PREFIX_SZ+i] = (unsigned char)(iPgOne & 0xff);
    iPgOne >>= 8;
  }
  iWriteEnd += paf->iPgOne;
  if( SQLITE_OK==(rc = pFile->pMethods->xWrite
                  (pFile, a, APND_MARK_SIZE, iWriteEnd)) ){
    paf->iMark = iWriteEnd;
  }
  return rc;
}

/*
** Write data to an apnd-file.
*/
static int apndWrite(
  sqlite3_file *pFile,
  const void *zBuf,
  int iAmt,
  sqlite_int64 iOfst
){
  ApndFile *paf = (ApndFile *)pFile;
  sqlite_int64 iWriteEnd = iOfst + iAmt;
  if( iWriteEnd>=APND_MAX_SIZE ) return SQLITE_FULL;
  pFile = ORIGFILE(pFile);
  /* If append-mark is absent or will be overwritten, write it. */
  if( paf->iMark < 0 || paf->iPgOne + iWriteEnd > paf->iMark ){
    int rc = apndWriteMark(paf, pFile, iWriteEnd);
    if( SQLITE_OK!=rc ) return rc;
  }
  return pFile->pMethods->xWrite(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
}

/*
** Truncate an apnd-file.
*/
static int apndTruncate(sqlite3_file *pFile, sqlite_int64 size){
  ApndFile *paf = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
  /* The append mark goes out first so truncate failure does not lose it. */
  if( SQLITE_OK!=apndWriteMark(paf, pFile, size) ) return SQLITE_IOERR;
  /* Truncate underlying file just past append mark */
  return pFile->pMethods->xTruncate(pFile, paf->iMark+APND_MARK_SIZE);
}

/*
** Sync an apnd-file.
*/
static int apndSync(sqlite3_file *pFile, int flags){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xSync(pFile, flags);
}

/*
** Return the current file-size of an apnd-file.
** If the append mark is not yet there, the file-size is 0.
*/
static int apndFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  ApndFile *paf = (ApndFile *)pFile;
  *pSize = ( paf->iMark >= 0 )? (paf->iMark - paf->iPgOne) : 0;
  return SQLITE_OK;
}

/*
** Lock an apnd-file.
*/
static int apndLock(sqlite3_file *pFile, int eLock){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xLock(pFile, eLock);
}

/*
** Unlock an apnd-file.
*/
static int apndUnlock(sqlite3_file *pFile, int eLock){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xUnlock(pFile, eLock);
}

/*
** Check if another file-handle holds a RESERVED lock on an apnd-file.
*/
static int apndCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xCheckReservedLock(pFile, pResOut);
}

/*
** File control method. For custom operations on an apnd-file.
*/
static int apndFileControl(sqlite3_file *pFile, int op, void *pArg){
  ApndFile *paf = (ApndFile *)pFile;
  int rc;
  pFile = ORIGFILE(pFile);
  if( op==SQLITE_FCNTL_SIZE_HINT ) *(sqlite3_int64*)pArg += paf->iPgOne;
  rc = pFile->pMethods->xFileControl(pFile, op, pArg);
  if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){
    *(char**)pArg = sqlite3_mprintf("apnd(%lld)/%z", paf->iPgOne,*(char**)pArg);
  }
  return rc;
}

/*
** Return the sector-size in bytes for an apnd-file.
*/
static int apndSectorSize(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xSectorSize(pFile);
}

/*
** Return the device characteristic flags supported by an apnd-file.
*/
static int apndDeviceCharacteristics(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xDeviceCharacteristics(pFile);
}

/* Create a shared memory file mapping */
static int apndShmMap(
  sqlite3_file *pFile,
  int iPg,
  int pgsz,
  int bExtend,
  void volatile **pp
){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmMap(pFile,iPg,pgsz,bExtend,pp);
}

/* Perform locking on a shared-memory segment */
static int apndShmLock(sqlite3_file *pFile, int offset, int n, int flags){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmLock(pFile,offset,n,flags);
}

/* Memory barrier operation on shared memory */
static void apndShmBarrier(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  pFile->pMethods->xShmBarrier(pFile);
}

/* Unmap a shared memory segment */
static int apndShmUnmap(sqlite3_file *pFile, int deleteFlag){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmUnmap(pFile,deleteFlag);
}

/* Fetch a page of a memory-mapped file */
static int apndFetch(
  sqlite3_file *pFile,
  sqlite3_int64 iOfst,
  int iAmt,
  void **pp
){
  ApndFile *p = (ApndFile *)pFile;
  if( p->iMark < 0 || iOfst+iAmt > p->iMark ){
    return SQLITE_IOERR; /* Cannot read what is not yet there. */
  }
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xFetch(pFile, iOfst+p->iPgOne, iAmt, pp);
}

/* Release a memory-mapped page */
static int apndUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
  ApndFile *p = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xUnfetch(pFile, iOfst+p->iPgOne, pPage);
}

/*
** Try to read the append-mark off the end of a file.  Return the
** start of the appended database if the append-mark is present.
** If there is no valid append-mark, return -1;
**
** An append-mark is only valid if the NNNNNNNN start-of-database offset
** indicates that the appended database contains at least one page.  The
** start-of-database value must be a multiple of 512.
*/
static sqlite3_int64 apndReadMark(sqlite3_int64 sz, sqlite3_file *pFile){
  int rc, i;
  sqlite3_int64 iMark;
  int msbs = 8 * (APND_MARK_FOS_SZ-1);
  unsigned char a[APND_MARK_SIZE];

  if( APND_MARK_SIZE!=(sz & 0x1ff) ) return -1;
  rc = pFile->pMethods->xRead(pFile, a, APND_MARK_SIZE, sz-APND_MARK_SIZE);
  if( rc ) return -1;
  if( memcmp(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ)!=0 ) return -1;
  iMark = ((sqlite3_int64)(a[APND_MARK_PREFIX_SZ] & 0x7f)) << msbs;
  for(i=1; i<8; i++){
    msbs -= 8;
    iMark |= (sqlite3_int64)a[APND_MARK_PREFIX_SZ+i]<<msbs;
  }
  if( iMark > (sz - APND_MARK_SIZE - 512) ) return -1;
  if( iMark & 0x1ff ) return -1;
  return iMark;
}

static const char apvfsSqliteHdr[] = "SQLite format 3";
/*
** Check to see if the file is an appendvfs SQLite database file.
** Return true iff it is such. Parameter sz is the file's size.
*/
static int apndIsAppendvfsDatabase(sqlite3_int64 sz, sqlite3_file *pFile){
  int rc;
  char zHdr[16];
  sqlite3_int64 iMark = apndReadMark(sz, pFile);
  if( iMark>=0 ){
    /* If file has the correct end-marker, the expected odd size, and the
    ** SQLite DB type marker where the end-marker puts it, then it
    ** is an appendvfs database.
    */
    rc = pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), iMark);
    if( SQLITE_OK==rc
     && memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))==0
     && (sz & 0x1ff) == APND_MARK_SIZE
     && sz>=512+APND_MARK_SIZE
    ){
      return 1; /* It's an appendvfs database */
    }
  }
  return 0;
}

/*
** Check to see if the file is an ordinary SQLite database file.
** Return true iff so. Parameter sz is the file's size.
*/
static int apndIsOrdinaryDatabaseFile(sqlite3_int64 sz, sqlite3_file *pFile){
  char zHdr[16];
  if( apndIsAppendvfsDatabase(sz, pFile) /* rule 2 */
   || (sz & 0x1ff) != 0
   || SQLITE_OK!=pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), 0)
   || memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))!=0
  ){
    return 0;
  }else{
    return 1;
  }
}

/*
** Open an apnd file handle.
*/
static int apndOpen(
  sqlite3_vfs *pApndVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  ApndFile *pApndFile = (ApndFile*)pFile;
  sqlite3_file *pBaseFile = ORIGFILE(pFile);
  sqlite3_vfs *pBaseVfs = ORIGVFS(pApndVfs);
  int rc;
  sqlite3_int64 sz = 0;
  if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){
    /* The appendvfs is not to be used for transient or temporary databases.
    ** Just use the base VFS open to initialize the given file object and
    ** open the underlying file. (Appendvfs is then unused for this file.)
    */
    return pBaseVfs->xOpen(pBaseVfs, zName, pFile, flags, pOutFlags);
  }
  memset(pApndFile, 0, sizeof(ApndFile));
  pFile->pMethods = &apnd_io_methods;
  pApndFile->iMark = -1;    /* Append mark not yet written */

  rc = pBaseVfs->xOpen(pBaseVfs, zName, pBaseFile, flags, pOutFlags);
  if( rc==SQLITE_OK ){
    rc = pBaseFile->pMethods->xFileSize(pBaseFile, &sz);
    if( rc ){
      pBaseFile->pMethods->xClose(pBaseFile);
    }
  }
  if( rc ){
    pFile->pMethods = 0;
    return rc;
  }
  if( apndIsOrdinaryDatabaseFile(sz, pBaseFile) ){
    /* The file being opened appears to be just an ordinary DB. Copy
    ** the base dispatch-table so this instance mimics the base VFS. 
    */
    memmove(pApndFile, pBaseFile, pBaseVfs->szOsFile);
    return SQLITE_OK;
  }
  pApndFile->iPgOne = apndReadMark(sz, pFile);
  if( pApndFile->iPgOne>=0 ){
    pApndFile->iMark = sz - APND_MARK_SIZE; /* Append mark found */
    return SQLITE_OK;
  }
  if( (flags & SQLITE_OPEN_CREATE)==0 ){
    pBaseFile->pMethods->xClose(pBaseFile);
    rc = SQLITE_CANTOPEN;
    pFile->pMethods = 0;
  }else{
    /* Round newly added appendvfs location to #define'd page boundary. 
    ** Note that nothing has yet been written to the underlying file.
    ** The append mark will be written along with first content write.
    ** Until then, paf->iMark value indicates it is not yet written.
    */
    pApndFile->iPgOne = APND_START_ROUNDUP(sz);
  }
  return rc;
}

/*
** Delete an apnd file.
** For an appendvfs, this could mean delete the appendvfs portion,
** leaving the appendee as it was before it gained an appendvfs.
** For now, this code deletes the underlying file too.
*/
static int apndDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync);
}

/*
** All other VFS methods are pass-thrus.
*/
static int apndAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  return ORIGVFS(pVfs)->xAccess(ORIGVFS(pVfs), zPath, flags, pResOut);
}
static int apndFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nOut, 
  char *zOut
){
  return ORIGVFS(pVfs)->xFullPathname(ORIGVFS(pVfs),zPath,nOut,zOut);
}
static void *apndDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath);
}
static void apndDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg);
}
static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
  return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym);
}
static void apndDlClose(sqlite3_vfs *pVfs, void *pHandle){
  ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle);
}
static int apndRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);
}
static int apndSleep(sqlite3_vfs *pVfs, int nMicro){
  return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);
}
static int apndCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);
}
static int apndGetLastError(sqlite3_vfs *pVfs, int a, char *b){
  return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
}
static int apndCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
  return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
}
static int apndSetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_syscall_ptr pCall
){
  return ORIGVFS(pVfs)->xSetSystemCall(ORIGVFS(pVfs),zName,pCall);
}
static sqlite3_syscall_ptr apndGetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName
){
  return ORIGVFS(pVfs)->xGetSystemCall(ORIGVFS(pVfs),zName);
}
static const char *apndNextSystemCall(sqlite3_vfs *pVfs, const char *zName){
  return ORIGVFS(pVfs)->xNextSystemCall(ORIGVFS(pVfs), zName);
}

  
#ifdef _WIN32

#endif
/* 
** This routine is called when the extension is loaded.
** Register the new VFS.
*/
int sqlite3_appendvfs_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  sqlite3_vfs *pOrig;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;
  (void)db;
  pOrig = sqlite3_vfs_find(0);
  if( pOrig==0 ) return SQLITE_ERROR;
  apnd_vfs.iVersion = pOrig->iVersion;
  apnd_vfs.pAppData = pOrig;
  apnd_vfs.szOsFile = pOrig->szOsFile + sizeof(ApndFile);
  rc = sqlite3_vfs_register(&apnd_vfs, 0);
#ifdef APPENDVFS_TEST
  if( rc==SQLITE_OK ){
    rc = sqlite3_auto_extension((void(*)(void))apndvfsRegister);
  }
#endif
  if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
  return rc;
}

/************************* End ext/misc/appendvfs.c ********************/
#endif
#ifdef SQLITE_HAVE_ZLIB
/************************* Begin ext/misc/zipfile.c ******************/
/*
** 2017-12-26
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements a virtual table for reading and writing ZIP archive
** files.
**
** Usage example:
**
**     SELECT name, sz, datetime(mtime,'unixepoch') FROM zipfile($filename);
**
** Current limitations:
**
**    *  No support for encryption
**    *  No support for ZIP archives spanning multiple files
**    *  No support for zip64 extensions
**    *  Only the "inflate/deflate" (zlib) compression method is supported
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <stdio.h>
#include <string.h>
#include <assert.h>
#ifndef SQLITE_NO_STDINT
#  include <stdint.h>
#endif

#include <zlib.h>

/* When used as part of the CLI, the sqlite3_stdio.h module will have
** been included before this one. In that case use the sqlite3_stdio.h
** #defines.  If not, create our own for fopen().
*/
#ifndef _SQLITE3_STDIO_H_
# define sqlite3_fopen fopen
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE

#ifndef SQLITE_AMALGAMATION

#ifndef UINT32_TYPE
# ifdef HAVE_UINT32_T
#  define UINT32_TYPE uint32_t
# else
#  define UINT32_TYPE unsigned int
# endif
#endif
#ifndef UINT16_TYPE
# ifdef HAVE_UINT16_T
#  define UINT16_TYPE uint16_t
# else
#  define UINT16_TYPE unsigned short int
# endif
#endif
/* typedef sqlite3_int64 i64; */
/* typedef unsigned char u8; */
/* typedef UINT32_TYPE u32;           // 4-byte unsigned integer // */
/* typedef UINT16_TYPE u16;           // 2-byte unsigned integer // */
#ifndef MIN
# define MIN(A,B) ((A)<(B)?(A):(B))
#endif
#ifndef MAX
# define MAX(A,B) ((A)>(B)?(A):(B))
#endif

#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
# define SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS 1
#endif
#if defined(SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS)
# define ALWAYS(X)      (1)
# define NEVER(X)       (0)
#elif !defined(NDEBUG)
# define ALWAYS(X)      ((X)?1:(assert(0),0))
# define NEVER(X)       ((X)?(assert(0),1):0)
#else
# define ALWAYS(X)      (X)
# define NEVER(X)       (X)
#endif

#endif   /* SQLITE_AMALGAMATION */

/*
** Definitions for mode bitmasks S_IFDIR, S_IFREG and S_IFLNK.
**
** In some ways it would be better to obtain these values from system 
** header files. But, the dependency is undesirable and (a) these
** have been stable for decades, (b) the values are part of POSIX and
** are also made explicit in [man stat], and (c) are part of the 
** file format for zip archives.
*/
#ifndef S_IFDIR
# define S_IFDIR 0040000
#endif
#ifndef S_IFREG
# define S_IFREG 0100000
#endif
#ifndef S_IFLNK
# define S_IFLNK 0120000
#endif

static const char ZIPFILE_SCHEMA[] = 
  "CREATE TABLE y("
    "name PRIMARY KEY,"  /* 0: Name of file in zip archive */
    "mode,"              /* 1: POSIX mode for file */
    "mtime,"             /* 2: Last modification time (secs since 1970)*/
    "sz,"                /* 3: Size of object */
    "rawdata,"           /* 4: Raw data */
    "data,"              /* 5: Uncompressed data */
    "method,"            /* 6: Compression method (integer) */
    "z HIDDEN"           /* 7: Name of zip file */
  ") WITHOUT ROWID;";

#define ZIPFILE_F_COLUMN_IDX 7    /* Index of column "file" in the above */
#define ZIPFILE_MX_NAME (250)     /* Windows limitation on filename size */

/*
** The buffer should be large enough to contain 3 65536 byte strings - the
** filename, the extra field and the file comment.
*/
#define ZIPFILE_BUFFER_SIZE (200*1024)


/*
** Magic numbers used to read and write zip files.
**
** ZIPFILE_NEWENTRY_MADEBY:
**   Use this value for the "version-made-by" field in new zip file
**   entries. The upper byte indicates "unix", and the lower byte 
**   indicates that the zip file matches pkzip specification 3.0. 
**   This is what info-zip seems to do.
**
** ZIPFILE_NEWENTRY_REQUIRED:
**   Value for "version-required-to-extract" field of new entries.
**   Version 2.0 is required to support folders and deflate compression.
**
** ZIPFILE_NEWENTRY_FLAGS:
**   Value for "general-purpose-bit-flags" field of new entries. Bit
**   11 means "utf-8 filename and comment".
**
** ZIPFILE_SIGNATURE_CDS:
**   First 4 bytes of a valid CDS record.
**
** ZIPFILE_SIGNATURE_LFH:
**   First 4 bytes of a valid LFH record.
**
** ZIPFILE_SIGNATURE_EOCD
**   First 4 bytes of a valid EOCD record.
*/
#define ZIPFILE_EXTRA_TIMESTAMP   0x5455
#define ZIPFILE_NEWENTRY_MADEBY   ((3<<8) + 30)
#define ZIPFILE_NEWENTRY_REQUIRED 20
#define ZIPFILE_NEWENTRY_FLAGS    0x800
#define ZIPFILE_SIGNATURE_CDS     0x02014b50
#define ZIPFILE_SIGNATURE_LFH     0x04034b50
#define ZIPFILE_SIGNATURE_EOCD    0x06054b50

/*
** The sizes of the fixed-size part of each of the three main data 
** structures in a zip archive.
*/
#define ZIPFILE_LFH_FIXED_SZ      30
#define ZIPFILE_EOCD_FIXED_SZ     22
#define ZIPFILE_CDS_FIXED_SZ      46

/*
*** 4.3.16  End of central directory record:
***
***   end of central dir signature    4 bytes  (0x06054b50)
***   number of this disk             2 bytes
***   number of the disk with the
***   start of the central directory  2 bytes
***   total number of entries in the
***   central directory on this disk  2 bytes
***   total number of entries in
***   the central directory           2 bytes
***   size of the central directory   4 bytes
***   offset of start of central
***   directory with respect to
***   the starting disk number        4 bytes
***   .ZIP file comment length        2 bytes
***   .ZIP file comment       (variable size)
*/
typedef struct ZipfileEOCD ZipfileEOCD;
struct ZipfileEOCD {
  u16 iDisk;
  u16 iFirstDisk;
  u16 nEntry;
  u16 nEntryTotal;
  u32 nSize;
  u32 iOffset;
};

/*
*** 4.3.12  Central directory structure:
***
*** ...
***
***   central file header signature   4 bytes  (0x02014b50)
***   version made by                 2 bytes
***   version needed to extract       2 bytes
***   general purpose bit flag        2 bytes
***   compression method              2 bytes
***   last mod file time              2 bytes
***   last mod file date              2 bytes
***   crc-32                          4 bytes
***   compressed size                 4 bytes
***   uncompressed size               4 bytes
***   file name length                2 bytes
***   extra field length              2 bytes
***   file comment length             2 bytes
***   disk number start               2 bytes
***   internal file attributes        2 bytes
***   external file attributes        4 bytes
***   relative offset of local header 4 bytes
*/
typedef struct ZipfileCDS ZipfileCDS;
struct ZipfileCDS {
  u16 iVersionMadeBy;
  u16 iVersionExtract;
  u16 flags;
  u16 iCompression;
  u16 mTime;
  u16 mDate;
  u32 crc32;
  u32 szCompressed;
  u32 szUncompressed;
  u16 nFile;
  u16 nExtra;
  u16 nComment;
  u16 iDiskStart;
  u16 iInternalAttr;
  u32 iExternalAttr;
  u32 iOffset;
  char *zFile;                    /* Filename (sqlite3_malloc()) */
};

/*
*** 4.3.7  Local file header:
***
***   local file header signature     4 bytes  (0x04034b50)
***   version needed to extract       2 bytes
***   general purpose bit flag        2 bytes
***   compression method              2 bytes
***   last mod file time              2 bytes
***   last mod file date              2 bytes
***   crc-32                          4 bytes
***   compressed size                 4 bytes
***   uncompressed size               4 bytes
***   file name length                2 bytes
***   extra field length              2 bytes
***   
*/
typedef struct ZipfileLFH ZipfileLFH;
struct ZipfileLFH {
  u16 iVersionExtract;
  u16 flags;
  u16 iCompression;
  u16 mTime;
  u16 mDate;
  u32 crc32;
  u32 szCompressed;
  u32 szUncompressed;
  u16 nFile;
  u16 nExtra;
};

typedef struct ZipfileEntry ZipfileEntry;
struct ZipfileEntry {
  ZipfileCDS cds;            /* Parsed CDS record */
  u32 mUnixTime;             /* Modification time, in UNIX format */
  u8 *aExtra;                /* cds.nExtra+cds.nComment bytes of extra data */
  i64 iDataOff;              /* Offset to data in file (if aData==0) */
  u8 *aData;                 /* cds.szCompressed bytes of compressed data */
  ZipfileEntry *pNext;       /* Next element in in-memory CDS */
};

/* 
** Cursor type for zipfile tables.
*/
typedef struct ZipfileCsr ZipfileCsr;
struct ZipfileCsr {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  i64 iId;                   /* Cursor ID */
  u8 bEof;                   /* True when at EOF */
  u8 bNoop;                  /* If next xNext() call is no-op */

  /* Used outside of write transactions */
  FILE *pFile;               /* Zip file */
  i64 iNextOff;              /* Offset of next record in central directory */
  ZipfileEOCD eocd;          /* Parse of central directory record */

  ZipfileEntry *pFreeEntry;  /* Free this list when cursor is closed or reset */
  ZipfileEntry *pCurrent;    /* Current entry */
  ZipfileCsr *pCsrNext;      /* Next cursor on same virtual table */
};

typedef struct ZipfileTab ZipfileTab;
struct ZipfileTab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zFile;               /* Zip file this table accesses (may be NULL) */
  sqlite3 *db;               /* Host database connection */
  u8 *aBuffer;               /* Temporary buffer used for various tasks */

  ZipfileCsr *pCsrList;      /* List of cursors */
  i64 iNextCsrid;

  /* The following are used by write transactions only */
  ZipfileEntry *pFirstEntry; /* Linked list of all files (if pWriteFd!=0) */
  ZipfileEntry *pLastEntry;  /* Last element in pFirstEntry list */
  FILE *pWriteFd;            /* File handle open on zip archive */
  i64 szCurrent;             /* Current size of zip archive */
  i64 szOrig;                /* Size of archive at start of transaction */
};

/*
** Set the error message contained in context ctx to the results of
** vprintf(zFmt, ...).
*/
static void zipfileCtxErrorMsg(sqlite3_context *ctx, const char *zFmt, ...){
  char *zMsg = 0;
  va_list ap;
  va_start(ap, zFmt);
  zMsg = sqlite3_vmprintf(zFmt, ap);
  sqlite3_result_error(ctx, zMsg, -1);
  sqlite3_free(zMsg);
  va_end(ap);
}

/*
** If string zIn is quoted, dequote it in place. Otherwise, if the string
** is not quoted, do nothing.
*/
static void zipfileDequote(char *zIn){
  char q = zIn[0];
  if( q=='"' || q=='\'' || q=='`' || q=='[' ){
    int iIn = 1;
    int iOut = 0;
    if( q=='[' ) q = ']';
    while( ALWAYS(zIn[iIn]) ){
      char c = zIn[iIn++];
      if( c==q && zIn[iIn++]!=q ) break;
      zIn[iOut++] = c;
    }
    zIn[iOut] = '\0';
  }
}

/*
** Construct a new ZipfileTab virtual table object.
** 
**   argv[0]   -> module name  ("zipfile")
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> "column name" and other module argument fields.
*/
static int zipfileConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  size_t nByte = sizeof(ZipfileTab) + ZIPFILE_BUFFER_SIZE;
  size_t nFile = 0;
  const char *zFile = 0;
  ZipfileTab *pNew = 0;
  int rc;
  (void)pAux;

  /* If the table name is not "zipfile", require that the argument be
  ** specified. This stops zipfile tables from being created as:
  **
  **   CREATE VIRTUAL TABLE zzz USING zipfile();
  **
  ** It does not prevent:
  **
  **   CREATE VIRTUAL TABLE zipfile USING zipfile();
  */
  assert( 0==sqlite3_stricmp(argv[0], "zipfile") );
  if( (0!=sqlite3_stricmp(argv[2], "zipfile") && argc<4) || argc>4 ){
    *pzErr = sqlite3_mprintf("zipfile constructor requires one argument");
    return SQLITE_ERROR;
  }

  if( argc>3 ){
    zFile = argv[3];
    nFile = strlen(zFile)+1;
  }

  rc = sqlite3_declare_vtab(db, ZIPFILE_SCHEMA);
  if( rc==SQLITE_OK ){
    pNew = (ZipfileTab*)sqlite3_malloc64((i64)nByte+nFile);
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, nByte+nFile);
    pNew->db = db;
    pNew->aBuffer = (u8*)&pNew[1];
    if( zFile ){
      pNew->zFile = (char*)&pNew->aBuffer[ZIPFILE_BUFFER_SIZE];
      memcpy(pNew->zFile, zFile, nFile);
      zipfileDequote(pNew->zFile);
    }
  }
  sqlite3_vtab_config(db, SQLITE_VTAB_DIRECTONLY);
  *ppVtab = (sqlite3_vtab*)pNew;
  return rc;
}

/*
** Free the ZipfileEntry structure indicated by the only argument.
*/
static void zipfileEntryFree(ZipfileEntry *p){
  if( p ){
    sqlite3_free(p->cds.zFile);
    sqlite3_free(p);
  }
}

/*
** Release resources that should be freed at the end of a write 
** transaction.
*/
static void zipfileCleanupTransaction(ZipfileTab *pTab){
  ZipfileEntry *pEntry;
  ZipfileEntry *pNext;

  if( pTab->pWriteFd ){
    fclose(pTab->pWriteFd);
    pTab->pWriteFd = 0;
  }
  for(pEntry=pTab->pFirstEntry; pEntry; pEntry=pNext){
    pNext = pEntry->pNext;
    zipfileEntryFree(pEntry);
  }
  pTab->pFirstEntry = 0;
  pTab->pLastEntry = 0;
  pTab->szCurrent = 0;
  pTab->szOrig = 0;
}

/*
** This method is the destructor for zipfile vtab objects.
*/
static int zipfileDisconnect(sqlite3_vtab *pVtab){
  zipfileCleanupTransaction((ZipfileTab*)pVtab);
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new ZipfileCsr object.
*/
static int zipfileOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCsr){
  ZipfileTab *pTab = (ZipfileTab*)p;
  ZipfileCsr *pCsr;
  pCsr = sqlite3_malloc64(sizeof(*pCsr));
  *ppCsr = (sqlite3_vtab_cursor*)pCsr;
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }
  memset(pCsr, 0, sizeof(*pCsr));
  pCsr->iId = ++pTab->iNextCsrid;
  pCsr->pCsrNext = pTab->pCsrList;
  pTab->pCsrList = pCsr;
  return SQLITE_OK;
}

/*
** Reset a cursor back to the state it was in when first returned
** by zipfileOpen().
*/
static void zipfileResetCursor(ZipfileCsr *pCsr){
  ZipfileEntry *p;
  ZipfileEntry *pNext;

  pCsr->bEof = 0;
  if( pCsr->pFile ){
    fclose(pCsr->pFile);
    pCsr->pFile = 0;
    zipfileEntryFree(pCsr->pCurrent);
    pCsr->pCurrent = 0;
  }

  for(p=pCsr->pFreeEntry; p; p=pNext){
    pNext = p->pNext;
    zipfileEntryFree(p);
  }
}

/*
** Destructor for an ZipfileCsr.
*/
static int zipfileClose(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  ZipfileTab *pTab = (ZipfileTab*)(pCsr->base.pVtab);
  ZipfileCsr **pp;
  zipfileResetCursor(pCsr);

  /* Remove this cursor from the ZipfileTab.pCsrList list. */
  for(pp=&pTab->pCsrList; *pp!=pCsr; pp=&((*pp)->pCsrNext));
  *pp = pCsr->pCsrNext;

  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Set the error message for the virtual table associated with cursor
** pCsr to the results of vprintf(zFmt, ...).
*/
static void zipfileTableErr(ZipfileTab *pTab, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  sqlite3_free(pTab->base.zErrMsg);
  pTab->base.zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}
static void zipfileCursorErr(ZipfileCsr *pCsr, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  sqlite3_free(pCsr->base.pVtab->zErrMsg);
  pCsr->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}

/*
** Read nRead bytes of data from offset iOff of file pFile into buffer
** aRead[]. Return SQLITE_OK if successful, or an SQLite error code
** otherwise. 
**
** If an error does occur, output variable (*pzErrmsg) may be set to point
** to an English language error message. It is the responsibility of the
** caller to eventually free this buffer using
** sqlite3_free().
*/
static int zipfileReadData(
  FILE *pFile,                    /* Read from this file */
  u8 *aRead,                      /* Read into this buffer */
  i64 nRead,                      /* Number of bytes to read */
  i64 iOff,                       /* Offset to read from */
  char **pzErrmsg                 /* OUT: Error message (from sqlite3_malloc) */
){
  size_t n;
  fseek(pFile, (long)iOff, SEEK_SET);
  n = fread(aRead, 1, (long)nRead, pFile);
  if( n!=(size_t)nRead ){
    sqlite3_free(*pzErrmsg);
    *pzErrmsg = sqlite3_mprintf("error in fread()");
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}

static int zipfileAppendData(
  ZipfileTab *pTab,
  const u8 *aWrite,
  int nWrite
){
  if( nWrite>0 ){
    size_t n = nWrite;
    fseek(pTab->pWriteFd, (long)pTab->szCurrent, SEEK_SET);
    n = fwrite(aWrite, 1, nWrite, pTab->pWriteFd);
    if( (int)n!=nWrite ){
      zipfileTableErr(pTab,"error in fwrite()");
      return SQLITE_ERROR;
    }
    pTab->szCurrent += nWrite;
  }
  return SQLITE_OK;
}

/*
** Read and return a 16-bit little-endian unsigned integer from buffer aBuf.
*/
static u16 zipfileGetU16(const u8 *aBuf){
  return (aBuf[1] << 8) + aBuf[0];
}

/*
** Read and return a 32-bit little-endian unsigned integer from buffer aBuf.
*/
static u32 zipfileGetU32(const u8 *aBuf){
  if( aBuf==0 ) return 0;
  return ((u32)(aBuf[3]) << 24)
       + ((u32)(aBuf[2]) << 16)
       + ((u32)(aBuf[1]) <<  8)
       + ((u32)(aBuf[0]) <<  0);
}

/*
** Write a 16-bit little endiate integer into buffer aBuf.
*/
static void zipfilePutU16(u8 *aBuf, u16 val){
  aBuf[0] = val & 0xFF;
  aBuf[1] = (val>>8) & 0xFF;
}

/*
** Write a 32-bit little endiate integer into buffer aBuf.
*/
static void zipfilePutU32(u8 *aBuf, u32 val){
  aBuf[0] = val & 0xFF;
  aBuf[1] = (val>>8) & 0xFF;
  aBuf[2] = (val>>16) & 0xFF;
  aBuf[3] = (val>>24) & 0xFF;
}

#define zipfileRead32(aBuf) ( aBuf+=4, zipfileGetU32(aBuf-4) )
#define zipfileRead16(aBuf) ( aBuf+=2, zipfileGetU16(aBuf-2) )

#define zipfileWrite32(aBuf,val) { zipfilePutU32(aBuf,val); aBuf+=4; }
#define zipfileWrite16(aBuf,val) { zipfilePutU16(aBuf,val); aBuf+=2; }

/*
** Magic numbers used to read CDS records.
*/
#define ZIPFILE_CDS_NFILE_OFF        28
#define ZIPFILE_CDS_SZCOMPRESSED_OFF 20

/*
** Decode the CDS record in buffer aBuf into (*pCDS). Return SQLITE_ERROR
** if the record is not well-formed, or SQLITE_OK otherwise.
*/
static int zipfileReadCDS(u8 *aBuf, ZipfileCDS *pCDS){
  u8 *aRead = aBuf;
  u32 sig = zipfileRead32(aRead);
  int rc = SQLITE_OK;
  if( sig!=ZIPFILE_SIGNATURE_CDS ){
    rc = SQLITE_ERROR;
  }else{
    pCDS->iVersionMadeBy = zipfileRead16(aRead);
    pCDS->iVersionExtract = zipfileRead16(aRead);
    pCDS->flags = zipfileRead16(aRead);
    pCDS->iCompression = zipfileRead16(aRead);
    pCDS->mTime = zipfileRead16(aRead);
    pCDS->mDate = zipfileRead16(aRead);
    pCDS->crc32 = zipfileRead32(aRead);
    pCDS->szCompressed = zipfileRead32(aRead);
    pCDS->szUncompressed = zipfileRead32(aRead);
    assert( aRead==&aBuf[ZIPFILE_CDS_NFILE_OFF] );
    pCDS->nFile = zipfileRead16(aRead);
    pCDS->nExtra = zipfileRead16(aRead);
    pCDS->nComment = zipfileRead16(aRead);
    pCDS->iDiskStart = zipfileRead16(aRead);
    pCDS->iInternalAttr = zipfileRead16(aRead);
    pCDS->iExternalAttr = zipfileRead32(aRead);
    pCDS->iOffset = zipfileRead32(aRead);
    assert( aRead==&aBuf[ZIPFILE_CDS_FIXED_SZ] );
  }

  return rc;
}

/*
** Decode the LFH record in buffer aBuf into (*pLFH). Return SQLITE_ERROR
** if the record is not well-formed, or SQLITE_OK otherwise.
*/
static int zipfileReadLFH(
  u8 *aBuffer,
  ZipfileLFH *pLFH
){
  u8 *aRead = aBuffer;
  int rc = SQLITE_OK;

  u32 sig = zipfileRead32(aRead);
  if( sig!=ZIPFILE_SIGNATURE_LFH ){
    rc = SQLITE_ERROR;
  }else{
    pLFH->iVersionExtract = zipfileRead16(aRead);
    pLFH->flags = zipfileRead16(aRead);
    pLFH->iCompression = zipfileRead16(aRead);
    pLFH->mTime = zipfileRead16(aRead);
    pLFH->mDate = zipfileRead16(aRead);
    pLFH->crc32 = zipfileRead32(aRead);
    pLFH->szCompressed = zipfileRead32(aRead);
    pLFH->szUncompressed = zipfileRead32(aRead);
    pLFH->nFile = zipfileRead16(aRead);
    pLFH->nExtra = zipfileRead16(aRead);
    if( pLFH->nFile>ZIPFILE_MX_NAME ) rc = SQLITE_ERROR;
  }
  return rc;
}


/*
** Buffer aExtra (size nExtra bytes) contains zip archive "extra" fields.
** Scan through this buffer to find an "extra-timestamp" field. If one
** exists, extract the 32-bit modification-timestamp from it and store
** the value in output parameter *pmTime.
**
** Zero is returned if no extra-timestamp record could be found (and so
** *pmTime is left unchanged), or non-zero otherwise.
**
** The general format of an extra field is:
**
**   Header ID    2 bytes
**   Data Size    2 bytes
**   Data         N bytes
*/
static int zipfileScanExtra(u8 *aExtra, int nExtra, u32 *pmTime){
  int ret = 0;
  u8 *p = aExtra;
  u8 *pEnd = &aExtra[nExtra];

  /* Stop when there are less than 9 bytes left to scan in the buffer. This
  ** is because the timestamp field requires exactly 9 bytes - 4 bytes of
  ** header fields and 5 bytes of data. If there are less than 9 bytes 
  ** remaining, either it is some other field or else the extra data
  ** is corrupt. Either way, do not process it.  */
  while( p+(2*sizeof(u16) + 1 + sizeof(u32))<=pEnd ){
    u16 id = zipfileRead16(p);
    u16 nByte = zipfileRead16(p);

    switch( id ){
      case ZIPFILE_EXTRA_TIMESTAMP: {
        u8 b = p[0];
        if( b & 0x01 ){     /* 0x01 -> modtime is present */
          *pmTime = zipfileGetU32(&p[1]);
          ret = 1;
        }
        break;
      }
    }

    p += nByte;
  }
  return ret;
}

/*
** Convert the standard MS-DOS timestamp stored in the mTime and mDate
** fields of the CDS structure passed as the only argument to a 32-bit
** UNIX seconds-since-the-epoch timestamp. Return the result.
**
** "Standard" MS-DOS time format:
**
**   File modification time:
**     Bits 00-04: seconds divided by 2
**     Bits 05-10: minute
**     Bits 11-15: hour
**   File modification date:
**     Bits 00-04: day
**     Bits 05-08: month (1-12)
**     Bits 09-15: years from 1980 
**
** https://msdn.microsoft.com/en-us/library/9kkf9tah.aspx
*/
static u32 zipfileMtime(ZipfileCDS *pCDS){
  int Y,M,D,X1,X2,A,B,sec,min,hr;
  i64 JDsec;
  Y = (1980 + ((pCDS->mDate >> 9) & 0x7F));
  M = ((pCDS->mDate >> 5) & 0x0F);
  D = (pCDS->mDate & 0x1F);
  sec = (pCDS->mTime & 0x1F)*2;
  min = (pCDS->mTime >> 5) & 0x3F;
  hr = (pCDS->mTime >> 11) & 0x1F;
  if( M<=2 ){
    Y--;
    M += 12;
  }
  X1 = 36525*(Y+4716)/100;
  X2 = 306001*(M+1)/10000;
  A = Y/100;
  B = 2 - A + (A/4);
  JDsec = (i64)((X1 + X2 + D + B - 1524.5)*86400) + hr*3600 + min*60 + sec;
  return (u32)(JDsec - (i64)24405875*(i64)8640);
}

/*
** The opposite of zipfileMtime(). This function populates the mTime and
** mDate fields of the CDS structure passed as the first argument according
** to the UNIX timestamp value passed as the second.
*/
static void zipfileMtimeToDos(ZipfileCDS *pCds, u32 mUnixTime){
  /* Convert unix timestamp to JD (2440588 is noon on 1/1/1970) */
  i64 JD = (i64)2440588 + mUnixTime / (24*60*60);

  int A, B, C, D, E;
  int yr, mon, day;
  int hr, min, sec;

  A = (int)((JD - 1867216.25)/36524.25);
  A = (int)(JD + 1 + A - (A/4));
  B = A + 1524;
  C = (int)((B - 122.1)/365.25);
  D = (36525*(C&32767))/100;
  E = (int)((B-D)/30.6001);

  day = B - D - (int)(30.6001*E);
  mon = (E<14 ? E-1 : E-13);
  yr = mon>2 ? C-4716 : C-4715;

  hr = (mUnixTime % (24*60*60)) / (60*60);
  min = (mUnixTime % (60*60)) / 60;
  sec = (mUnixTime % 60);

  if( yr>=1980 ){
    pCds->mDate = (u16)(day + (mon << 5) + ((yr-1980) << 9));
    pCds->mTime = (u16)(sec/2 + (min<<5) + (hr<<11));
  }else{
    pCds->mDate = pCds->mTime = 0;
  }

  assert( mUnixTime<315507600 
       || mUnixTime==zipfileMtime(pCds) 
       || ((mUnixTime % 2) && mUnixTime-1==zipfileMtime(pCds)) 
       /* || (mUnixTime % 2) */
  );
}

/*
** Set (*pzErr) to point to a buffer from sqlite3_malloc() containing a 
** generic corruption message and return SQLITE_CORRUPT;
*/
static int zipfileCorrupt(char **pzErr){
  sqlite3_free(*pzErr);
  *pzErr = sqlite3_mprintf("zip archive is corrupt");
  return SQLITE_CORRUPT;
}

/*
** If aBlob is not NULL, then it is a pointer to a buffer (nBlob bytes in
** size) containing an entire zip archive image. Or, if aBlob is NULL,
** then pFile is a file-handle open on a zip file. In either case, this
** function creates a ZipfileEntry object based on the zip archive entry
** for which the CDS record is at offset iOff.
**
** If successful, SQLITE_OK is returned and (*ppEntry) set to point to
** the new object. Otherwise, an SQLite error code is returned and the
** final value of (*ppEntry) undefined.
*/
static int zipfileGetEntry(
  ZipfileTab *pTab,               /* Store any error message here */
  const u8 *aBlob,                /* Pointer to in-memory file image */
  i64 nBlob,                      /* Size of aBlob[] in bytes */
  FILE *pFile,                    /* If aBlob==0, read from this file */
  i64 iOff,                       /* Offset of CDS record */
  ZipfileEntry **ppEntry          /* OUT: Pointer to new object */
){
  u8 *aRead;
  char **pzErr = &pTab->base.zErrMsg;
  int rc = SQLITE_OK;

  if( aBlob==0 ){
    aRead = pTab->aBuffer;
    rc = zipfileReadData(pFile, aRead, ZIPFILE_CDS_FIXED_SZ, iOff, pzErr);
  }else{
    if( (iOff+ZIPFILE_CDS_FIXED_SZ)>nBlob ){
      /* Not enough data for the CDS structure. Corruption. */
      return zipfileCorrupt(pzErr);
    }
    aRead = (u8*)&aBlob[iOff];
  }

  if( rc==SQLITE_OK ){
    size_t nAlloc;
    ZipfileEntry *pNew;

    int nFile = zipfileGetU16(&aRead[ZIPFILE_CDS_NFILE_OFF]);
    int nExtra = zipfileGetU16(&aRead[ZIPFILE_CDS_NFILE_OFF+2]);
    nExtra += zipfileGetU16(&aRead[ZIPFILE_CDS_NFILE_OFF+4]);

    nAlloc = sizeof(ZipfileEntry) + nExtra;
    if( aBlob ){
      nAlloc += zipfileGetU32(&aRead[ZIPFILE_CDS_SZCOMPRESSED_OFF]);
    }

    pNew = (ZipfileEntry*)sqlite3_malloc(nAlloc);
    if( pNew==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pNew, 0, sizeof(ZipfileEntry));
      rc = zipfileReadCDS(aRead, &pNew->cds);
      if( rc!=SQLITE_OK ){
        zipfileTableErr(pTab, "failed to read CDS at offset %lld", iOff);
      }else if( aBlob==0 ){
        rc = zipfileReadData(
            pFile, aRead, nExtra+nFile, iOff+ZIPFILE_CDS_FIXED_SZ, pzErr
        );
      }else{
        aRead = (u8*)&aBlob[iOff + ZIPFILE_CDS_FIXED_SZ];
        if( (iOff + ZIPFILE_CDS_FIXED_SZ + nFile + nExtra)>nBlob ){
          rc = zipfileCorrupt(pzErr);
        }
      }
    }

    if( rc==SQLITE_OK ){
      u32 *pt = &pNew->mUnixTime;
      pNew->cds.zFile = sqlite3_mprintf("%.*s", nFile, aRead); 
      pNew->aExtra = (u8*)&pNew[1];
      memcpy(pNew->aExtra, &aRead[nFile], nExtra);
      if( pNew->cds.zFile==0 ){
        rc = SQLITE_NOMEM;
      }else if( 0==zipfileScanExtra(&aRead[nFile], pNew->cds.nExtra, pt) ){
        pNew->mUnixTime = zipfileMtime(&pNew->cds);
      }
    }

    if( rc==SQLITE_OK ){
      static const int szFix = ZIPFILE_LFH_FIXED_SZ;
      ZipfileLFH lfh;
      if( pFile ){
        rc = zipfileReadData(pFile, aRead, szFix, pNew->cds.iOffset, pzErr);
      }else{
        aRead = (u8*)&aBlob[pNew->cds.iOffset];
        if( ((i64)pNew->cds.iOffset + ZIPFILE_LFH_FIXED_SZ)>nBlob ){
          rc = zipfileCorrupt(pzErr);
        }
      }

      memset(&lfh, 0, sizeof(lfh));
      if( rc==SQLITE_OK ) rc = zipfileReadLFH(aRead, &lfh);
      if( rc==SQLITE_OK ){
        pNew->iDataOff =  (i64)pNew->cds.iOffset + ZIPFILE_LFH_FIXED_SZ;
        pNew->iDataOff += lfh.nFile + lfh.nExtra;
        if( aBlob && pNew->cds.szCompressed ){
          if( pNew->iDataOff + pNew->cds.szCompressed > nBlob ){
            rc = zipfileCorrupt(pzErr);
          }else{
            pNew->aData = &pNew->aExtra[nExtra];
            memcpy(pNew->aData, &aBlob[pNew->iDataOff], pNew->cds.szCompressed);
          }
        }
      }else{
        zipfileTableErr(pTab, "failed to read LFH at offset %d", 
            (int)pNew->cds.iOffset
        );
      }
    }

    if( rc!=SQLITE_OK ){
      zipfileEntryFree(pNew);
    }else{
      *ppEntry = pNew;
    }
  }

  return rc;
}

/*
** Advance an ZipfileCsr to its next row of output.
*/
static int zipfileNext(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  int rc = SQLITE_OK;

  if( pCsr->pFile ){
    i64 iEof = (i64)pCsr->eocd.iOffset + (i64)pCsr->eocd.nSize;
    zipfileEntryFree(pCsr->pCurrent);
    pCsr->pCurrent = 0;
    if( pCsr->iNextOff>=iEof ){
      pCsr->bEof = 1;
    }else{
      ZipfileEntry *p = 0;
      ZipfileTab *pTab = (ZipfileTab*)(cur->pVtab);
      rc = zipfileGetEntry(pTab, 0, 0, pCsr->pFile, pCsr->iNextOff, &p);
      if( rc==SQLITE_OK ){
        pCsr->iNextOff += ZIPFILE_CDS_FIXED_SZ;
        pCsr->iNextOff += (int)p->cds.nExtra + p->cds.nFile + p->cds.nComment;
      }
      pCsr->pCurrent = p;
    }
  }else{
    if( !pCsr->bNoop ){
      pCsr->pCurrent = pCsr->pCurrent->pNext;
    }
    if( pCsr->pCurrent==0 ){
      pCsr->bEof = 1;
    }
  }

  pCsr->bNoop = 0;
  return rc;
}

static void zipfileFree(void *p) { 
  sqlite3_free(p); 
}

/*
** Buffer aIn (size nIn bytes) contains compressed data. Uncompressed, the
** size is nOut bytes. This function uncompresses the data and sets the
** return value in context pCtx to the result (a blob).
**
** If an error occurs, an error code is left in pCtx instead.
*/
static void zipfileInflate(
  sqlite3_context *pCtx,          /* Store result here */
  const u8 *aIn,                  /* Compressed data */
  int nIn,                        /* Size of buffer aIn[] in bytes */
  int nOut                        /* Expected output size */
){
  u8 *aRes = sqlite3_malloc64(nOut);
  if( aRes==0 ){
    sqlite3_result_error_nomem(pCtx);
  }else{
    int err;
    z_stream str;
    memset(&str, 0, sizeof(str));

    str.next_in = (Byte*)aIn;
    str.avail_in = nIn;
    str.next_out = (Byte*)aRes;
    str.avail_out = nOut;

    err = inflateInit2(&str, -15);
    if( err!=Z_OK ){
      zipfileCtxErrorMsg(pCtx, "inflateInit2() failed (%d)", err);
    }else{
      err = inflate(&str, Z_NO_FLUSH);
      if( err!=Z_STREAM_END ){
        zipfileCtxErrorMsg(pCtx, "inflate() failed (%d)", err);
      }else{
        sqlite3_result_blob(pCtx, aRes, (int)str.total_out, zipfileFree);
        aRes = 0;
      }
    }
    sqlite3_free(aRes);
    inflateEnd(&str);
  }
}

/*
** Buffer aIn (size nIn bytes) contains uncompressed data. This function
** compresses it and sets (*ppOut) to point to a buffer containing the
** compressed data. The caller is responsible for eventually calling
** sqlite3_free() to release buffer (*ppOut). Before returning, (*pnOut) 
** is set to the size of buffer (*ppOut) in bytes.
**
** If no error occurs, SQLITE_OK is returned. Otherwise, an SQLite error
** code is returned and an error message left in virtual-table handle
** pTab. The values of (*ppOut) and (*pnOut) are left unchanged in this
** case.
*/
static int zipfileDeflate(
  const u8 *aIn, size_t nIn,         /* Input */
  u8 **ppOut, size_t *pnOut,         /* Output */
  char **pzErr                    /* OUT: Error message */
){
  int rc = SQLITE_OK;
  size_t nAlloc;
  z_stream str;
  u8 *aOut;

  memset(&str, 0, sizeof(str));
  str.next_in = (Bytef*)aIn;
  str.avail_in = nIn;
  deflateInit2(&str, 9, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);

  nAlloc = deflateBound(&str, nIn);
  aOut = (u8*)sqlite3_malloc(nAlloc);
  if( aOut==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int res;
    str.next_out = aOut;
    str.avail_out = nAlloc;
    res = deflate(&str, Z_FINISH);
    if( res==Z_STREAM_END ){
      *ppOut = aOut;
      *pnOut = str.total_out;
    }else{
      sqlite3_free(aOut);
      *pzErr = sqlite3_mprintf("zipfile: deflate() error");
      rc = SQLITE_ERROR;
    }
    deflateEnd(&str);
  }

  return rc;
}


/*
** Return values of columns for the row at which the series_cursor
** is currently pointing.
*/
static int zipfileColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  ZipfileCDS *pCDS = &pCsr->pCurrent->cds;
  int rc = SQLITE_OK;
  switch( i ){
    case 0:   /* name */
      sqlite3_result_text(ctx, pCDS->zFile, -1, SQLITE_TRANSIENT);
      break;
    case 1:   /* mode */
      /* TODO: Whether or not the following is correct surely depends on
      ** the platform on which the archive was created.  */
      sqlite3_result_int(ctx, pCDS->iExternalAttr >> 16);
      break;
    case 2: { /* mtime */
      sqlite3_result_int64(ctx, pCsr->pCurrent->mUnixTime);
      break;
    }
    case 3: { /* sz */
      if( sqlite3_vtab_nochange(ctx)==0 ){
        sqlite3_result_int64(ctx, pCDS->szUncompressed);
      }
      break;
    }
    case 4:   /* rawdata */
      if( sqlite3_vtab_nochange(ctx) ) break;
    case 5: { /* data */
      if( i==4 || pCDS->iCompression==0 || pCDS->iCompression==8 ){
        size_t sz = pCDS->szCompressed;
        size_t szFinal = pCDS->szUncompressed;
        if( szFinal>0 ){
          u8 *aBuf;
          u8 *aFree = 0;
          if( pCsr->pCurrent->aData ){
            aBuf = pCsr->pCurrent->aData;
          }else{
            aBuf = aFree = sqlite3_malloc(sz);
            if( aBuf==0 ){
              rc = SQLITE_NOMEM;
            }else{
              FILE *pFile = pCsr->pFile;
              if( pFile==0 ){
                pFile = ((ZipfileTab*)(pCsr->base.pVtab))->pWriteFd;
              }
              rc = zipfileReadData(pFile, aBuf, sz, pCsr->pCurrent->iDataOff,
                  &pCsr->base.pVtab->zErrMsg
              );
            }
          }
          if( rc==SQLITE_OK ){
            if( i==5 && pCDS->iCompression ){
              zipfileInflate(ctx, aBuf, sz, szFinal);
            }else{
              sqlite3_result_blob(ctx, aBuf, sz, SQLITE_TRANSIENT);
            }
          }
          sqlite3_free(aFree);
        }else{
          /* Figure out if this is a directory or a zero-sized file. Consider
          ** it to be a directory either if the mode suggests so, or if
          ** the final character in the name is '/'.  */
          u32 mode = pCDS->iExternalAttr >> 16;
          if( !(mode & S_IFDIR)
           && pCDS->nFile>=1
           && pCDS->zFile[pCDS->nFile-1]!='/'
          ){
            sqlite3_result_blob(ctx, "", 0, SQLITE_STATIC);
          }
        }
      }
      break;
    }
    case 6:   /* method */
      sqlite3_result_int(ctx, pCDS->iCompression);
      break;
    default:  /* z */
      assert( i==7 );
      sqlite3_result_int64(ctx, pCsr->iId);
      break;
  }

  return rc;
}

/*
** Return TRUE if the cursor is at EOF.
*/
static int zipfileEof(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  return pCsr->bEof;
}

/*
** If aBlob is not NULL, then it points to a buffer nBlob bytes in size
** containing an entire zip archive image. Or, if aBlob is NULL, then pFile
** is guaranteed to be a file-handle open on a zip file.
**
** This function attempts to locate the EOCD record within the zip archive
** and populate *pEOCD with the results of decoding it. SQLITE_OK is
** returned if successful. Otherwise, an SQLite error code is returned and
** an English language error message may be left in virtual-table pTab.
*/
static int zipfileReadEOCD(
  ZipfileTab *pTab,               /* Return errors here */
  const u8 *aBlob,                /* Pointer to in-memory file image */
  i64 nBlob,                      /* Size of aBlob[] in bytes */
  FILE *pFile,                    /* Read from this file if aBlob==0 */
  ZipfileEOCD *pEOCD              /* Object to populate */
){
  u8 *aRead = pTab->aBuffer;      /* Temporary buffer */
  i64 nRead;                      /* Bytes to read from file */
  int rc = SQLITE_OK;

  memset(pEOCD, 0, sizeof(ZipfileEOCD));
  if( aBlob==0 ){
    i64 iOff;                     /* Offset to read from */
    i64 szFile;                   /* Total size of file in bytes */
    fseek(pFile, 0, SEEK_END);
    szFile = (i64)ftell(pFile);
    if( szFile==0 ){
      return SQLITE_OK;
    }
    nRead = (int)(MIN(szFile, ZIPFILE_BUFFER_SIZE));
    iOff = szFile - nRead;
    rc = zipfileReadData(pFile, aRead, nRead, iOff, &pTab->base.zErrMsg);
  }else{
    nRead = (int)(MIN(nBlob, ZIPFILE_BUFFER_SIZE));
    aRead = (u8*)&aBlob[nBlob-nRead];
  }

  if( rc==SQLITE_OK ){
    i64 i;

    /* Scan backwards looking for the signature bytes */
    for(i=nRead-20; i>=0; i--){
      if( aRead[i]==0x50 && aRead[i+1]==0x4b 
       && aRead[i+2]==0x05 && aRead[i+3]==0x06 
      ){
        break;
      }
    }
    if( i<0 ){
      zipfileTableErr(pTab, "cannot find end of central directory record");
      return SQLITE_ERROR;
    }

    aRead += i+4;
    pEOCD->iDisk = zipfileRead16(aRead);
    pEOCD->iFirstDisk = zipfileRead16(aRead);
    pEOCD->nEntry = zipfileRead16(aRead);
    pEOCD->nEntryTotal = zipfileRead16(aRead);
    pEOCD->nSize = zipfileRead32(aRead);
    pEOCD->iOffset = zipfileRead32(aRead);
  }

  return rc;
}

/*
** Add object pNew to the linked list that begins at ZipfileTab.pFirstEntry 
** and ends with pLastEntry. If argument pBefore is NULL, then pNew is added
** to the end of the list. Otherwise, it is added to the list immediately
** before pBefore (which is guaranteed to be a part of said list).
*/
static void zipfileAddEntry(
  ZipfileTab *pTab, 
  ZipfileEntry *pBefore, 
  ZipfileEntry *pNew
){
  assert( (pTab->pFirstEntry==0)==(pTab->pLastEntry==0) );
  assert( pNew->pNext==0 );
  if( pBefore==0 ){
    if( pTab->pFirstEntry==0 ){
      pTab->pFirstEntry = pTab->pLastEntry = pNew;
    }else{
      assert( pTab->pLastEntry->pNext==0 );
      pTab->pLastEntry->pNext = pNew;
      pTab->pLastEntry = pNew;
    }
  }else{
    ZipfileEntry **pp;
    for(pp=&pTab->pFirstEntry; *pp!=pBefore; pp=&((*pp)->pNext));
    pNew->pNext = pBefore;
    *pp = pNew;
  }
}

static int zipfileLoadDirectory(ZipfileTab *pTab, const u8 *aBlob, i64 nBlob){
  ZipfileEOCD eocd;
  int rc;
  int i;
  i64 iOff;

  rc = zipfileReadEOCD(pTab, aBlob, nBlob, pTab->pWriteFd, &eocd);
  iOff = eocd.iOffset;
  for(i=0; rc==SQLITE_OK && i<eocd.nEntry; i++){
    ZipfileEntry *pNew = 0;
    rc = zipfileGetEntry(pTab, aBlob, nBlob, pTab->pWriteFd, iOff, &pNew);

    if( rc==SQLITE_OK ){
      zipfileAddEntry(pTab, 0, pNew);
      iOff += ZIPFILE_CDS_FIXED_SZ;
      iOff += (int)pNew->cds.nExtra + pNew->cds.nFile + pNew->cds.nComment;
    }
  }
  return rc;
}

/*
** xFilter callback.
*/
static int zipfileFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  ZipfileTab *pTab = (ZipfileTab*)cur->pVtab;
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  const char *zFile = 0;          /* Zip file to scan */
  int rc = SQLITE_OK;             /* Return Code */
  int bInMemory = 0;              /* True for an in-memory zipfile */

  (void)idxStr;
  (void)argc;

  zipfileResetCursor(pCsr);

  if( pTab->zFile ){
    zFile = pTab->zFile;
  }else if( idxNum==0 ){
    zipfileCursorErr(pCsr, "zipfile() function requires an argument");
    return SQLITE_ERROR;
  }else if( sqlite3_value_type(argv[0])==SQLITE_BLOB ){
    static const u8 aEmptyBlob = 0;
    const u8 *aBlob = (const u8*)sqlite3_value_blob(argv[0]);
    i64 nBlob = sqlite3_value_bytes(argv[0]);
    assert( pTab->pFirstEntry==0 );
    if( aBlob==0 ){
      aBlob = &aEmptyBlob;
      nBlob = 0;
    }
    rc = zipfileLoadDirectory(pTab, aBlob, nBlob);
    pCsr->pFreeEntry = pTab->pFirstEntry;
    pTab->pFirstEntry = pTab->pLastEntry = 0;
    if( rc!=SQLITE_OK ) return rc;
    bInMemory = 1;
  }else{
    zFile = (const char*)sqlite3_value_text(argv[0]);
  }

  if( 0==pTab->pWriteFd && 0==bInMemory ){
    pCsr->pFile = zFile ? sqlite3_fopen(zFile, "rb") : 0;
    if( pCsr->pFile==0 ){
      zipfileCursorErr(pCsr, "cannot open file: %s", zFile);
      rc = SQLITE_ERROR;
    }else{
      rc = zipfileReadEOCD(pTab, 0, 0, pCsr->pFile, &pCsr->eocd);
      if( rc==SQLITE_OK ){
        if( pCsr->eocd.nEntry==0 ){
          pCsr->bEof = 1;
        }else{
          pCsr->iNextOff = pCsr->eocd.iOffset;
          rc = zipfileNext(cur);
        }
      }
    }
  }else{
    pCsr->bNoop = 1;
    pCsr->pCurrent = pCsr->pFreeEntry ? pCsr->pFreeEntry : pTab->pFirstEntry;
    rc = zipfileNext(cur);
  }

  return rc;
}

/*
** xBestIndex callback.
*/
static int zipfileBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;
  int idx = -1;
  int unusable = 0;
  (void)tab;

  for(i=0; i<pIdxInfo->nConstraint; i++){
    const struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
    if( pCons->iColumn!=ZIPFILE_F_COLUMN_IDX ) continue;
    if( pCons->usable==0 ){
      unusable = 1;
    }else if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      idx = i;
    }
  }
  pIdxInfo->estimatedCost = 1000.0;
  if( idx>=0 ){
    pIdxInfo->aConstraintUsage[idx].argvIndex = 1;
    pIdxInfo->aConstraintUsage[idx].omit = 1;
    pIdxInfo->idxNum = 1;
  }else if( unusable ){
    return SQLITE_CONSTRAINT;
  }
  return SQLITE_OK;
}

static ZipfileEntry *zipfileNewEntry(const char *zPath){
  ZipfileEntry *pNew;
  pNew = sqlite3_malloc64(sizeof(ZipfileEntry));
  if( pNew ){
    memset(pNew, 0, sizeof(ZipfileEntry));
    pNew->cds.zFile = sqlite3_mprintf("%s", zPath);
    if( pNew->cds.zFile==0 ){
      sqlite3_free(pNew);
      pNew = 0;
    }
  }
  return pNew;
}

static int zipfileSerializeLFH(ZipfileEntry *pEntry, u8 *aBuf){
  ZipfileCDS *pCds = &pEntry->cds;
  u8 *a = aBuf;

  pCds->nExtra = 9;

  /* Write the LFH itself */
  zipfileWrite32(a, ZIPFILE_SIGNATURE_LFH);
  zipfileWrite16(a, pCds->iVersionExtract);
  zipfileWrite16(a, pCds->flags);
  zipfileWrite16(a, pCds->iCompression);
  zipfileWrite16(a, pCds->mTime);
  zipfileWrite16(a, pCds->mDate);
  zipfileWrite32(a, pCds->crc32);
  zipfileWrite32(a, pCds->szCompressed);
  zipfileWrite32(a, pCds->szUncompressed);
  zipfileWrite16(a, (u16)pCds->nFile);
  zipfileWrite16(a, pCds->nExtra);
  assert( a==&aBuf[ZIPFILE_LFH_FIXED_SZ] );

  /* Add the file name */
  memcpy(a, pCds->zFile, (int)pCds->nFile);
  a += (int)pCds->nFile;

  /* The "extra" data */
  zipfileWrite16(a, ZIPFILE_EXTRA_TIMESTAMP);
  zipfileWrite16(a, 5);
  *a++ = 0x01;
  zipfileWrite32(a, pEntry->mUnixTime);

  return a-aBuf;
}

static int zipfileAppendEntry(
  ZipfileTab *pTab,
  ZipfileEntry *pEntry,
  const u8 *pData,
  int nData
){
  u8 *aBuf = pTab->aBuffer;
  int nBuf;
  int rc;

  nBuf = zipfileSerializeLFH(pEntry, aBuf);
  rc = zipfileAppendData(pTab, aBuf, nBuf);
  if( rc==SQLITE_OK ){
    pEntry->iDataOff = pTab->szCurrent;
    rc = zipfileAppendData(pTab, pData, nData);
  }

  return rc;
}

static int zipfileGetMode(
  sqlite3_value *pVal, 
  int bIsDir,                     /* If true, default to directory */
  u32 *pMode,                     /* OUT: Mode value */
  char **pzErr                    /* OUT: Error message */
){
  const char *z = (const char*)sqlite3_value_text(pVal);
  u32 mode = 0;
  if( z==0 ){
    mode = (bIsDir ? (S_IFDIR + 0755) : (S_IFREG + 0644));
  }else if( z[0]>='0' && z[0]<='9' ){
    mode = (unsigned int)sqlite3_value_int(pVal);
  }else{
    const char zTemplate[11] = "-rwxrwxrwx";
    int i;
    if( strlen(z)!=10 ) goto parse_error;
    switch( z[0] ){
      case '-': mode |= S_IFREG; break;
      case 'd': mode |= S_IFDIR; break;
      case 'l': mode |= S_IFLNK; break;
      default: goto parse_error;
    }
    for(i=1; i<10; i++){
      if( z[i]==zTemplate[i] ) mode |= 1 << (9-i);
      else if( z[i]!='-' ) goto parse_error;
    }
  }
  if( ((mode & S_IFDIR)==0)==bIsDir ){
    /* The "mode" attribute is a directory, but data has been specified.
    ** Or vice-versa - no data but "mode" is a file or symlink.  */
    *pzErr = sqlite3_mprintf("zipfile: mode does not match data");
    return SQLITE_CONSTRAINT;
  }
  *pMode = mode;
  return SQLITE_OK;

 parse_error:
  *pzErr = sqlite3_mprintf("zipfile: parse error in mode: %s", z);
  return SQLITE_ERROR;
}

/*
** Both (const char*) arguments point to nul-terminated strings. Argument
** nB is the value of strlen(zB). This function returns 0 if the strings are
** identical, ignoring any trailing '/' character in either path.  */
static int zipfileComparePath(const char *zA, const char *zB, int nB){
  int nA = (int)strlen(zA);
  if( nA>0 && zA[nA-1]=='/' ) nA--;
  if( nB>0 && zB[nB-1]=='/' ) nB--;
  if( nA==nB && memcmp(zA, zB, nA)==0 ) return 0;
  return 1;
}

static int zipfileBegin(sqlite3_vtab *pVtab){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;

  assert( pTab->pWriteFd==0 );
  if( pTab->zFile==0 || pTab->zFile[0]==0 ){
    zipfileTableErr(pTab, "zipfile: missing filename");
    return SQLITE_ERROR;
  }

  /* Open a write fd on the file. Also load the entire central directory
  ** structure into memory. During the transaction any new file data is 
  ** appended to the archive file, but the central directory is accumulated
  ** in main-memory until the transaction is committed.  */
  pTab->pWriteFd = sqlite3_fopen(pTab->zFile, "ab+");
  if( pTab->pWriteFd==0 ){
    zipfileTableErr(pTab,
      "zipfile: failed to open file %s for writing", pTab->zFile
    );
    rc = SQLITE_ERROR;
  }else{
    fseek(pTab->pWriteFd, 0, SEEK_END);
    pTab->szCurrent = pTab->szOrig = (i64)ftell(pTab->pWriteFd);
    rc = zipfileLoadDirectory(pTab, 0, 0);
  }

  if( rc!=SQLITE_OK ){
    zipfileCleanupTransaction(pTab);
  }

  return rc;
}

/*
** Return the current time as a 32-bit timestamp in UNIX epoch format (like
** time(2)).
*/
static u32 zipfileTime(void){
  sqlite3_vfs *pVfs = sqlite3_vfs_find(0);
  u32 ret;
  if( pVfs==0 ) return 0;
  if( pVfs->iVersion>=2 && pVfs->xCurrentTimeInt64 ){
    i64 ms;
    pVfs->xCurrentTimeInt64(pVfs, &ms);
    ret = (u32)((ms/1000) - ((i64)24405875 * 8640));
  }else{
    double day;
    pVfs->xCurrentTime(pVfs, &day);
    ret = (u32)((day - 2440587.5) * 86400);
  }
  return ret;
}

/*
** Return a 32-bit timestamp in UNIX epoch format.
**
** If the value passed as the only argument is either NULL or an SQL NULL,
** return the current time. Otherwise, return the value stored in (*pVal)
** cast to a 32-bit unsigned integer.
*/
static u32 zipfileGetTime(sqlite3_value *pVal){
  if( pVal==0 || sqlite3_value_type(pVal)==SQLITE_NULL ){
    return zipfileTime();
  }
  return (u32)sqlite3_value_int64(pVal);
}

/*
** Unless it is NULL, entry pOld is currently part of the pTab->pFirstEntry
** linked list.  Remove it from the list and free the object.
*/
static void zipfileRemoveEntryFromList(ZipfileTab *pTab, ZipfileEntry *pOld){
  if( pOld ){
    if( pTab->pFirstEntry==pOld ){
      pTab->pFirstEntry = pOld->pNext;
      if( pTab->pLastEntry==pOld ) pTab->pLastEntry = 0;
    }else{
      ZipfileEntry *p;
      for(p=pTab->pFirstEntry; p; p=p->pNext){
        if( p->pNext==pOld ){
          p->pNext = pOld->pNext;
          if( pTab->pLastEntry==pOld ) pTab->pLastEntry = p;
          break;
        }
      }
    }
    zipfileEntryFree(pOld);
  }
}

/*
** xUpdate method.
*/
static int zipfileUpdate(
  sqlite3_vtab *pVtab, 
  int nVal, 
  sqlite3_value **apVal, 
  sqlite_int64 *pRowid
){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  ZipfileEntry *pNew = 0;         /* New in-memory CDS entry */

  u32 mode = 0;                   /* Mode for new entry */
  u32 mTime = 0;                  /* Modification time for new entry */
  i64 sz = 0;                     /* Uncompressed size */
  const char *zPath = 0;          /* Path for new entry */
  int nPath = 0;                  /* strlen(zPath) */
  const u8 *pData = 0;            /* Pointer to buffer containing content */
  size_t nData = 0;               /* Size of pData buffer in bytes */
  int iMethod = 0;                /* Compression method for new entry */
  u8 *pFree = 0;                  /* Free this */
  char *zFree = 0;                /* Also free this */
  ZipfileEntry *pOld = 0;
  ZipfileEntry *pOld2 = 0;
  int bUpdate = 0;                /* True for an update that modifies "name" */
  int bIsDir = 0;
  u32 iCrc32 = 0;

  (void)pRowid;

  if( pTab->pWriteFd==0 ){
    rc = zipfileBegin(pVtab);
    if( rc!=SQLITE_OK ) return rc;
  }

  /* If this is a DELETE or UPDATE, find the archive entry to delete. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    const char *zDelete = (const char*)sqlite3_value_text(apVal[0]);
    int nDelete = (int)strlen(zDelete);
    if( nVal>1 ){
      const char *zUpdate = (const char*)sqlite3_value_text(apVal[1]);
      if( zUpdate && zipfileComparePath(zUpdate, zDelete, nDelete)!=0 ){
        bUpdate = 1;
      }
    }
    for(pOld=pTab->pFirstEntry; 1; pOld=pOld->pNext){
      if( zipfileComparePath(pOld->cds.zFile, zDelete, nDelete)==0 ){
        break;
      }
      assert( pOld->pNext );
    }
  }

  if( nVal>1 ){
    /* Check that "sz" and "rawdata" are both NULL: */
    if( sqlite3_value_type(apVal[5])!=SQLITE_NULL ){
      zipfileTableErr(pTab, "sz must be NULL");
      rc = SQLITE_CONSTRAINT;
    }
    if( sqlite3_value_type(apVal[6])!=SQLITE_NULL ){
      zipfileTableErr(pTab, "rawdata must be NULL"); 
      rc = SQLITE_CONSTRAINT;
    }

    if( rc==SQLITE_OK ){
      if( sqlite3_value_type(apVal[7])==SQLITE_NULL ){
        /* data=NULL. A directory */
        bIsDir = 1;
      }else{
        /* Value specified for "data", and possibly "method". This must be
        ** a regular file or a symlink. */
        const u8 *aIn = sqlite3_value_blob(apVal[7]);
        size_t nIn = sqlite3_value_bytes(apVal[7]);
        int bAuto = sqlite3_value_type(apVal[8])==SQLITE_NULL;

        iMethod = sqlite3_value_int(apVal[8]);
        sz = nIn;
        pData = aIn;
        nData = nIn;
        if( iMethod!=0 && iMethod!=8 ){
          zipfileTableErr(pTab, "unknown compression method: %d", iMethod);
          rc = SQLITE_CONSTRAINT;
        }else{
          if( bAuto || iMethod ){
            size_t nCmp;
            rc = zipfileDeflate(aIn, nIn, &pFree, &nCmp, &pTab->base.zErrMsg);
            if( rc==SQLITE_OK ){
              if( iMethod || nCmp<nIn ){
                iMethod = 8;
                pData = pFree;
                nData = nCmp;
              }
            }
          }
          iCrc32 = crc32(0, aIn, nIn);
        }
      }
    }

    if( rc==SQLITE_OK ){
      rc = zipfileGetMode(apVal[3], bIsDir, &mode, &pTab->base.zErrMsg);
    }

    if( rc==SQLITE_OK ){
      zPath = (const char*)sqlite3_value_text(apVal[2]);
      if( zPath==0 ) zPath = "";
      nPath = (int)strlen(zPath);
      if( nPath>ZIPFILE_MX_NAME ){
        zipfileTableErr(pTab, "filename too long; max: %d bytes",
                        ZIPFILE_MX_NAME);
        rc = SQLITE_CONSTRAINT;
      }
      mTime = zipfileGetTime(apVal[4]);
    }

    if( rc==SQLITE_OK && bIsDir ){
      /* For a directory, check that the last character in the path is a
      ** '/'. This appears to be required for compatibility with info-zip
      ** (the unzip command on unix). It does not create directories
      ** otherwise.  */
      if( nPath<=0 || zPath[nPath-1]!='/' ){
        zFree = sqlite3_mprintf("%s/", zPath);
        zPath = (const char*)zFree;
        if( zFree==0 ){
          rc = SQLITE_NOMEM;
          nPath = 0;
        }else{
          nPath = (int)strlen(zPath);
        }
      }
    }

    /* Check that we're not inserting a duplicate entry -OR- updating an
    ** entry with a path, thereby making it into a duplicate. */
    if( (pOld==0 || bUpdate) && rc==SQLITE_OK ){
      ZipfileEntry *p;
      for(p=pTab->pFirstEntry; p; p=p->pNext){
        if( zipfileComparePath(p->cds.zFile, zPath, nPath)==0 ){
          switch( sqlite3_vtab_on_conflict(pTab->db) ){
            case SQLITE_IGNORE: {
              goto zipfile_update_done;
            }
            case SQLITE_REPLACE: {
              pOld2 = p;
              break;
            }
            default: {
              zipfileTableErr(pTab, "duplicate name: \"%s\"", zPath);
              rc = SQLITE_CONSTRAINT;
              break;
            }
          }
          break;
        }
      }
    }

    if( rc==SQLITE_OK ){
      /* Create the new CDS record. */
      pNew = zipfileNewEntry(zPath);
      if( pNew==0 ){
        rc = SQLITE_NOMEM;
      }else{
        pNew->cds.iVersionMadeBy = ZIPFILE_NEWENTRY_MADEBY;
        pNew->cds.iVersionExtract = ZIPFILE_NEWENTRY_REQUIRED;
        pNew->cds.flags = ZIPFILE_NEWENTRY_FLAGS;
        pNew->cds.iCompression = (u16)iMethod;
        zipfileMtimeToDos(&pNew->cds, mTime);
        pNew->cds.crc32 = iCrc32;
        pNew->cds.szCompressed = nData;
        pNew->cds.szUncompressed = (u32)sz;
        pNew->cds.iExternalAttr = (mode<<16);
        pNew->cds.iOffset = (u32)pTab->szCurrent;
        pNew->cds.nFile = (u16)nPath;
        pNew->mUnixTime = (u32)mTime;
        rc = zipfileAppendEntry(pTab, pNew, pData, nData);
        zipfileAddEntry(pTab, pOld, pNew);
      }
    }
  }

  if( rc==SQLITE_OK && (pOld || pOld2) ){
    ZipfileCsr *pCsr;
    for(pCsr=pTab->pCsrList; pCsr; pCsr=pCsr->pCsrNext){
      if( pCsr->pCurrent && (pCsr->pCurrent==pOld || pCsr->pCurrent==pOld2) ){
        pCsr->pCurrent = pCsr->pCurrent->pNext;
        pCsr->bNoop = 1;
      }
    }

    zipfileRemoveEntryFromList(pTab, pOld);
    zipfileRemoveEntryFromList(pTab, pOld2);
  }

zipfile_update_done:
  sqlite3_free(pFree);
  sqlite3_free(zFree);
  return rc;
}

static int zipfileSerializeEOCD(ZipfileEOCD *p, u8 *aBuf){
  u8 *a = aBuf;
  zipfileWrite32(a, ZIPFILE_SIGNATURE_EOCD);
  zipfileWrite16(a, p->iDisk);
  zipfileWrite16(a, p->iFirstDisk);
  zipfileWrite16(a, p->nEntry);
  zipfileWrite16(a, p->nEntryTotal);
  zipfileWrite32(a, p->nSize);
  zipfileWrite32(a, p->iOffset);
  zipfileWrite16(a, 0);        /* Size of trailing comment in bytes*/

  return a-aBuf;
}

static int zipfileAppendEOCD(ZipfileTab *pTab, ZipfileEOCD *p){
  int nBuf = zipfileSerializeEOCD(p, pTab->aBuffer);
  assert( nBuf==ZIPFILE_EOCD_FIXED_SZ );
  return zipfileAppendData(pTab, pTab->aBuffer, nBuf);
}

/*
** Serialize the CDS structure into buffer aBuf[]. Return the number
** of bytes written.
*/
static int zipfileSerializeCDS(ZipfileEntry *pEntry, u8 *aBuf){
  u8 *a = aBuf;
  ZipfileCDS *pCDS = &pEntry->cds;

  if( pEntry->aExtra==0 ){
    pCDS->nExtra = 9;
  }

  zipfileWrite32(a, ZIPFILE_SIGNATURE_CDS);
  zipfileWrite16(a, pCDS->iVersionMadeBy);
  zipfileWrite16(a, pCDS->iVersionExtract);
  zipfileWrite16(a, pCDS->flags);
  zipfileWrite16(a, pCDS->iCompression);
  zipfileWrite16(a, pCDS->mTime);
  zipfileWrite16(a, pCDS->mDate);
  zipfileWrite32(a, pCDS->crc32);
  zipfileWrite32(a, pCDS->szCompressed);
  zipfileWrite32(a, pCDS->szUncompressed);
  assert( a==&aBuf[ZIPFILE_CDS_NFILE_OFF] );
  zipfileWrite16(a, pCDS->nFile);
  zipfileWrite16(a, pCDS->nExtra);
  zipfileWrite16(a, pCDS->nComment);
  zipfileWrite16(a, pCDS->iDiskStart);
  zipfileWrite16(a, pCDS->iInternalAttr);
  zipfileWrite32(a, pCDS->iExternalAttr);
  zipfileWrite32(a, pCDS->iOffset);

  memcpy(a, pCDS->zFile, pCDS->nFile);
  a += pCDS->nFile;

  if( pEntry->aExtra ){
    int n = (int)pCDS->nExtra + (int)pCDS->nComment;
    memcpy(a, pEntry->aExtra, n);
    a += n;
  }else{
    assert( pCDS->nExtra==9 );
    zipfileWrite16(a, ZIPFILE_EXTRA_TIMESTAMP);
    zipfileWrite16(a, 5);
    *a++ = 0x01;
    zipfileWrite32(a, pEntry->mUnixTime);
  }

  return a-aBuf;
}

static int zipfileCommit(sqlite3_vtab *pVtab){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;
  if( pTab->pWriteFd ){
    i64 iOffset = pTab->szCurrent;
    ZipfileEntry *p;
    ZipfileEOCD eocd;
    int nEntry = 0;

    /* Write out all entries */
    for(p=pTab->pFirstEntry; rc==SQLITE_OK && p; p=p->pNext){
      int n = zipfileSerializeCDS(p, pTab->aBuffer);
      rc = zipfileAppendData(pTab, pTab->aBuffer, n);
      nEntry++;
    }

    /* Write out the EOCD record */
    eocd.iDisk = 0;
    eocd.iFirstDisk = 0;
    eocd.nEntry = (u16)nEntry;
    eocd.nEntryTotal = (u16)nEntry;
    eocd.nSize = (u32)(pTab->szCurrent - iOffset);
    eocd.iOffset = (u32)iOffset;
    rc = zipfileAppendEOCD(pTab, &eocd);

    zipfileCleanupTransaction(pTab);
  }
  return rc;
}

static int zipfileRollback(sqlite3_vtab *pVtab){
  return zipfileCommit(pVtab);
}

static ZipfileCsr *zipfileFindCursor(ZipfileTab *pTab, i64 iId){
  ZipfileCsr *pCsr;
  for(pCsr=pTab->pCsrList; pCsr; pCsr=pCsr->pCsrNext){
    if( iId==pCsr->iId ) break;
  }
  return pCsr;
}

static void zipfileFunctionCds(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  ZipfileCsr *pCsr;
  ZipfileTab *pTab = (ZipfileTab*)sqlite3_user_data(context);
  assert( argc>0 );

  pCsr = zipfileFindCursor(pTab, sqlite3_value_int64(argv[0]));
  if( pCsr ){
    ZipfileCDS *p = &pCsr->pCurrent->cds;
    char *zRes = sqlite3_mprintf("{"
        "\"version-made-by\" : %u, "
        "\"version-to-extract\" : %u, "
        "\"flags\" : %u, "
        "\"compression\" : %u, "
        "\"time\" : %u, "
        "\"date\" : %u, "
        "\"crc32\" : %u, "
        "\"compressed-size\" : %u, "
        "\"uncompressed-size\" : %u, "
        "\"file-name-length\" : %u, "
        "\"extra-field-length\" : %u, "
        "\"file-comment-length\" : %u, "
        "\"disk-number-start\" : %u, "
        "\"internal-attr\" : %u, "
        "\"external-attr\" : %u, "
        "\"offset\" : %u }",
        (u32)p->iVersionMadeBy, (u32)p->iVersionExtract,
        (u32)p->flags, (u32)p->iCompression,
        (u32)p->mTime, (u32)p->mDate,
        (u32)p->crc32, (u32)p->szCompressed,
        (u32)p->szUncompressed, (u32)p->nFile,
        (u32)p->nExtra, (u32)p->nComment,
        (u32)p->iDiskStart, (u32)p->iInternalAttr,
        (u32)p->iExternalAttr, (u32)p->iOffset
    );

    if( zRes==0 ){
      sqlite3_result_error_nomem(context);
    }else{
      sqlite3_result_text(context, zRes, -1, SQLITE_TRANSIENT);
      sqlite3_free(zRes);
    }
  }
}

/*
** xFindFunction method.
*/
static int zipfileFindFunction(
  sqlite3_vtab *pVtab,            /* Virtual table handle */
  int nArg,                       /* Number of SQL function arguments */
  const char *zName,              /* Name of SQL function */
  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */
  void **ppArg                    /* OUT: User data for *pxFunc */
){
  (void)nArg;
  if( sqlite3_stricmp("zipfile_cds", zName)==0 ){
    *pxFunc = zipfileFunctionCds;
    *ppArg = (void*)pVtab;
    return 1;
  }
  return 0;
}

typedef struct ZipfileBuffer ZipfileBuffer;
struct ZipfileBuffer {
  u8 *a;                          /* Pointer to buffer */
  size_t n;                       /* Size of buffer in bytes */
  size_t nAlloc;                  /* Byte allocated at a[] */
};

typedef struct ZipfileCtx ZipfileCtx;
struct ZipfileCtx {
  int nEntry;
  ZipfileBuffer body;
  ZipfileBuffer cds;
};

static int zipfileBufferGrow(ZipfileBuffer *pBuf, size_t nByte){
  if( pBuf->n+nByte>pBuf->nAlloc ){
    u8 *aNew;
    size_t nNew = pBuf->n ? pBuf->n*2 : 512;
    size_t nReq = pBuf->n + nByte;

    while( nNew<nReq ) nNew = nNew*2;
    aNew = sqlite3_realloc(pBuf->a, nNew);
    if( aNew==0 ) return SQLITE_NOMEM;
    pBuf->a = aNew;
    pBuf->nAlloc = (int)nNew;
  }
  return SQLITE_OK;
}

/*
** xStep() callback for the zipfile() aggregate. This can be called in
** any of the following ways:
**
**   SELECT zipfile(name,data) ...
**   SELECT zipfile(name,mode,mtime,data) ...
**   SELECT zipfile(name,mode,mtime,data,method) ...
*/
static void zipfileStep(sqlite3_context *pCtx, int nVal, sqlite3_value **apVal){
  ZipfileCtx *p;                  /* Aggregate function context */
  ZipfileEntry e;                 /* New entry to add to zip archive */

  sqlite3_value *pName = 0;
  sqlite3_value *pMode = 0;
  sqlite3_value *pMtime = 0;
  sqlite3_value *pData = 0;
  sqlite3_value *pMethod = 0;

  int bIsDir = 0;
  u32 mode;
  int rc = SQLITE_OK;
  char *zErr = 0;

  int iMethod = -1;               /* Compression method to use (0 or 8) */

  const u8 *aData = 0;            /* Possibly compressed data for new entry */
  size_t nData = 0;               /* Size of aData[] in bytes */
  int szUncompressed = 0;         /* Size of data before compression */
  u8 *aFree = 0;                  /* Free this before returning */
  u32 iCrc32 = 0;                 /* crc32 of uncompressed data */

  char *zName = 0;                /* Path (name) of new entry */
  int nName = 0;                  /* Size of zName in bytes */
  char *zFree = 0;                /* Free this before returning */
  size_t nByte;

  memset(&e, 0, sizeof(e));
  p = (ZipfileCtx*)sqlite3_aggregate_context(pCtx, sizeof(ZipfileCtx));
  if( p==0 ) return;

  /* Martial the arguments into stack variables */
  if( nVal!=2 && nVal!=4 && nVal!=5 ){
    zErr = sqlite3_mprintf("wrong number of arguments to function zipfile()");
    rc = SQLITE_ERROR;
    goto zipfile_step_out;
  }
  pName = apVal[0];
  if( nVal==2 ){
    pData = apVal[1];
  }else{
    pMode = apVal[1];
    pMtime = apVal[2];
    pData = apVal[3];
    if( nVal==5 ){
      pMethod = apVal[4];
    }
  }

  /* Check that the 'name' parameter looks ok. */
  zName = (char*)sqlite3_value_text(pName);
  nName = sqlite3_value_bytes(pName);
  if( zName==0 ){
    zErr = sqlite3_mprintf("first argument to zipfile() must be non-NULL");
    rc = SQLITE_ERROR;
    goto zipfile_step_out;
  }
  if( nName>ZIPFILE_MX_NAME ){
    zErr = sqlite3_mprintf(
               "filename argument to zipfile() too big; max: %d bytes",
               ZIPFILE_MX_NAME);
    rc = SQLITE_ERROR;
    goto zipfile_step_out;
  }

  /* Inspect the 'method' parameter. This must be either 0 (store), 8 (use
  ** deflate compression) or NULL (choose automatically).  */
  if( pMethod && SQLITE_NULL!=sqlite3_value_type(pMethod) ){
    iMethod = (int)sqlite3_value_int64(pMethod);
    if( iMethod!=0 && iMethod!=8 ){
      zErr = sqlite3_mprintf("illegal method value: %d", iMethod);
      rc = SQLITE_ERROR;
      goto zipfile_step_out;
    }
  }

  /* Now inspect the data. If this is NULL, then the new entry must be a
  ** directory.  Otherwise, figure out whether or not the data should
  ** be deflated or simply stored in the zip archive. */
  if( sqlite3_value_type(pData)==SQLITE_NULL ){
    bIsDir = 1;
    iMethod = 0;
  }else{
    aData = sqlite3_value_blob(pData);
    szUncompressed = nData = sqlite3_value_bytes(pData);
    iCrc32 = crc32(0, aData, nData);
    if( iMethod<0 || iMethod==8 ){
      size_t nOut = 0;
      rc = zipfileDeflate(aData, nData, &aFree, &nOut, &zErr);
      if( rc!=SQLITE_OK ){
        goto zipfile_step_out;
      }
      if( iMethod==8 || nOut<nData ){
        aData = aFree;
        nData = nOut;
        iMethod = 8;
      }else{
        iMethod = 0;
      }
    }
  }

  /* Decode the "mode" argument. */
  rc = zipfileGetMode(pMode, bIsDir, &mode, &zErr);
  if( rc ) goto zipfile_step_out;

  /* Decode the "mtime" argument. */
  e.mUnixTime = zipfileGetTime(pMtime);

  /* If this is a directory entry, ensure that there is exactly one '/'
  ** at the end of the path. Or, if this is not a directory and the path
  ** ends in '/' it is an error. */
  if( bIsDir==0 ){
    if( nName>0 && zName[nName-1]=='/' ){
      zErr = sqlite3_mprintf("non-directory name must not end with /");
      rc = SQLITE_ERROR;
      goto zipfile_step_out;
    }
  }else{
    if( nName==0 || zName[nName-1]!='/' ){
      zName = zFree = sqlite3_mprintf("%s/", zName);
      if( zName==0 ){
        rc = SQLITE_NOMEM;
        goto zipfile_step_out;
      }
      nName = (int)strlen(zName);
    }else{
      while( nName>1 && zName[nName-2]=='/' ) nName--;
    }
  }

  /* Assemble the ZipfileEntry object for the new zip archive entry */
  e.cds.iVersionMadeBy = ZIPFILE_NEWENTRY_MADEBY;
  e.cds.iVersionExtract = ZIPFILE_NEWENTRY_REQUIRED;
  e.cds.flags = ZIPFILE_NEWENTRY_FLAGS;
  e.cds.iCompression = (u16)iMethod;
  zipfileMtimeToDos(&e.cds, (u32)e.mUnixTime);
  e.cds.crc32 = iCrc32;
  e.cds.szCompressed = nData;
  e.cds.szUncompressed = szUncompressed;
  e.cds.iExternalAttr = (mode<<16);
  e.cds.iOffset = p->body.n;
  e.cds.nFile = (u16)nName;
  e.cds.zFile = zName;

  /* Append the LFH to the body of the new archive */
  nByte = ZIPFILE_LFH_FIXED_SZ + e.cds.nFile + 9;
  if( (rc = zipfileBufferGrow(&p->body, nByte)) ) goto zipfile_step_out;
  p->body.n += zipfileSerializeLFH(&e, &p->body.a[p->body.n]);

  /* Append the data to the body of the new archive */
  if( nData>0 ){
    if( (rc = zipfileBufferGrow(&p->body, nData)) ) goto zipfile_step_out;
    memcpy(&p->body.a[p->body.n], aData, nData);
    p->body.n += nData;
  }

  /* Append the CDS record to the directory of the new archive */
  nByte = ZIPFILE_CDS_FIXED_SZ + e.cds.nFile + 9;
  if( (rc = zipfileBufferGrow(&p->cds, nByte)) ) goto zipfile_step_out;
  p->cds.n += zipfileSerializeCDS(&e, &p->cds.a[p->cds.n]);

  /* Increment the count of entries in the archive */
  p->nEntry++;

 zipfile_step_out:
  sqlite3_free(aFree);
  sqlite3_free(zFree);
  if( rc ){
    if( zErr ){
      sqlite3_result_error(pCtx, zErr, -1);
    }else{
      sqlite3_result_error_code(pCtx, rc);
    }
  }
  sqlite3_free(zErr);
}

/*
** xFinalize() callback for zipfile aggregate function.
*/
static void zipfileFinal(sqlite3_context *pCtx){
  ZipfileCtx *p;
  ZipfileEOCD eocd;
  size_t nZip;
  u8 *aZip;

  p = (ZipfileCtx*)sqlite3_aggregate_context(pCtx, sizeof(ZipfileCtx));
  if( p==0 ) return;
  if( p->nEntry>0 ){
    memset(&eocd, 0, sizeof(eocd));
    eocd.nEntry = (u16)p->nEntry;
    eocd.nEntryTotal = (u16)p->nEntry;
    eocd.nSize = p->cds.n;
    eocd.iOffset = p->body.n;

    nZip = p->body.n + p->cds.n + ZIPFILE_EOCD_FIXED_SZ;
    aZip = (u8*)sqlite3_malloc(nZip);
    if( aZip==0 ){
      sqlite3_result_error_nomem(pCtx);
    }else{
      memcpy(aZip, p->body.a, p->body.n);
      memcpy(&aZip[p->body.n], p->cds.a, p->cds.n);
      zipfileSerializeEOCD(&eocd, &aZip[p->body.n + p->cds.n]);
      sqlite3_result_blob(pCtx, aZip, nZip, zipfileFree);
    }
  }

  sqlite3_free(p->body.a);
  sqlite3_free(p->cds.a);
}


/*
** Register the "zipfile" virtual table.
*/
static int zipfileRegister(sqlite3 *db){
  static const sqlite3_module zipfileModule = {
    1,                         /* iVersion */
    zipfileConnect,            /* xCreate */
    zipfileConnect,            /* xConnect */
    zipfileBestIndex,          /* xBestIndex */
    zipfileDisconnect,         /* xDisconnect */
    zipfileDisconnect,         /* xDestroy */
    zipfileOpen,               /* xOpen - open a cursor */
    zipfileClose,              /* xClose - close a cursor */
    zipfileFilter,             /* xFilter - configure scan constraints */
    zipfileNext,               /* xNext - advance a cursor */
    zipfileEof,                /* xEof - check for end of scan */
    zipfileColumn,             /* xColumn - read data */
    0,                         /* xRowid - read data */
    zipfileUpdate,             /* xUpdate */
    zipfileBegin,              /* xBegin */
    0,                         /* xSync */
    zipfileCommit,             /* xCommit */
    zipfileRollback,           /* xRollback */
    zipfileFindFunction,       /* xFindMethod */
    0,                         /* xRename */
    0,                         /* xSavepoint */
    0,                         /* xRelease */
    0,                         /* xRollback */
    0,                         /* xShadowName */
    0                          /* xIntegrity */
  };

  int rc = sqlite3_create_module(db, "zipfile"  , &zipfileModule, 0);
  if( rc==SQLITE_OK ) rc = sqlite3_overload_function(db, "zipfile_cds", -1);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "zipfile", -1, SQLITE_UTF8, 0, 0, 
        zipfileStep, zipfileFinal
    );
  }
  assert( sizeof(i64)==8 );
  assert( sizeof(u32)==4 );
  assert( sizeof(u16)==2 );
  assert( sizeof(u8)==1 );
  return rc;
}
#else         /* SQLITE_OMIT_VIRTUALTABLE */
# define zipfileRegister(x) SQLITE_OK
#endif

#ifdef _WIN32

#endif
int sqlite3_zipfile_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  return zipfileRegister(db);
}

/************************* End ext/misc/zipfile.c ********************/
/************************* Begin ext/misc/sqlar.c ******************/
/*
** 2017-12-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** Utility functions sqlar_compress() and sqlar_uncompress(). Useful
** for working with sqlar archives and used by the shell tool's built-in
** sqlar support.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <zlib.h>
#include <assert.h>

/*
** Implementation of the "sqlar_compress(X)" SQL function.
**
** If the type of X is SQLITE_BLOB, and compressing that blob using
** zlib utility function compress() yields a smaller blob, return the
** compressed blob. Otherwise, return a copy of X.
**
** SQLar uses the "zlib format" for compressed content.  The zlib format
** contains a two-byte identification header and a four-byte checksum at
** the end.  This is different from ZIP which uses the raw deflate format.
**
** Future enhancements to SQLar might add support for new compression formats.
** If so, those new formats will be identified by alternative headers in the
** compressed data.
*/
static void sqlarCompressFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  assert( argc==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB ){
    const Bytef *pData = sqlite3_value_blob(argv[0]);
    uLong nData = sqlite3_value_bytes(argv[0]);
    uLongf nOut = compressBound(nData);
    Bytef *pOut;

    pOut = (Bytef*)sqlite3_malloc64(nOut);
    if( pOut==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }else{
      if( Z_OK!=compress(pOut, &nOut, pData, nData) ){
        sqlite3_result_error(context, "error in compress()", -1);
      }else if( nOut<nData ){
        sqlite3_result_blob(context, pOut, nOut, SQLITE_TRANSIENT);
      }else{
        sqlite3_result_value(context, argv[0]);
      }
      sqlite3_free(pOut);
    }
  }else{
    sqlite3_result_value(context, argv[0]);
  }
}

/*
** Implementation of the "sqlar_uncompress(X,SZ)" SQL function
**
** Parameter SZ is interpreted as an integer. If it is less than or
** equal to zero, then this function returns a copy of X. Or, if
** SZ is equal to the size of X when interpreted as a blob, also
** return a copy of X. Otherwise, decompress blob X using zlib
** utility function uncompress() and return the results (another
** blob).
*/
static void sqlarUncompressFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  uLong nData;
  sqlite3_int64 sz;

  assert( argc==2 );
  sz = sqlite3_value_int64(argv[1]);

  if( sz<=0 || sz==(nData = sqlite3_value_bytes(argv[0])) ){
    sqlite3_result_value(context, argv[0]);
  }else{
    uLongf szf = sz;
    const Bytef *pData= sqlite3_value_blob(argv[0]);
    Bytef *pOut = sqlite3_malloc64(sz);
    if( pOut==0 ){
      sqlite3_result_error_nomem(context);
    }else if( Z_OK!=uncompress(pOut, &szf, pData, nData) ){
      sqlite3_result_error(context, "error in uncompress()", -1);
    }else{
      sqlite3_result_blob(context, pOut, szf, SQLITE_TRANSIENT);
    }
    sqlite3_free(pOut);
  }
}

#ifdef _WIN32

#endif
int sqlite3_sqlar_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sqlar_compress", 1, 
                               SQLITE_UTF8|SQLITE_INNOCUOUS, 0,
                               sqlarCompressFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sqlar_uncompress", 2,
                                 SQLITE_UTF8|SQLITE_INNOCUOUS, 0,
                                 sqlarUncompressFunc, 0, 0);
  }
  return rc;
}

/************************* End ext/misc/sqlar.c ********************/
#endif
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
/************************* Begin ext/expert/sqlite3expert.h ******************/
/*
** 2017 April 07
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/
#if !defined(SQLITEEXPERT_H)
#define SQLITEEXPERT_H 1
/* #include "sqlite3.h" */

typedef struct sqlite3expert sqlite3expert;

/*
** Create a new sqlite3expert object.
**
** If successful, a pointer to the new object is returned and (*pzErr) set
** to NULL. Or, if an error occurs, NULL is returned and (*pzErr) set to
** an English-language error message. In this case it is the responsibility
** of the caller to eventually free the error message buffer using
** sqlite3_free().
*/
sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErr);

/*
** Configure an sqlite3expert object.
**
** EXPERT_CONFIG_SAMPLE:
**   By default, sqlite3_expert_analyze() generates sqlite_stat1 data for
**   each candidate index. This involves scanning and sorting the entire
**   contents of each user database table once for each candidate index
**   associated with the table. For large databases, this can be 
**   prohibitively slow. This option allows the sqlite3expert object to
**   be configured so that sqlite_stat1 data is instead generated based on a
**   subset of each table, or so that no sqlite_stat1 data is used at all.
**
**   A single integer argument is passed to this option. If the value is less
**   than or equal to zero, then no sqlite_stat1 data is generated or used by
**   the analysis - indexes are recommended based on the database schema only.
**   Or, if the value is 100 or greater, complete sqlite_stat1 data is
**   generated for each candidate index (this is the default). Finally, if the
**   value falls between 0 and 100, then it represents the percentage of user
**   table rows that should be considered when generating sqlite_stat1 data.
**
**   Examples:
**
**     // Do not generate any sqlite_stat1 data
**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 0);
**
**     // Generate sqlite_stat1 data based on 10% of the rows in each table.
**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 10);
*/
int sqlite3_expert_config(sqlite3expert *p, int op, ...);

#define EXPERT_CONFIG_SAMPLE 1    /* int */

/*
** Specify zero or more SQL statements to be included in the analysis.
**
** Buffer zSql must contain zero or more complete SQL statements. This
** function parses all statements contained in the buffer and adds them
** to the internal list of statements to analyze. If successful, SQLITE_OK
** is returned and (*pzErr) set to NULL. Or, if an error occurs - for example
** due to a error in the SQL - an SQLite error code is returned and (*pzErr)
** may be set to point to an English language error message. In this case
** the caller is responsible for eventually freeing the error message buffer
** using sqlite3_free().
**
** If an error does occur while processing one of the statements in the
** buffer passed as the second argument, none of the statements in the
** buffer are added to the analysis.
**
** This function must be called before sqlite3_expert_analyze(). If a call
** to this function is made on an sqlite3expert object that has already
** been passed to sqlite3_expert_analyze() SQLITE_MISUSE is returned
** immediately and no statements are added to the analysis.
*/
int sqlite3_expert_sql(
  sqlite3expert *p,               /* From a successful sqlite3_expert_new() */
  const char *zSql,               /* SQL statement(s) to add */
  char **pzErr                    /* OUT: Error message (if any) */
);


/*
** This function is called after the sqlite3expert object has been configured
** with all SQL statements using sqlite3_expert_sql() to actually perform
** the analysis. Once this function has been called, it is not possible to
** add further SQL statements to the analysis.
**
** If successful, SQLITE_OK is returned and (*pzErr) is set to NULL. Or, if
** an error occurs, an SQLite error code is returned and (*pzErr) set to 
** point to a buffer containing an English language error message. In this
** case it is the responsibility of the caller to eventually free the buffer
** using sqlite3_free().
**
** If an error does occur within this function, the sqlite3expert object
** is no longer useful for any purpose. At that point it is no longer
** possible to add further SQL statements to the object or to re-attempt
** the analysis. The sqlite3expert object must still be freed using a call
** sqlite3_expert_destroy().
*/
int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr);

/*
** Return the total number of statements loaded using sqlite3_expert_sql().
** The total number of SQL statements may be different from the total number
** to calls to sqlite3_expert_sql().
*/
int sqlite3_expert_count(sqlite3expert*);

/*
** Return a component of the report.
**
** This function is called after sqlite3_expert_analyze() to extract the
** results of the analysis. Each call to this function returns either a
** NULL pointer or a pointer to a buffer containing a nul-terminated string.
** The value passed as the third argument must be one of the EXPERT_REPORT_*
** #define constants defined below.
**
** For some EXPERT_REPORT_* parameters, the buffer returned contains 
** information relating to a specific SQL statement. In these cases that
** SQL statement is identified by the value passed as the second argument.
** SQL statements are numbered from 0 in the order in which they are parsed.
** If an out-of-range value (less than zero or equal to or greater than the
** value returned by sqlite3_expert_count()) is passed as the second argument
** along with such an EXPERT_REPORT_* parameter, NULL is always returned.
**
** EXPERT_REPORT_SQL:
**   Return the text of SQL statement iStmt.
**
** EXPERT_REPORT_INDEXES:
**   Return a buffer containing the CREATE INDEX statements for all recommended
**   indexes for statement iStmt. If there are no new recommeded indexes, NULL 
**   is returned.
**
** EXPERT_REPORT_PLAN:
**   Return a buffer containing the EXPLAIN QUERY PLAN output for SQL query
**   iStmt after the proposed indexes have been added to the database schema.
**
** EXPERT_REPORT_CANDIDATES:
**   Return a pointer to a buffer containing the CREATE INDEX statements 
**   for all indexes that were tested (for all SQL statements). The iStmt
**   parameter is ignored for EXPERT_REPORT_CANDIDATES calls.
*/
const char *sqlite3_expert_report(sqlite3expert*, int iStmt, int eReport);

/*
** Values for the third argument passed to sqlite3_expert_report().
*/
#define EXPERT_REPORT_SQL        1
#define EXPERT_REPORT_INDEXES    2
#define EXPERT_REPORT_PLAN       3
#define EXPERT_REPORT_CANDIDATES 4

/*
** Free an (sqlite3expert*) handle and all associated resources. There 
** should be one call to this function for each successful call to 
** sqlite3-expert_new().
*/
void sqlite3_expert_destroy(sqlite3expert*);

#endif  /* !defined(SQLITEEXPERT_H) */

/************************* End ext/expert/sqlite3expert.h ********************/
/************************* Begin ext/expert/sqlite3expert.c ******************/
/*
** 2017 April 09
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/
/* #include "sqlite3expert.h" */
#include <assert.h>
#include <string.h>
#include <stdio.h>

#if !defined(SQLITE_AMALGAMATION)
#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
# define SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS 1
#endif
#if defined(SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS)
# define ALWAYS(X)      (1)
# define NEVER(X)       (0)
#elif !defined(NDEBUG)
# define ALWAYS(X)      ((X)?1:(assert(0),0))
# define NEVER(X)       ((X)?(assert(0),1):0)
#else
# define ALWAYS(X)      (X)
# define NEVER(X)       (X)
#endif
#endif /* !defined(SQLITE_AMALGAMATION) */


#ifndef SQLITE_OMIT_VIRTUALTABLE

/* typedef sqlite3_int64 i64; */
/* typedef sqlite3_uint64 u64; */

typedef struct IdxColumn IdxColumn;
typedef struct IdxConstraint IdxConstraint;
typedef struct IdxScan IdxScan;
typedef struct IdxStatement IdxStatement;
typedef struct IdxTable IdxTable;
typedef struct IdxWrite IdxWrite;

#define STRLEN  (int)strlen

/*
** A temp table name that we assume no user database will actually use.
** If this assumption proves incorrect triggers on the table with the
** conflicting name will be ignored.
*/
#define UNIQUE_TABLE_NAME "t592690916721053953805701627921227776"

/*
** A single constraint. Equivalent to either "col = ?" or "col < ?" (or
** any other type of single-ended range constraint on a column).
**
** pLink:
**   Used to temporarily link IdxConstraint objects into lists while
**   creating candidate indexes.
*/
struct IdxConstraint {
  char *zColl;                    /* Collation sequence */
  int bRange;                     /* True for range, false for eq */
  int iCol;                       /* Constrained table column */
  int bFlag;                      /* Used by idxFindCompatible() */
  int bDesc;                      /* True if ORDER BY <expr> DESC */
  IdxConstraint *pNext;           /* Next constraint in pEq or pRange list */
  IdxConstraint *pLink;           /* See above */
};

/*
** A single scan of a single table.
*/
struct IdxScan {
  IdxTable *pTab;                 /* Associated table object */
  int iDb;                        /* Database containing table zTable */
  i64 covering;                   /* Mask of columns required for cov. index */
  IdxConstraint *pOrder;          /* ORDER BY columns */
  IdxConstraint *pEq;             /* List of == constraints */
  IdxConstraint *pRange;          /* List of < constraints */
  IdxScan *pNextScan;             /* Next IdxScan object for same analysis */
};

/*
** Information regarding a single database table. Extracted from 
** "PRAGMA table_info" by function idxGetTableInfo().
*/
struct IdxColumn {
  char *zName;
  char *zColl;
  int iPk;
};
struct IdxTable {
  int nCol;
  char *zName;                    /* Table name */
  IdxColumn *aCol;
  IdxTable *pNext;                /* Next table in linked list of all tables */
};

/*
** An object of the following type is created for each unique table/write-op
** seen. The objects are stored in a singly-linked list beginning at
** sqlite3expert.pWrite.
*/
struct IdxWrite {
  IdxTable *pTab;
  int eOp;                        /* SQLITE_UPDATE, DELETE or INSERT */
  IdxWrite *pNext;
};

/*
** Each statement being analyzed is represented by an instance of this
** structure.
*/
struct IdxStatement {
  int iId;                        /* Statement number */
  char *zSql;                     /* SQL statement */
  char *zIdx;                     /* Indexes */
  char *zEQP;                     /* Plan */
  IdxStatement *pNext;
};


/*
** A hash table for storing strings. With space for a payload string
** with each entry. Methods are:
**
**   idxHashInit()
**   idxHashClear()
**   idxHashAdd()
**   idxHashSearch()
*/
#define IDX_HASH_SIZE 1023
typedef struct IdxHashEntry IdxHashEntry;
typedef struct IdxHash IdxHash;
struct IdxHashEntry {
  char *zKey;                     /* nul-terminated key */
  char *zVal;                     /* nul-terminated value string */
  char *zVal2;                    /* nul-terminated value string 2 */
  IdxHashEntry *pHashNext;        /* Next entry in same hash bucket */
  IdxHashEntry *pNext;            /* Next entry in hash */
};
struct IdxHash {
  IdxHashEntry *pFirst;
  IdxHashEntry *aHash[IDX_HASH_SIZE];
};

/*
** sqlite3expert object.
*/
struct sqlite3expert {
  int iSample;                    /* Percentage of tables to sample for stat1 */
  sqlite3 *db;                    /* User database */
  sqlite3 *dbm;                   /* In-memory db for this analysis */
  sqlite3 *dbv;                   /* Vtab schema for this analysis */
  IdxTable *pTable;               /* List of all IdxTable objects */
  IdxScan *pScan;                 /* List of scan objects */
  IdxWrite *pWrite;               /* List of write objects */
  IdxStatement *pStatement;       /* List of IdxStatement objects */
  int bRun;                       /* True once analysis has run */
  char **pzErrmsg;
  int rc;                         /* Error code from whereinfo hook */
  IdxHash hIdx;                   /* Hash containing all candidate indexes */
  char *zCandidates;              /* For EXPERT_REPORT_CANDIDATES */
};


/*
** Allocate and return nByte bytes of zeroed memory using sqlite3_malloc(). 
** If the allocation fails, set *pRc to SQLITE_NOMEM and return NULL.
*/
static void *idxMalloc(int *pRc, i64 nByte){
  void *pRet;
  assert( *pRc==SQLITE_OK );
  assert( nByte>0 );
  pRet = sqlite3_malloc64(nByte);
  if( pRet ){
    memset(pRet, 0, nByte);
  }else{
    *pRc = SQLITE_NOMEM;
  }
  return pRet;
}

/*
** Initialize an IdxHash hash table.
*/
static void idxHashInit(IdxHash *pHash){
  memset(pHash, 0, sizeof(IdxHash));
}

/*
** Reset an IdxHash hash table.
*/
static void idxHashClear(IdxHash *pHash){
  int i;
  for(i=0; i<IDX_HASH_SIZE; i++){
    IdxHashEntry *pEntry;
    IdxHashEntry *pNext;
    for(pEntry=pHash->aHash[i]; pEntry; pEntry=pNext){
      pNext = pEntry->pHashNext;
      sqlite3_free(pEntry->zVal2);
      sqlite3_free(pEntry);
    }
  }
  memset(pHash, 0, sizeof(IdxHash));
}

/*
** Return the index of the hash bucket that the string specified by the
** arguments to this function belongs.
*/
static int idxHashString(const char *z, int n){
  unsigned int ret = 0;
  int i;
  for(i=0; i<n; i++){
    ret += (ret<<3) + (unsigned char)(z[i]);
  }
  return (int)(ret % IDX_HASH_SIZE);
}

/*
** If zKey is already present in the hash table, return non-zero and do
** nothing. Otherwise, add an entry with key zKey and payload string zVal to
** the hash table passed as the second argument. 
*/
static int idxHashAdd(
  int *pRc, 
  IdxHash *pHash, 
  const char *zKey,
  const char *zVal
){
  int nKey = STRLEN(zKey);
  int iHash = idxHashString(zKey, nKey);
  int nVal = (zVal ? STRLEN(zVal) : 0);
  IdxHashEntry *pEntry;
  assert( iHash>=0 );
  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
      return 1;
    }
  }
  pEntry = idxMalloc(pRc, sizeof(IdxHashEntry) + (i64)nKey+1 + (i64)nVal+1);
  if( pEntry ){
    pEntry->zKey = (char*)&pEntry[1];
    memcpy(pEntry->zKey, zKey, nKey);
    if( zVal ){
      pEntry->zVal = &pEntry->zKey[nKey+1];
      memcpy(pEntry->zVal, zVal, nVal);
    }
    pEntry->pHashNext = pHash->aHash[iHash];
    pHash->aHash[iHash] = pEntry;

    pEntry->pNext = pHash->pFirst;
    pHash->pFirst = pEntry;
  }
  return 0;
}

/*
** If zKey/nKey is present in the hash table, return a pointer to the 
** hash-entry object.
*/
static IdxHashEntry *idxHashFind(IdxHash *pHash, const char *zKey, int nKey){
  int iHash;
  IdxHashEntry *pEntry;
  if( nKey<0 ) nKey = STRLEN(zKey);
  iHash = idxHashString(zKey, nKey);
  assert( iHash>=0 );
  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
      return pEntry;
    }
  }
  return 0;
}

/*
** If the hash table contains an entry with a key equal to the string
** passed as the final two arguments to this function, return a pointer
** to the payload string. Otherwise, if zKey/nKey is not present in the
** hash table, return NULL.
*/
static const char *idxHashSearch(IdxHash *pHash, const char *zKey, int nKey){
  IdxHashEntry *pEntry = idxHashFind(pHash, zKey, nKey);
  if( pEntry ) return pEntry->zVal;
  return 0;
}

/*
** Allocate and return a new IdxConstraint object. Set the IdxConstraint.zColl
** variable to point to a copy of nul-terminated string zColl.
*/
static IdxConstraint *idxNewConstraint(int *pRc, const char *zColl){
  IdxConstraint *pNew;
  int nColl = STRLEN(zColl);

  assert( *pRc==SQLITE_OK );
  pNew = (IdxConstraint*)idxMalloc(pRc, sizeof(IdxConstraint) * nColl + 1);
  if( pNew ){
    pNew->zColl = (char*)&pNew[1];
    memcpy(pNew->zColl, zColl, nColl+1);
  }
  return pNew;
}

/*
** An error associated with database handle db has just occurred. Pass
** the error message to callback function xOut.
*/
static void idxDatabaseError(
  sqlite3 *db,                    /* Database handle */
  char **pzErrmsg                 /* Write error here */
){
  *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
}

/*
** Prepare an SQL statement.
*/
static int idxPrepareStmt(
  sqlite3 *db,                    /* Database handle to compile against */
  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
  const char *zSql                /* SQL statement to compile */
){
  int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
  if( rc!=SQLITE_OK ){
    *ppStmt = 0;
    idxDatabaseError(db, pzErrmsg);
  }
  return rc;
}

/*
** Prepare an SQL statement using the results of a printf() formatting.
*/
static int idxPrintfPrepareStmt(
  sqlite3 *db,                    /* Database handle to compile against */
  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
  const char *zFmt,               /* printf() format of SQL statement */
  ...                             /* Trailing printf() arguments */
){
  va_list ap;
  int rc;
  char *zSql;
  va_start(ap, zFmt);
  zSql = sqlite3_vmprintf(zFmt, ap);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = idxPrepareStmt(db, ppStmt, pzErrmsg, zSql);
    sqlite3_free(zSql);
  }
  va_end(ap);
  return rc;
}


/*************************************************************************
** Beginning of virtual table implementation.
*/
typedef struct ExpertVtab ExpertVtab;
struct ExpertVtab {
  sqlite3_vtab base;
  IdxTable *pTab;
  sqlite3expert *pExpert;
};

typedef struct ExpertCsr ExpertCsr;
struct ExpertCsr {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pData;
};

static char *expertDequote(const char *zIn){
  i64 n = STRLEN(zIn);
  char *zRet = sqlite3_malloc64(n);

  assert( zIn[0]=='\'' );
  assert( zIn[n-1]=='\'' );

  if( zRet ){
    i64 iOut = 0;
    i64 iIn = 0;
    for(iIn=1; iIn<(n-1); iIn++){
      if( zIn[iIn]=='\'' ){
        assert( zIn[iIn+1]=='\'' );
        iIn++;
      }
      zRet[iOut++] = zIn[iIn];
    }
    zRet[iOut] = '\0';
  }

  return zRet;
}

/* 
** This function is the implementation of both the xConnect and xCreate
** methods of the r-tree virtual table.
**
**   argv[0]   -> module name
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> column names...
*/
static int expertConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  sqlite3expert *pExpert = (sqlite3expert*)pAux;
  ExpertVtab *p = 0;
  int rc;

  if( argc!=4 ){
    *pzErr = sqlite3_mprintf("internal error!");
    rc = SQLITE_ERROR;
  }else{
    char *zCreateTable = expertDequote(argv[3]);
    if( zCreateTable ){
      rc = sqlite3_declare_vtab(db, zCreateTable);
      if( rc==SQLITE_OK ){
        p = idxMalloc(&rc, sizeof(ExpertVtab));
      }
      if( rc==SQLITE_OK ){
        p->pExpert = pExpert;
        p->pTab = pExpert->pTable;
        assert( sqlite3_stricmp(p->pTab->zName, argv[2])==0 );
      }
      sqlite3_free(zCreateTable);
    }else{
      rc = SQLITE_NOMEM;
    }
  }

  *ppVtab = (sqlite3_vtab*)p;
  return rc;
}

static int expertDisconnect(sqlite3_vtab *pVtab){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  sqlite3_free(p);
  return SQLITE_OK;
}

static int expertBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  int rc = SQLITE_OK;
  int n = 0;
  IdxScan *pScan;
  const int opmask = 
    SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_GT |
    SQLITE_INDEX_CONSTRAINT_LT | SQLITE_INDEX_CONSTRAINT_GE |
    SQLITE_INDEX_CONSTRAINT_LE;

  pScan = idxMalloc(&rc, sizeof(IdxScan));
  if( pScan ){
    int i;

    /* Link the new scan object into the list */
    pScan->pTab = p->pTab;
    pScan->pNextScan = p->pExpert->pScan;
    p->pExpert->pScan = pScan;

    /* Add the constraints to the IdxScan object */
    for(i=0; i<pIdxInfo->nConstraint; i++){
      struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
      if( pCons->usable 
       && pCons->iColumn>=0 
       && p->pTab->aCol[pCons->iColumn].iPk==0
       && (pCons->op & opmask) 
      ){
        IdxConstraint *pNew;
        const char *zColl = sqlite3_vtab_collation(pIdxInfo, i);
        pNew = idxNewConstraint(&rc, zColl);
        if( pNew ){
          pNew->iCol = pCons->iColumn;
          if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
            pNew->pNext = pScan->pEq;
            pScan->pEq = pNew;
          }else{
            pNew->bRange = 1;
            pNew->pNext = pScan->pRange;
            pScan->pRange = pNew;
          }
        }
        n++;
        pIdxInfo->aConstraintUsage[i].argvIndex = n;
      }
    }

    /* Add the ORDER BY to the IdxScan object */
    for(i=pIdxInfo->nOrderBy-1; i>=0; i--){
      int iCol = pIdxInfo->aOrderBy[i].iColumn;
      if( iCol>=0 ){
        IdxConstraint *pNew = idxNewConstraint(&rc, p->pTab->aCol[iCol].zColl);
        if( pNew ){
          pNew->iCol = iCol;
          pNew->bDesc = pIdxInfo->aOrderBy[i].desc;
          pNew->pNext = pScan->pOrder;
          pNew->pLink = pScan->pOrder;
          pScan->pOrder = pNew;
          n++;
        }
      }
    }
  }

  pIdxInfo->estimatedCost = 1000000.0 / (n+1);
  return rc;
}

static int expertUpdate(
  sqlite3_vtab *pVtab, 
  int nData, 
  sqlite3_value **azData, 
  sqlite_int64 *pRowid
){
  (void)pVtab;
  (void)nData;
  (void)azData;
  (void)pRowid;
  return SQLITE_OK;
}

/* 
** Virtual table module xOpen method.
*/
static int expertOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  int rc = SQLITE_OK;
  ExpertCsr *pCsr;
  (void)pVTab;
  pCsr = idxMalloc(&rc, sizeof(ExpertCsr));
  *ppCursor = (sqlite3_vtab_cursor*)pCsr;
  return rc;
}

/* 
** Virtual table module xClose method.
*/
static int expertClose(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  sqlite3_finalize(pCsr->pData);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Virtual table module xEof method.
**
** Return non-zero if the cursor does not currently point to a valid 
** record (i.e if the scan has finished), or zero otherwise.
*/
static int expertEof(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  return pCsr->pData==0;
}

/* 
** Virtual table module xNext method.
*/
static int expertNext(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  int rc = SQLITE_OK;

  assert( pCsr->pData );
  rc = sqlite3_step(pCsr->pData);
  if( rc!=SQLITE_ROW ){
    rc = sqlite3_finalize(pCsr->pData);
    pCsr->pData = 0;
  }else{
    rc = SQLITE_OK;
  }

  return rc;
}

/* 
** Virtual table module xRowid method.
*/
static int expertRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  (void)cur;
  *pRowid = 0;
  return SQLITE_OK;
}

/* 
** Virtual table module xColumn method.
*/
static int expertColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  sqlite3_value *pVal;
  pVal = sqlite3_column_value(pCsr->pData, i);
  if( pVal ){
    sqlite3_result_value(ctx, pVal);
  }
  return SQLITE_OK;
}

/* 
** Virtual table module xFilter method.
*/
static int expertFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  ExpertVtab *pVtab = (ExpertVtab*)(cur->pVtab);
  sqlite3expert *pExpert = pVtab->pExpert;
  int rc;

  (void)idxNum;
  (void)idxStr;
  (void)argc;
  (void)argv;
  rc = sqlite3_finalize(pCsr->pData);
  pCsr->pData = 0;
  if( rc==SQLITE_OK ){
    rc = idxPrintfPrepareStmt(pExpert->db, &pCsr->pData, &pVtab->base.zErrMsg,
        "SELECT * FROM main.%Q WHERE sqlite_expert_sample()", pVtab->pTab->zName
    );
  }

  if( rc==SQLITE_OK ){
    rc = expertNext(cur);
  }
  return rc;
}

static int idxRegisterVtab(sqlite3expert *p){
  static const sqlite3_module expertModule = {
    2,                            /* iVersion */
    expertConnect,                /* xCreate - create a table */
    expertConnect,                /* xConnect - connect to an existing table */
    expertBestIndex,              /* xBestIndex - Determine search strategy */
    expertDisconnect,             /* xDisconnect - Disconnect from a table */
    expertDisconnect,             /* xDestroy - Drop a table */
    expertOpen,                   /* xOpen - open a cursor */
    expertClose,                  /* xClose - close a cursor */
    expertFilter,                 /* xFilter - configure scan constraints */
    expertNext,                   /* xNext - advance a cursor */
    expertEof,                    /* xEof */
    expertColumn,                 /* xColumn - read data */
    expertRowid,                  /* xRowid - read data */
    expertUpdate,                 /* xUpdate - write data */
    0,                            /* xBegin - begin transaction */
    0,                            /* xSync - sync transaction */
    0,                            /* xCommit - commit transaction */
    0,                            /* xRollback - rollback transaction */
    0,                            /* xFindFunction - function overloading */
    0,                            /* xRename - rename the table */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
    0,                            /* xShadowName */
    0,                            /* xIntegrity */
  };

  return sqlite3_create_module(p->dbv, "expert", &expertModule, (void*)p);
}
/*
** End of virtual table implementation.
*************************************************************************/
/*
** Finalize SQL statement pStmt. If (*pRc) is SQLITE_OK when this function
** is called, set it to the return value of sqlite3_finalize() before
** returning. Otherwise, discard the sqlite3_finalize() return value.
*/
static void idxFinalize(int *pRc, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

/*
** Attempt to allocate an IdxTable structure corresponding to table zTab
** in the main database of connection db. If successful, set (*ppOut) to
** point to the new object and return SQLITE_OK. Otherwise, return an
** SQLite error code and set (*ppOut) to NULL. In this case *pzErrmsg may be
** set to point to an error string.
**
** It is the responsibility of the caller to eventually free either the
** IdxTable object or error message using sqlite3_free().
*/
static int idxGetTableInfo(
  sqlite3 *db,                    /* Database connection to read details from */
  const char *zTab,               /* Table name */
  IdxTable **ppOut,               /* OUT: New object (if successful) */
  char **pzErrmsg                 /* OUT: Error message (if not) */
){
  sqlite3_stmt *p1 = 0;
  int nCol = 0;
  int nTab;
  i64 nByte;
  IdxTable *pNew = 0;
  int rc, rc2;
  char *pCsr = 0;
  int nPk = 0;

  *ppOut = 0;
  if( zTab==0 ) return SQLITE_ERROR;
  nTab = STRLEN(zTab);
  nByte = sizeof(IdxTable) + nTab + 1;
  rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_xinfo=%Q", zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    const char *zColSeq = 0;
    if( zCol==0 ){
      rc = SQLITE_ERROR;
      break;
    }
    nByte += 1 + STRLEN(zCol);
    rc = sqlite3_table_column_metadata(
        db, "main", zTab, zCol, 0, &zColSeq, 0, 0, 0
    );
    if( zColSeq==0 ) zColSeq = "binary";
    nByte += 1 + STRLEN(zColSeq);
    nCol++;
    nPk += (sqlite3_column_int(p1, 5)>0);
  }
  rc2 = sqlite3_reset(p1);
  if( rc==SQLITE_OK ) rc = rc2;

  nByte += sizeof(IdxColumn) * nCol;
  if( rc==SQLITE_OK ){
    pNew = idxMalloc(&rc, nByte);
  }
  if( rc==SQLITE_OK ){
    pNew->aCol = (IdxColumn*)&pNew[1];
    pNew->nCol = nCol;
    pCsr = (char*)&pNew->aCol[nCol];
  }

  nCol = 0;
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    const char *zColSeq = 0;
    int nCopy;
    if( zCol==0 ) continue;
    nCopy = STRLEN(zCol) + 1;
    pNew->aCol[nCol].zName = pCsr;
    pNew->aCol[nCol].iPk = (sqlite3_column_int(p1, 5)==1 && nPk==1);
    memcpy(pCsr, zCol, nCopy);
    pCsr += nCopy;

    rc = sqlite3_table_column_metadata(
        db, "main", zTab, zCol, 0, &zColSeq, 0, 0, 0
    );
    if( rc==SQLITE_OK ){
      if( zColSeq==0 ) zColSeq = "binary";
      nCopy = STRLEN(zColSeq) + 1;
      pNew->aCol[nCol].zColl = pCsr;
      memcpy(pCsr, zColSeq, nCopy);
      pCsr += nCopy;
    }

    nCol++;
  }
  idxFinalize(&rc, p1);

  if( rc!=SQLITE_OK ){
    sqlite3_free(pNew);
    pNew = 0;
  }else if( ALWAYS(pNew!=0) ){
    pNew->zName = pCsr;
    if( ALWAYS(pNew->zName!=0) ) memcpy(pNew->zName, zTab, nTab+1);
  }

  *ppOut = pNew;
  return rc;
}

/*
** This function is a no-op if *pRc is set to anything other than 
** SQLITE_OK when it is called.
**
** If *pRc is initially set to SQLITE_OK, then the text specified by
** the printf() style arguments is appended to zIn and the result returned
** in a buffer allocated by sqlite3_malloc(). sqlite3_free() is called on
** zIn before returning.
*/
static char *idxAppendText(int *pRc, char *zIn, const char *zFmt, ...){
  va_list ap;
  char *zAppend = 0;
  char *zRet = 0;
  i64 nIn = zIn ? STRLEN(zIn) : 0;
  i64 nAppend = 0;
  va_start(ap, zFmt);
  if( *pRc==SQLITE_OK ){
    zAppend = sqlite3_vmprintf(zFmt, ap);
    if( zAppend ){
      nAppend = STRLEN(zAppend);
      zRet = (char*)sqlite3_malloc64(nIn + nAppend + 1);
    }
    if( zAppend && zRet ){
      if( nIn ) memcpy(zRet, zIn, nIn);
      memcpy(&zRet[nIn], zAppend, nAppend+1);
    }else{
      sqlite3_free(zRet);
      zRet = 0;
      *pRc = SQLITE_NOMEM;
    }
    sqlite3_free(zAppend);
    sqlite3_free(zIn);
  }
  va_end(ap);
  return zRet;
}

/*
** Return true if zId must be quoted in order to use it as an SQL
** identifier, or false otherwise.
*/
static int idxIdentifierRequiresQuotes(const char *zId){
  int i;
  int nId = STRLEN(zId);
  
  if( sqlite3_keyword_check(zId, nId) ) return 1;

  for(i=0; zId[i]; i++){
    if( !(zId[i]=='_')
     && !(zId[i]>='0' && zId[i]<='9')
     && !(zId[i]>='a' && zId[i]<='z')
     && !(zId[i]>='A' && zId[i]<='Z')
    ){
      return 1;
    }
  }
  return 0;
}

/*
** This function appends an index column definition suitable for constraint
** pCons to the string passed as zIn and returns the result.
*/
static char *idxAppendColDefn(
  int *pRc,                       /* IN/OUT: Error code */
  char *zIn,                      /* Column defn accumulated so far */
  IdxTable *pTab,                 /* Table index will be created on */
  IdxConstraint *pCons
){
  char *zRet = zIn;
  IdxColumn *p = &pTab->aCol[pCons->iCol];
  if( zRet ) zRet = idxAppendText(pRc, zRet, ", ");

  if( idxIdentifierRequiresQuotes(p->zName) ){
    zRet = idxAppendText(pRc, zRet, "%Q", p->zName);
  }else{
    zRet = idxAppendText(pRc, zRet, "%s", p->zName);
  }

  if( sqlite3_stricmp(p->zColl, pCons->zColl) ){
    if( idxIdentifierRequiresQuotes(pCons->zColl) ){
      zRet = idxAppendText(pRc, zRet, " COLLATE %Q", pCons->zColl);
    }else{
      zRet = idxAppendText(pRc, zRet, " COLLATE %s", pCons->zColl);
    }
  }

  if( pCons->bDesc ){
    zRet = idxAppendText(pRc, zRet, " DESC");
  }
  return zRet;
}

/*
** Search database dbm for an index compatible with the one idxCreateFromCons()
** would create from arguments pScan, pEq and pTail. If no error occurs and 
** such an index is found, return non-zero. Or, if no such index is found,
** return zero.
**
** If an error occurs, set *pRc to an SQLite error code and return zero.
*/
static int idxFindCompatible(
  int *pRc,                       /* OUT: Error code */
  sqlite3* dbm,                   /* Database to search */
  IdxScan *pScan,                 /* Scan for table to search for index on */
  IdxConstraint *pEq,             /* List of == constraints */
  IdxConstraint *pTail            /* List of range constraints */
){
  const char *zTbl = pScan->pTab->zName;
  sqlite3_stmt *pIdxList = 0;
  IdxConstraint *pIter;
  int nEq = 0;                    /* Number of elements in pEq */
  int rc;

  /* Count the elements in list pEq */
  for(pIter=pEq; pIter; pIter=pIter->pLink) nEq++;

  rc = idxPrintfPrepareStmt(dbm, &pIdxList, 0, "PRAGMA index_list=%Q", zTbl);
  while( rc==SQLITE_OK && sqlite3_step(pIdxList)==SQLITE_ROW ){
    int bMatch = 1;
    IdxConstraint *pT = pTail;
    sqlite3_stmt *pInfo = 0;
    const char *zIdx = (const char*)sqlite3_column_text(pIdxList, 1);
    if( zIdx==0 ) continue;

    /* Zero the IdxConstraint.bFlag values in the pEq list */
    for(pIter=pEq; pIter; pIter=pIter->pLink) pIter->bFlag = 0;

    rc = idxPrintfPrepareStmt(dbm, &pInfo, 0, "PRAGMA index_xInfo=%Q", zIdx);
    while( rc==SQLITE_OK && sqlite3_step(pInfo)==SQLITE_ROW ){
      int iIdx = sqlite3_column_int(pInfo, 0);
      int iCol = sqlite3_column_int(pInfo, 1);
      const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);

      if( iIdx<nEq ){
        for(pIter=pEq; pIter; pIter=pIter->pLink){
          if( pIter->bFlag ) continue;
          if( pIter->iCol!=iCol ) continue;
          if( sqlite3_stricmp(pIter->zColl, zColl) ) continue;
          pIter->bFlag = 1;
          break;
        }
        if( pIter==0 ){
          bMatch = 0;
          break;
        }
      }else{
        if( pT ){
          if( pT->iCol!=iCol || sqlite3_stricmp(pT->zColl, zColl) ){
            bMatch = 0;
            break;
          }
          pT = pT->pLink;
        }
      }
    }
    idxFinalize(&rc, pInfo);

    if( rc==SQLITE_OK && bMatch ){
      sqlite3_finalize(pIdxList);
      return 1;
    }
  }
  idxFinalize(&rc, pIdxList);

  *pRc = rc;
  return 0;
}

/* Callback for sqlite3_exec() with query with leading count(*) column.
 * The first argument is expected to be an int*, referent to be incremented
 * if that leading column is not exactly '0'.
 */
static int countNonzeros(void* pCount, int nc,
                         char* azResults[], char* azColumns[]){
  (void)azColumns;  /* Suppress unused parameter warning */
  if( nc>0 && (azResults[0][0]!='0' || azResults[0][1]!=0) ){
    *((int *)pCount) += 1;
  }
  return 0;
}

static int idxCreateFromCons(
  sqlite3expert *p,
  IdxScan *pScan,
  IdxConstraint *pEq, 
  IdxConstraint *pTail
){
  sqlite3 *dbm = p->dbm;
  int rc = SQLITE_OK;
  if( (pEq || pTail) && 0==idxFindCompatible(&rc, dbm, pScan, pEq, pTail) ){
    IdxTable *pTab = pScan->pTab;
    char *zCols = 0;
    char *zIdx = 0;
    IdxConstraint *pCons;
    unsigned int h = 0;
    const char *zFmt;

    for(pCons=pEq; pCons; pCons=pCons->pLink){
      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
    }
    for(pCons=pTail; pCons; pCons=pCons->pLink){
      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
    }

    if( rc==SQLITE_OK ){
      /* Hash the list of columns to come up with a name for the index */
      const char *zTable = pScan->pTab->zName;
      int quoteTable = idxIdentifierRequiresQuotes(zTable);
      char *zName = 0;          /* Index name */
      int collisions = 0;
      do{
        int i;
        char *zFind;
        for(i=0; zCols[i]; i++){
          h += ((h<<3) + zCols[i]);
        }
        sqlite3_free(zName);
        zName = sqlite3_mprintf("%s_idx_%08x", zTable, h);
        if( zName==0 ) break;
        /* Is is unique among table, view and index names? */
        zFmt = "SELECT count(*) FROM sqlite_schema WHERE name=%Q"
          " AND type in ('index','table','view')";
        zFind = sqlite3_mprintf(zFmt, zName);
        i = 0;
        rc = sqlite3_exec(dbm, zFind, countNonzeros, &i, 0);
        assert(rc==SQLITE_OK);
        sqlite3_free(zFind);
        if( i==0 ){
          collisions = 0;
          break;
        }
        ++collisions;
      }while( collisions<50 && zName!=0 );
      if( collisions ){
        /* This return means "Gave up trying to find a unique index name." */
        rc = SQLITE_BUSY_TIMEOUT;
      }else if( zName==0 ){
        rc = SQLITE_NOMEM;
      }else{
        if( quoteTable ){
          zFmt = "CREATE INDEX \"%w\" ON \"%w\"(%s)";
        }else{
          zFmt = "CREATE INDEX %s ON %s(%s)";
        }
        zIdx = sqlite3_mprintf(zFmt, zName, zTable, zCols);
        if( !zIdx ){
          rc = SQLITE_NOMEM;
        }else{
          rc = sqlite3_exec(dbm, zIdx, 0, 0, p->pzErrmsg);
          if( rc!=SQLITE_OK ){
            rc = SQLITE_BUSY_TIMEOUT;
          }else{
            idxHashAdd(&rc, &p->hIdx, zName, zIdx);
          }
        }
        sqlite3_free(zName);
        sqlite3_free(zIdx);
      }
    }

    sqlite3_free(zCols);
  }
  return rc;
}

/*
** Return true if list pList (linked by IdxConstraint.pLink) contains
** a constraint compatible with *p. Otherwise return false.
*/
static int idxFindConstraint(IdxConstraint *pList, IdxConstraint *p){
  IdxConstraint *pCmp;
  for(pCmp=pList; pCmp; pCmp=pCmp->pLink){
    if( p->iCol==pCmp->iCol ) return 1;
  }
  return 0;
}

static int idxCreateFromWhere(
  sqlite3expert *p, 
  IdxScan *pScan,                 /* Create indexes for this scan */
  IdxConstraint *pTail            /* range/ORDER BY constraints for inclusion */
){
  IdxConstraint *p1 = 0;
  IdxConstraint *pCon;
  int rc;

  /* Gather up all the == constraints. */
  for(pCon=pScan->pEq; pCon; pCon=pCon->pNext){
    if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
      pCon->pLink = p1;
      p1 = pCon;
    }
  }

  /* Create an index using the == constraints collected above. And the
  ** range constraint/ORDER BY terms passed in by the caller, if any. */
  rc = idxCreateFromCons(p, pScan, p1, pTail);

  /* If no range/ORDER BY passed by the caller, create a version of the
  ** index for each range constraint.  */
  if( pTail==0 ){
    for(pCon=pScan->pRange; rc==SQLITE_OK && pCon; pCon=pCon->pNext){
      assert( pCon->pLink==0 );
      if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
        rc = idxCreateFromCons(p, pScan, p1, pCon);
      }
    }
  }

  return rc;
}

/*
** Create candidate indexes in database [dbm] based on the data in 
** linked-list pScan.
*/
static int idxCreateCandidates(sqlite3expert *p){
  int rc = SQLITE_OK;
  IdxScan *pIter;

  for(pIter=p->pScan; pIter && rc==SQLITE_OK; pIter=pIter->pNextScan){
    rc = idxCreateFromWhere(p, pIter, 0);
    if( rc==SQLITE_OK && pIter->pOrder ){
      rc = idxCreateFromWhere(p, pIter, pIter->pOrder);
    }
  }

  return rc;
}

/*
** Free all elements of the linked list starting at pConstraint.
*/
static void idxConstraintFree(IdxConstraint *pConstraint){
  IdxConstraint *pNext;
  IdxConstraint *p;

  for(p=pConstraint; p; p=pNext){
    pNext = p->pNext;
    sqlite3_free(p);
  }
}

/*
** Free all elements of the linked list starting from pScan up until pLast
** (pLast is not freed).
*/
static void idxScanFree(IdxScan *pScan, IdxScan *pLast){
  IdxScan *p;
  IdxScan *pNext;
  for(p=pScan; p!=pLast; p=pNext){
    pNext = p->pNextScan;
    idxConstraintFree(p->pOrder);
    idxConstraintFree(p->pEq);
    idxConstraintFree(p->pRange);
    sqlite3_free(p);
  }
}

/*
** Free all elements of the linked list starting from pStatement up 
** until pLast (pLast is not freed).
*/
static void idxStatementFree(IdxStatement *pStatement, IdxStatement *pLast){
  IdxStatement *p;
  IdxStatement *pNext;
  for(p=pStatement; p!=pLast; p=pNext){
    pNext = p->pNext;
    sqlite3_free(p->zEQP);
    sqlite3_free(p->zIdx);
    sqlite3_free(p);
  }
}

/*
** Free the linked list of IdxTable objects starting at pTab.
*/
static void idxTableFree(IdxTable *pTab){
  IdxTable *pIter;
  IdxTable *pNext;
  for(pIter=pTab; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_free(pIter);
  }
}

/*
** Free the linked list of IdxWrite objects starting at pTab.
*/
static void idxWriteFree(IdxWrite *pTab){
  IdxWrite *pIter;
  IdxWrite *pNext;
  for(pIter=pTab; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_free(pIter);
  }
}



/*
** This function is called after candidate indexes have been created. It
** runs all the queries to see which indexes they prefer, and populates
** IdxStatement.zIdx and IdxStatement.zEQP with the results.
*/
static int idxFindIndexes(
  sqlite3expert *p,
  char **pzErr                         /* OUT: Error message (sqlite3_malloc) */
){
  IdxStatement *pStmt;
  sqlite3 *dbm = p->dbm;
  int rc = SQLITE_OK;

  IdxHash hIdx;
  idxHashInit(&hIdx);

  for(pStmt=p->pStatement; rc==SQLITE_OK && pStmt; pStmt=pStmt->pNext){
    IdxHashEntry *pEntry;
    sqlite3_stmt *pExplain = 0;
    idxHashClear(&hIdx);
    rc = idxPrintfPrepareStmt(dbm, &pExplain, pzErr,
        "EXPLAIN QUERY PLAN %s", pStmt->zSql
    );
    while( rc==SQLITE_OK && sqlite3_step(pExplain)==SQLITE_ROW ){
      /* int iId = sqlite3_column_int(pExplain, 0); */
      /* int iParent = sqlite3_column_int(pExplain, 1); */
      /* int iNotUsed = sqlite3_column_int(pExplain, 2); */
      const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
      int nDetail;
      int i;

      if( !zDetail ) continue;
      nDetail = STRLEN(zDetail);

      for(i=0; i<nDetail; i++){
        const char *zIdx = 0;
        if( i+13<nDetail && memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
          zIdx = &zDetail[i+13];
        }else if( i+22<nDetail 
            && memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 
        ){
          zIdx = &zDetail[i+22];
        }
        if( zIdx ){
          const char *zSql;
          int nIdx = 0;
          while( zIdx[nIdx]!='\0' && (zIdx[nIdx]!=' ' || zIdx[nIdx+1]!='(') ){
            nIdx++;
          }
          zSql = idxHashSearch(&p->hIdx, zIdx, nIdx);
          if( zSql ){
            idxHashAdd(&rc, &hIdx, zSql, 0);
            if( rc ) goto find_indexes_out;
          }
          break;
        }
      }

      if( zDetail[0]!='-' ){
        pStmt->zEQP = idxAppendText(&rc, pStmt->zEQP, "%s\n", zDetail);
      }
    }

    for(pEntry=hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
      pStmt->zIdx = idxAppendText(&rc, pStmt->zIdx, "%s;\n", pEntry->zKey);
    }

    idxFinalize(&rc, pExplain);
  }

 find_indexes_out:
  idxHashClear(&hIdx);
  return rc;
}

static int idxAuthCallback(
  void *pCtx,
  int eOp,
  const char *z3,
  const char *z4,
  const char *zDb,
  const char *zTrigger
){
  int rc = SQLITE_OK;
  (void)z4;
  (void)zTrigger;
  if( eOp==SQLITE_INSERT || eOp==SQLITE_UPDATE || eOp==SQLITE_DELETE ){
    if( sqlite3_stricmp(zDb, "main")==0 ){
      sqlite3expert *p = (sqlite3expert*)pCtx;
      IdxTable *pTab;
      for(pTab=p->pTable; pTab; pTab=pTab->pNext){
        if( 0==sqlite3_stricmp(z3, pTab->zName) ) break;
      }
      if( pTab ){
        IdxWrite *pWrite;
        for(pWrite=p->pWrite; pWrite; pWrite=pWrite->pNext){
          if( pWrite->pTab==pTab && pWrite->eOp==eOp ) break;
        }
        if( pWrite==0 ){
          pWrite = idxMalloc(&rc, sizeof(IdxWrite));
          if( rc==SQLITE_OK ){
            pWrite->pTab = pTab;
            pWrite->eOp = eOp;
            pWrite->pNext = p->pWrite;
            p->pWrite = pWrite;
          }
        }
      }
    }
  }
  return rc;
}

static int idxProcessOneTrigger(
  sqlite3expert *p, 
  IdxWrite *pWrite, 
  char **pzErr
){
  static const char *zInt = UNIQUE_TABLE_NAME;
  static const char *zDrop = "DROP TABLE " UNIQUE_TABLE_NAME;
  IdxTable *pTab = pWrite->pTab;
  const char *zTab = pTab->zName;
  const char *zSql = 
    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_schema "
    "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
    "ORDER BY type;";
  sqlite3_stmt *pSelect = 0;
  int rc = SQLITE_OK;
  char *zWrite = 0;

  /* Create the table and its triggers in the temp schema */
  rc = idxPrintfPrepareStmt(p->db, &pSelect, pzErr, zSql, zTab, zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSelect) ){
    const char *zCreate = (const char*)sqlite3_column_text(pSelect, 0);
    if( zCreate==0 ) continue;
    rc = sqlite3_exec(p->dbv, zCreate, 0, 0, pzErr);
  }
  idxFinalize(&rc, pSelect);

  /* Rename the table in the temp schema to zInt */
  if( rc==SQLITE_OK ){
    char *z = sqlite3_mprintf("ALTER TABLE temp.%Q RENAME TO %Q", zTab, zInt);
    if( z==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_exec(p->dbv, z, 0, 0, pzErr);
      sqlite3_free(z);
    }
  }

  switch( pWrite->eOp ){
    case SQLITE_INSERT: {
      int i;
      zWrite = idxAppendText(&rc, zWrite, "INSERT INTO %Q VALUES(", zInt);
      for(i=0; i<pTab->nCol; i++){
        zWrite = idxAppendText(&rc, zWrite, "%s?", i==0 ? "" : ", ");
      }
      zWrite = idxAppendText(&rc, zWrite, ")");
      break;
    }
    case SQLITE_UPDATE: {
      int i;
      zWrite = idxAppendText(&rc, zWrite, "UPDATE %Q SET ", zInt);
      for(i=0; i<pTab->nCol; i++){
        zWrite = idxAppendText(&rc, zWrite, "%s%Q=?", i==0 ? "" : ", ", 
            pTab->aCol[i].zName
        );
      }
      break;
    }
    default: {
      assert( pWrite->eOp==SQLITE_DELETE );
      if( rc==SQLITE_OK ){
        zWrite = sqlite3_mprintf("DELETE FROM %Q", zInt);
        if( zWrite==0 ) rc = SQLITE_NOMEM;
      }
    }
  }

  if( rc==SQLITE_OK ){
    sqlite3_stmt *pX = 0;
    rc = sqlite3_prepare_v2(p->dbv, zWrite, -1, &pX, 0);
    idxFinalize(&rc, pX);
    if( rc!=SQLITE_OK ){
      idxDatabaseError(p->dbv, pzErr);
    }
  }
  sqlite3_free(zWrite);

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbv, zDrop, 0, 0, pzErr);
  }

  return rc;
}

static int idxProcessTriggers(sqlite3expert *p, char **pzErr){
  int rc = SQLITE_OK;
  IdxWrite *pEnd = 0;
  IdxWrite *pFirst = p->pWrite;

  while( rc==SQLITE_OK && pFirst!=pEnd ){
    IdxWrite *pIter;
    for(pIter=pFirst; rc==SQLITE_OK && pIter!=pEnd; pIter=pIter->pNext){
      rc = idxProcessOneTrigger(p, pIter, pzErr);
    }
    pEnd = pFirst;
    pFirst = p->pWrite;
  }

  return rc;
}

/*
** This function tests if the schema of the main database of database handle
** db contains an object named zTab. Assuming no error occurs, output parameter
** (*pbContains) is set to true if zTab exists, or false if it does not.
**
** Or, if an error occurs, an SQLite error code is returned. The final value
** of (*pbContains) is undefined in this case.
*/
static int expertDbContainsObject(
  sqlite3 *db, 
  const char *zTab, 
  int *pbContains                 /* OUT: True if object exists */
){
  const char *zSql = "SELECT 1 FROM sqlite_schema WHERE name = ?";
  sqlite3_stmt *pSql = 0;
  int rc = SQLITE_OK;
  int ret = 0;

  rc = sqlite3_prepare_v2(db, zSql, -1, &pSql, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_text(pSql, 1, zTab, -1, SQLITE_STATIC);
    if( SQLITE_ROW==sqlite3_step(pSql) ){
      ret = 1;
    }
    rc = sqlite3_finalize(pSql);
  }

  *pbContains = ret;
  return rc;
}

/*
** Execute SQL command zSql using database handle db. If no error occurs,
** set (*pzErr) to NULL and return SQLITE_OK. 
**
** If an error does occur, return an SQLite error code and set (*pzErr) to
** point to a buffer containing an English language error message. Except,
** if the error message begins with "no such module:", then ignore the
** error and return as if the SQL statement had succeeded.
**
** This is used to copy as much of the database schema as possible while 
** ignoring any errors related to missing virtual table modules.
*/
static int expertSchemaSql(sqlite3 *db, const char *zSql, char **pzErr){
  int rc = SQLITE_OK;
  char *zErr = 0;

  rc = sqlite3_exec(db, zSql, 0, 0, &zErr);
  if( rc!=SQLITE_OK && zErr ){
    int nErr = STRLEN(zErr);
    if( nErr>=15 && memcmp(zErr, "no such module:", 15)==0 ){
      sqlite3_free(zErr);
      rc = SQLITE_OK;
      zErr = 0;
    }
  }

  *pzErr = zErr;
  return rc;
}

static int idxCreateVtabSchema(sqlite3expert *p, char **pzErrmsg){
  int rc = idxRegisterVtab(p);
  sqlite3_stmt *pSchema = 0;

  /* For each table in the main db schema:
  **
  **   1) Add an entry to the p->pTable list, and
  **   2) Create the equivalent virtual table in dbv.
  */
  rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
      "SELECT type, name, sql, 1, "
      "       substr(sql,1,14)=='create virtual' COLLATE nocase "
      "FROM sqlite_schema "
      "WHERE type IN ('table','view') AND "
      "      substr(name,1,7)!='sqlite_' COLLATE nocase "
      " UNION ALL "
      "SELECT type, name, sql, 2, 0 FROM sqlite_schema "
      "WHERE type = 'trigger'"
      "  AND tbl_name IN(SELECT name FROM sqlite_schema WHERE type = 'view') "
      "ORDER BY 4, 5 DESC, 1"
  );
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
    const char *zType = (const char*)sqlite3_column_text(pSchema, 0);
    const char *zName = (const char*)sqlite3_column_text(pSchema, 1);
    const char *zSql = (const char*)sqlite3_column_text(pSchema, 2);
    int bVirtual = sqlite3_column_int(pSchema, 4);
    int bExists = 0;

    if( zType==0 || zName==0 ) continue;
    rc = expertDbContainsObject(p->dbv, zName, &bExists);
    if( rc || bExists ) continue;

    if( zType[0]=='v' || zType[1]=='r' || bVirtual ){
      /* A view. Or a trigger on a view. */
      if( zSql ) rc = expertSchemaSql(p->dbv, zSql, pzErrmsg);
    }else{
      IdxTable *pTab;
      rc = idxGetTableInfo(p->db, zName, &pTab, pzErrmsg);
      if( rc==SQLITE_OK && ALWAYS(pTab!=0) ){
        int i;
        char *zInner = 0;
        char *zOuter = 0;
        pTab->pNext = p->pTable;
        p->pTable = pTab;

        /* The statement the vtab will pass to sqlite3_declare_vtab() */
        zInner = idxAppendText(&rc, 0, "CREATE TABLE x(");
        for(i=0; i<pTab->nCol; i++){
          zInner = idxAppendText(&rc, zInner, "%s%Q COLLATE %s", 
              (i==0 ? "" : ", "), pTab->aCol[i].zName, pTab->aCol[i].zColl
          );
        }
        zInner = idxAppendText(&rc, zInner, ")");

        /* The CVT statement to create the vtab */
        zOuter = idxAppendText(&rc, 0, 
            "CREATE VIRTUAL TABLE %Q USING expert(%Q)", zName, zInner
        );
        if( rc==SQLITE_OK ){
          rc = sqlite3_exec(p->dbv, zOuter, 0, 0, pzErrmsg);
        }
        sqlite3_free(zInner);
        sqlite3_free(zOuter);
      }
    }
  }
  idxFinalize(&rc, pSchema);
  return rc;
}

struct IdxSampleCtx {
  int iTarget;
  double target;                  /* Target nRet/nRow value */
  double nRow;                    /* Number of rows seen */
  double nRet;                    /* Number of rows returned */
};

static void idxSampleFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  struct IdxSampleCtx *p = (struct IdxSampleCtx*)sqlite3_user_data(pCtx);
  int bRet;

  (void)argv;
  assert( argc==0 );
  if( p->nRow==0.0 ){
    bRet = 1;
  }else{
    bRet = (p->nRet / p->nRow) <= p->target;
    if( bRet==0 ){
      unsigned short rnd;
      sqlite3_randomness(2, (void*)&rnd);
      bRet = ((int)rnd % 100) <= p->iTarget;
    }
  }

  sqlite3_result_int(pCtx, bRet);
  p->nRow += 1.0;
  p->nRet += (double)bRet;
}

struct IdxRemCtx {
  int nSlot;
  struct IdxRemSlot {
    int eType;                    /* SQLITE_NULL, INTEGER, REAL, TEXT, BLOB */
    i64 iVal;                     /* SQLITE_INTEGER value */
    double rVal;                  /* SQLITE_FLOAT value */
    i64 nByte;                    /* Bytes of space allocated at z */
    i64 n;                        /* Size of buffer z */
    char *z;                      /* SQLITE_TEXT/BLOB value */
  } aSlot[1];
};

/*
** Implementation of scalar function sqlite_expert_rem().
*/
static void idxRemFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  struct IdxRemCtx *p = (struct IdxRemCtx*)sqlite3_user_data(pCtx);
  struct IdxRemSlot *pSlot;
  int iSlot;
  assert( argc==2 );

  iSlot = sqlite3_value_int(argv[0]);
  assert( iSlot<p->nSlot );
  pSlot = &p->aSlot[iSlot];

  switch( pSlot->eType ){
    case SQLITE_NULL:
      /* no-op */
      break;

    case SQLITE_INTEGER:
      sqlite3_result_int64(pCtx, pSlot->iVal);
      break;

    case SQLITE_FLOAT:
      sqlite3_result_double(pCtx, pSlot->rVal);
      break;

    case SQLITE_BLOB:
      assert( pSlot->n <= 0x7fffffff );
      sqlite3_result_blob(pCtx, pSlot->z, (int)pSlot->n, SQLITE_TRANSIENT);
      break;

    case SQLITE_TEXT:
      assert( pSlot->n <= 0x7fffffff );
      sqlite3_result_text(pCtx, pSlot->z, (int)pSlot->n, SQLITE_TRANSIENT);
      break;
  }

  pSlot->eType = sqlite3_value_type(argv[1]);
  switch( pSlot->eType ){
    case SQLITE_NULL:
      /* no-op */
      break;

    case SQLITE_INTEGER:
      pSlot->iVal = sqlite3_value_int64(argv[1]);
      break;

    case SQLITE_FLOAT:
      pSlot->rVal = sqlite3_value_double(argv[1]);
      break;

    case SQLITE_BLOB:
    case SQLITE_TEXT: {
      i64 nByte = sqlite3_value_bytes(argv[1]);
      const void *pData = 0;
      if( nByte>pSlot->nByte ){
        char *zNew = (char*)sqlite3_realloc64(pSlot->z, nByte*2);
        if( zNew==0 ){
          sqlite3_result_error_nomem(pCtx);
          return;
        }
        pSlot->nByte = nByte*2;
        pSlot->z = zNew;
      }
      pSlot->n = nByte;
      if( pSlot->eType==SQLITE_BLOB ){
        pData = sqlite3_value_blob(argv[1]);
        if( pData ) memcpy(pSlot->z, pData, nByte);
      }else{
        pData = sqlite3_value_text(argv[1]);
        memcpy(pSlot->z, pData, nByte);
      }
      break;
    }
  }
}

static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
  int rc = SQLITE_OK;
  const char *zMax = 
    "SELECT max(i.seqno) FROM "
    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l, "
    "  pragma_index_info(l.name) AS i "
    "WHERE s.type = 'table'";
  sqlite3_stmt *pMax = 0;

  *pnMax = 0;
  rc = idxPrepareStmt(db, &pMax, pzErr, zMax);
  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
    *pnMax = sqlite3_column_int(pMax, 0) + 1;
  }
  idxFinalize(&rc, pMax);

  return rc;
}

static int idxPopulateOneStat1(
  sqlite3expert *p,
  sqlite3_stmt *pIndexXInfo,
  sqlite3_stmt *pWriteStat,
  const char *zTab,
  const char *zIdx,
  char **pzErr
){
  char *zCols = 0;
  char *zOrder = 0;
  char *zQuery = 0;
  int nCol = 0;
  int i;
  sqlite3_stmt *pQuery = 0;
  i64 *aStat = 0;
  int rc = SQLITE_OK;

  assert( p->iSample>0 );

  /* Formulate the query text */
  sqlite3_bind_text(pIndexXInfo, 1, zIdx, -1, SQLITE_STATIC);
  while( SQLITE_OK==rc && SQLITE_ROW==sqlite3_step(pIndexXInfo) ){
    const char *zComma = zCols==0 ? "" : ", ";
    const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0);
    const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1);
    if( zName==0 ){
      /* This index contains an expression. Ignore it. */
      sqlite3_free(zCols);
      sqlite3_free(zOrder);
      return sqlite3_reset(pIndexXInfo);
    }
    zCols = idxAppendText(&rc, zCols, 
        "%sx.%Q IS sqlite_expert_rem(%d, x.%Q) COLLATE %s", 
        zComma, zName, nCol, zName, zColl
    );
    zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol);
  }
  sqlite3_reset(pIndexXInfo);
  if( rc==SQLITE_OK ){
    if( p->iSample==100 ){
      zQuery = sqlite3_mprintf(
          "SELECT %s FROM %Q x ORDER BY %s", zCols, zTab, zOrder
      );
    }else{
      zQuery = sqlite3_mprintf(
          "SELECT %s FROM temp."UNIQUE_TABLE_NAME" x ORDER BY %s", zCols, zOrder
      );
    }
  }
  sqlite3_free(zCols);
  sqlite3_free(zOrder);

  /* Formulate the query text */
  if( rc==SQLITE_OK ){
    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
    rc = idxPrepareStmt(dbrem, &pQuery, pzErr, zQuery);
  }
  sqlite3_free(zQuery);

  if( rc==SQLITE_OK ){
    aStat = (i64*)idxMalloc(&rc, sizeof(i64)*(nCol+1));
  }
  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
    IdxHashEntry *pEntry;
    char *zStat = 0;
    for(i=0; i<=nCol; i++) aStat[i] = 1;
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
      aStat[0]++;
      for(i=0; i<nCol; i++){
        if( sqlite3_column_int(pQuery, i)==0 ) break;
      }
      for(/*no-op*/; i<nCol; i++){
        aStat[i+1]++;
      }
    }

    if( rc==SQLITE_OK ){
      i64 s0 = aStat[0];
      zStat = sqlite3_mprintf("%lld", s0);
      if( zStat==0 ) rc = SQLITE_NOMEM;
      for(i=1; rc==SQLITE_OK && i<=nCol; i++){
        zStat = idxAppendText(&rc, zStat, " %lld", (s0+aStat[i]/2) / aStat[i]);
      }
    }

    if( rc==SQLITE_OK ){
      sqlite3_bind_text(pWriteStat, 1, zTab, -1, SQLITE_STATIC);
      sqlite3_bind_text(pWriteStat, 2, zIdx, -1, SQLITE_STATIC);
      sqlite3_bind_text(pWriteStat, 3, zStat, -1, SQLITE_STATIC);
      sqlite3_step(pWriteStat);
      rc = sqlite3_reset(pWriteStat);
    }

    pEntry = idxHashFind(&p->hIdx, zIdx, STRLEN(zIdx));
    if( pEntry ){
      assert( pEntry->zVal2==0 );
      pEntry->zVal2 = zStat;
    }else{
      sqlite3_free(zStat);
    }
  }
  sqlite3_free(aStat);
  idxFinalize(&rc, pQuery);

  return rc;
}

static int idxBuildSampleTable(sqlite3expert *p, const char *zTab){
  int rc;
  char *zSql;

  rc = sqlite3_exec(p->dbv,"DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  if( rc!=SQLITE_OK ) return rc;

  zSql = sqlite3_mprintf(
      "CREATE TABLE temp." UNIQUE_TABLE_NAME " AS SELECT * FROM %Q", zTab
  );
  if( zSql==0 ) return SQLITE_NOMEM;
  rc = sqlite3_exec(p->dbv, zSql, 0, 0, 0);
  sqlite3_free(zSql);

  return rc;
}

/*
** This function is called as part of sqlite3_expert_analyze(). Candidate
** indexes have already been created in database sqlite3expert.dbm, this
** function populates sqlite_stat1 table in the same database.
**
** The stat1 data is generated by querying the 
*/
static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
  int rc = SQLITE_OK;
  int nMax =0;
  struct IdxRemCtx *pCtx = 0;
  struct IdxSampleCtx samplectx; 
  int i;
  i64 iPrev = -100000;
  sqlite3_stmt *pAllIndex = 0;
  sqlite3_stmt *pIndexXInfo = 0;
  sqlite3_stmt *pWrite = 0;

  const char *zAllIndex =
    "SELECT s.rowid, s.name, l.name FROM "
    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l "
    "WHERE s.type = 'table'";
  const char *zIndexXInfo = 
    "SELECT name, coll FROM pragma_index_xinfo(?) WHERE key";
  const char *zWrite = "INSERT INTO sqlite_stat1 VALUES(?, ?, ?)";

  /* If iSample==0, no sqlite_stat1 data is required. */
  if( p->iSample==0 ) return SQLITE_OK;

  rc = idxLargestIndex(p->dbm, &nMax, pzErr);
  if( nMax<=0 || rc!=SQLITE_OK ) return rc;

  rc = sqlite3_exec(p->dbm, "ANALYZE; PRAGMA writable_schema=1", 0, 0, 0);

  if( rc==SQLITE_OK ){
    i64 nByte = sizeof(struct IdxRemCtx) + (sizeof(struct IdxRemSlot) * nMax);
    pCtx = (struct IdxRemCtx*)idxMalloc(&rc, nByte);
  }

  if( rc==SQLITE_OK ){
    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
    rc = sqlite3_create_function(dbrem, "sqlite_expert_rem", 
        2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
    );
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(p->db, "sqlite_expert_sample", 
        0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
    );
  }

  if( rc==SQLITE_OK ){
    pCtx->nSlot = (i64)nMax+1;
    rc = idxPrepareStmt(p->dbm, &pAllIndex, pzErr, zAllIndex);
  }
  if( rc==SQLITE_OK ){
    rc = idxPrepareStmt(p->dbm, &pIndexXInfo, pzErr, zIndexXInfo);
  }
  if( rc==SQLITE_OK ){
    rc = idxPrepareStmt(p->dbm, &pWrite, pzErr, zWrite);
  }

  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pAllIndex) ){
    i64 iRowid = sqlite3_column_int64(pAllIndex, 0);
    const char *zTab = (const char*)sqlite3_column_text(pAllIndex, 1);
    const char *zIdx = (const char*)sqlite3_column_text(pAllIndex, 2);
    if( zTab==0 || zIdx==0 ) continue;
    if( p->iSample<100 && iPrev!=iRowid ){
      samplectx.target = (double)p->iSample / 100.0;
      samplectx.iTarget = p->iSample;
      samplectx.nRow = 0.0;
      samplectx.nRet = 0.0;
      rc = idxBuildSampleTable(p, zTab);
      if( rc!=SQLITE_OK ) break;
    }
    rc = idxPopulateOneStat1(p, pIndexXInfo, pWrite, zTab, zIdx, pzErr);
    iPrev = iRowid;
  }
  if( rc==SQLITE_OK && p->iSample<100 ){
    rc = sqlite3_exec(p->dbv, 
        "DROP TABLE IF EXISTS temp." UNIQUE_TABLE_NAME, 0,0,0
    );
  }

  idxFinalize(&rc, pAllIndex);
  idxFinalize(&rc, pIndexXInfo);
  idxFinalize(&rc, pWrite);

  if( pCtx ){
    for(i=0; i<pCtx->nSlot; i++){
      sqlite3_free(pCtx->aSlot[i].z);
    }
    sqlite3_free(pCtx);
  }

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
  }

  sqlite3_create_function(p->db, "sqlite_expert_rem", 2, SQLITE_UTF8, 0,0,0,0);
  sqlite3_create_function(p->db, "sqlite_expert_sample", 0,SQLITE_UTF8,0,0,0,0);

  sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  return rc;
}

/*
** Define and possibly pretend to use a useless collation sequence.
** This pretense allows expert to accept SQL using custom collations.
*/
int dummyCompare(void *up1, int up2, const void *up3, int up4, const void *up5){
  (void)up1;
  (void)up2;
  (void)up3;
  (void)up4;
  (void)up5;
  assert(0); /* VDBE should never be run. */
  return 0;
}
/* And a callback to register above upon actual need */
void useDummyCS(void *up1, sqlite3 *db, int etr, const char *zName){
  (void)up1;
  sqlite3_create_collation_v2(db, zName, etr, 0, dummyCompare, 0);
}

#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) \
  && !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
/*
** dummy functions for no-op implementation of UDFs during expert's work
*/
void dummyUDF(sqlite3_context *up1, int up2, sqlite3_value **up3){
  (void)up1;
  (void)up2;
  (void)up3;
  assert(0); /* VDBE should never be run. */
}
void dummyUDFvalue(sqlite3_context *up1){
  (void)up1;
  assert(0); /* VDBE should never be run. */
}

/*
** Register UDFs from user database with another.
*/
int registerUDFs(sqlite3 *dbSrc, sqlite3 *dbDst){
  sqlite3_stmt *pStmt;
  int rc = sqlite3_prepare_v2(dbSrc,
            "SELECT name,type,enc,narg,flags "
            "FROM pragma_function_list() "
            "WHERE builtin==0", -1, &pStmt, 0);
  if( rc==SQLITE_OK ){
    while( SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
      int nargs = sqlite3_column_int(pStmt,3);
      int flags = sqlite3_column_int(pStmt,4);
      const char *name = (char*)sqlite3_column_text(pStmt,0);
      const char *type = (char*)sqlite3_column_text(pStmt,1);
      const char *enc = (char*)sqlite3_column_text(pStmt,2);
      if( name==0 || type==0 || enc==0 ){
        /* no-op.  Only happens on OOM */
      }else{
        int ienc = SQLITE_UTF8;
        int rcf = SQLITE_ERROR;
        if( strcmp(enc,"utf16le")==0 ) ienc = SQLITE_UTF16LE;
        else if( strcmp(enc,"utf16be")==0 ) ienc = SQLITE_UTF16BE;
        ienc |= (flags & (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY));
        if( strcmp(type,"w")==0 ){
          rcf = sqlite3_create_window_function(dbDst,name,nargs,ienc,0,
                                               dummyUDF,dummyUDFvalue,0,0,0);
        }else if( strcmp(type,"a")==0 ){
          rcf = sqlite3_create_function(dbDst,name,nargs,ienc,0,
                                        0,dummyUDF,dummyUDFvalue);
        }else if( strcmp(type,"s")==0 ){
          rcf = sqlite3_create_function(dbDst,name,nargs,ienc,0,
                                        dummyUDF,0,0);
        }
        if( rcf!=SQLITE_OK ){
          rc = rcf;
          break;
        }
      }
    }
    sqlite3_finalize(pStmt);
    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
  }
  return rc;
}
#endif

/*
** Allocate a new sqlite3expert object.
*/
sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
  int rc = SQLITE_OK;
  sqlite3expert *pNew;

  pNew = (sqlite3expert*)idxMalloc(&rc, sizeof(sqlite3expert));

  /* Open two in-memory databases to work with. The "vtab database" (dbv)
  ** will contain a virtual table corresponding to each real table in
  ** the user database schema, and a copy of each view. It is used to
  ** collect information regarding the WHERE, ORDER BY and other clauses
  ** of the user's query.
  */
  if( rc==SQLITE_OK ){
    pNew->db = db;
    pNew->iSample = 100;
    rc = sqlite3_open(":memory:", &pNew->dbv);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_open(":memory:", &pNew->dbm);
    if( rc==SQLITE_OK ){
      sqlite3_db_config(pNew->dbm, SQLITE_DBCONFIG_TRIGGER_EQP, 1, (int*)0);
    }
  }

  /* Allow custom collations to be dealt with through prepare. */
  if( rc==SQLITE_OK ) rc = sqlite3_collation_needed(pNew->dbm,0,useDummyCS);
  if( rc==SQLITE_OK ) rc = sqlite3_collation_needed(pNew->dbv,0,useDummyCS);

#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) \
  && !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
  /* Register UDFs from database [db] with [dbm] and [dbv]. */
  if( rc==SQLITE_OK ){
    rc = registerUDFs(pNew->db, pNew->dbm);
  }
  if( rc==SQLITE_OK ){
    rc = registerUDFs(pNew->db, pNew->dbv);
  }
#endif

  /* Copy the entire schema of database [db] into [dbm]. */
  if( rc==SQLITE_OK ){
    sqlite3_stmt *pSql = 0;
    rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg, 
        "SELECT sql, name, substr(sql,1,14)=='create virtual' COLLATE nocase"
        " FROM sqlite_schema WHERE substr(name,1,7)!='sqlite_' COLLATE nocase"
        " ORDER BY 3 DESC, rowid"
    );
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
      const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
      const char *zName = (const char*)sqlite3_column_text(pSql, 1);
      int bExists = 0;
      rc = expertDbContainsObject(pNew->dbm, zName, &bExists);
      if( rc==SQLITE_OK && zSql && bExists==0 ){
        rc = expertSchemaSql(pNew->dbm, zSql, pzErrmsg);
      }
    }
    idxFinalize(&rc, pSql);
  }

  /* Create the vtab schema */
  if( rc==SQLITE_OK ){
    rc = idxCreateVtabSchema(pNew, pzErrmsg);
  }

  /* Register the auth callback with dbv */
  if( rc==SQLITE_OK ){
    sqlite3_set_authorizer(pNew->dbv, idxAuthCallback, (void*)pNew);
  }

  /* If an error has occurred, free the new object and return NULL. Otherwise,
  ** return the new sqlite3expert handle.  */
  if( rc!=SQLITE_OK ){
    sqlite3_expert_destroy(pNew);
    pNew = 0;
  }
  return pNew;
}

/*
** Configure an sqlite3expert object.
*/
int sqlite3_expert_config(sqlite3expert *p, int op, ...){
  int rc = SQLITE_OK;
  va_list ap;
  va_start(ap, op);
  switch( op ){
    case EXPERT_CONFIG_SAMPLE: {
      int iVal = va_arg(ap, int);
      if( iVal<0 ) iVal = 0;
      if( iVal>100 ) iVal = 100;
      p->iSample = iVal;
      break;
    }
    default:
      rc = SQLITE_NOTFOUND;
      break;
  }

  va_end(ap);
  return rc;
}

/*
** Add an SQL statement to the analysis.
*/
int sqlite3_expert_sql(
  sqlite3expert *p,               /* From sqlite3_expert_new() */
  const char *zSql,               /* SQL statement to add */
  char **pzErr                    /* OUT: Error message (if any) */
){
  IdxScan *pScanOrig = p->pScan;
  IdxStatement *pStmtOrig = p->pStatement;
  int rc = SQLITE_OK;
  const char *zStmt = zSql;

  if( p->bRun ) return SQLITE_MISUSE;

  while( rc==SQLITE_OK && zStmt && zStmt[0] ){
    sqlite3_stmt *pStmt = 0;
    /* Ensure that the provided statement compiles against user's DB. */
    rc = idxPrepareStmt(p->db, &pStmt, pzErr, zStmt);
    if( rc!=SQLITE_OK ) break;
    sqlite3_finalize(pStmt);
    rc = sqlite3_prepare_v2(p->dbv, zStmt, -1, &pStmt, &zStmt);
    if( rc==SQLITE_OK ){
      if( pStmt ){
        IdxStatement *pNew;
        const char *z = sqlite3_sql(pStmt);
        i64 n = STRLEN(z);
        pNew = (IdxStatement*)idxMalloc(&rc, sizeof(IdxStatement) + n+1);
        if( rc==SQLITE_OK ){
          pNew->zSql = (char*)&pNew[1];
          memcpy(pNew->zSql, z, n+1);
          pNew->pNext = p->pStatement;
          if( p->pStatement ) pNew->iId = p->pStatement->iId+1;
          p->pStatement = pNew;
        }
        sqlite3_finalize(pStmt);
      }
    }else{
      idxDatabaseError(p->dbv, pzErr);
    }
  }

  if( rc!=SQLITE_OK ){
    idxScanFree(p->pScan, pScanOrig);
    idxStatementFree(p->pStatement, pStmtOrig);
    p->pScan = pScanOrig;
    p->pStatement = pStmtOrig;
  }

  return rc;
}

int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr){
  int rc;
  IdxHashEntry *pEntry;

  /* Do trigger processing to collect any extra IdxScan structures */
  rc = idxProcessTriggers(p, pzErr);

  /* Create candidate indexes within the in-memory database file */
  if( rc==SQLITE_OK ){
    rc = idxCreateCandidates(p);
  }else if ( rc==SQLITE_BUSY_TIMEOUT ){
    if( pzErr )
      *pzErr = sqlite3_mprintf("Cannot find a unique index name to propose.");
    return rc;
  }

  /* Generate the stat1 data */
  if( rc==SQLITE_OK ){
    rc = idxPopulateStat1(p, pzErr);
  }

  /* Formulate the EXPERT_REPORT_CANDIDATES text */
  for(pEntry=p->hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
    p->zCandidates = idxAppendText(&rc, p->zCandidates, 
        "%s;%s%s\n", pEntry->zVal, 
        pEntry->zVal2 ? " -- stat1: " : "", pEntry->zVal2
    );
  }

  /* Figure out which of the candidate indexes are preferred by the query
  ** planner and report the results to the user.  */
  if( rc==SQLITE_OK ){
    rc = idxFindIndexes(p, pzErr);
  }

  if( rc==SQLITE_OK ){
    p->bRun = 1;
  }
  return rc;
}

/*
** Return the total number of statements that have been added to this
** sqlite3expert using sqlite3_expert_sql().
*/
int sqlite3_expert_count(sqlite3expert *p){
  int nRet = 0;
  if( p->pStatement ) nRet = p->pStatement->iId+1;
  return nRet;
}

/*
** Return a component of the report.
*/
const char *sqlite3_expert_report(sqlite3expert *p, int iStmt, int eReport){
  const char *zRet = 0;
  IdxStatement *pStmt;

  if( p->bRun==0 ) return 0;
  for(pStmt=p->pStatement; pStmt && pStmt->iId!=iStmt; pStmt=pStmt->pNext);
  switch( eReport ){
    case EXPERT_REPORT_SQL:
      if( pStmt ) zRet = pStmt->zSql;
      break;
    case EXPERT_REPORT_INDEXES:
      if( pStmt ) zRet = pStmt->zIdx;
      break;
    case EXPERT_REPORT_PLAN:
      if( pStmt ) zRet = pStmt->zEQP;
      break;
    case EXPERT_REPORT_CANDIDATES:
      zRet = p->zCandidates;
      break;
  }
  return zRet;
}

/*
** Free an sqlite3expert object.
*/
void sqlite3_expert_destroy(sqlite3expert *p){
  if( p ){
    sqlite3_close(p->dbm);
    sqlite3_close(p->dbv);
    idxScanFree(p->pScan, 0);
    idxStatementFree(p->pStatement, 0);
    idxTableFree(p->pTable);
    idxWriteFree(p->pWrite);
    idxHashClear(&p->hIdx);
    sqlite3_free(p->zCandidates);
    sqlite3_free(p);
  }
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/************************* End ext/expert/sqlite3expert.c ********************/
#endif
/************************* Begin ext/intck/sqlite3intck.h ******************/
/*
** 2024-02-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

/*
** Incremental Integrity-Check Extension
** -------------------------------------
**
** This module contains code to check whether or not an SQLite database
** is well-formed or corrupt. This is the same task as performed by SQLite's
** built-in "PRAGMA integrity_check" command. This module differs from
** "PRAGMA integrity_check" in that:
**
**   +  It is less thorough - this module does not detect certain types
**      of corruption that are detected by the PRAGMA command. However,
**      it does detect all kinds of corruption that are likely to cause
**      errors in SQLite applications.
**
**   +  It is slower. Sometimes up to three times slower.
**
**   +  It allows integrity-check operations to be split into multiple
**      transactions, so that the database does not need to be read-locked
**      for the duration of the integrity-check.
**
** One way to use the API to run integrity-check on the "main" database
** of handle db is:
**
**   int rc = SQLITE_OK;
**   sqlite3_intck *p = 0;
**
**   sqlite3_intck_open(db, "main", &p);
**   while( SQLITE_OK==sqlite3_intck_step(p) ){
**     const char *zMsg = sqlite3_intck_message(p);
**     if( zMsg ) printf("corruption: %s\n", zMsg);
**   }
**   rc = sqlite3_intck_error(p, &zErr);
**   if( rc!=SQLITE_OK ){
**     printf("error occured (rc=%d), (errmsg=%s)\n", rc, zErr);
**   }
**   sqlite3_intck_close(p);
**
** Usually, the sqlite3_intck object opens a read transaction within the
** first call to sqlite3_intck_step() and holds it open until the 
** integrity-check is complete. However, if sqlite3_intck_unlock() is
** called, the read transaction is ended and a new read transaction opened
** by the subsequent call to sqlite3_intck_step().
*/

#ifndef _SQLITE_INTCK_H
#define _SQLITE_INTCK_H

/* #include "sqlite3.h" */

#ifdef __cplusplus
extern "C" {
#endif

/*
** An ongoing incremental integrity-check operation is represented by an
** opaque pointer of the following type.
*/
typedef struct sqlite3_intck sqlite3_intck;

/*
** Open a new incremental integrity-check object. If successful, populate
** output variable (*ppOut) with the new object handle and return SQLITE_OK.
** Or, if an error occurs, set (*ppOut) to NULL and return an SQLite error
** code (e.g. SQLITE_NOMEM).
**
** The integrity-check will be conducted on database zDb (which must be "main",
** "temp", or the name of an attached database) of database handle db. Once
** this function has been called successfully, the caller should not use 
** database handle db until the integrity-check object has been destroyed
** using sqlite3_intck_close().
*/
int sqlite3_intck_open(
  sqlite3 *db,                    /* Database handle */
  const char *zDb,                /* Database name ("main", "temp" etc.) */
  sqlite3_intck **ppOut           /* OUT: New sqlite3_intck handle */
);

/*
** Close and release all resources associated with a handle opened by an
** earlier call to sqlite3_intck_open(). The results of using an
** integrity-check handle after it has been passed to this function are
** undefined.
*/
void sqlite3_intck_close(sqlite3_intck *pCk);

/*
** Do the next step of the integrity-check operation specified by the handle
** passed as the only argument. This function returns SQLITE_DONE if the 
** integrity-check operation is finished, or an SQLite error code if
** an error occurs, or SQLITE_OK if no error occurs but the integrity-check
** is not finished. It is not considered an error if database corruption
** is encountered.
**
** Following a successful call to sqlite3_intck_step() (one that returns
** SQLITE_OK), sqlite3_intck_message() returns a non-NULL value if 
** corruption was detected in the db.
**
** If an error occurs and a value other than SQLITE_OK or SQLITE_DONE is
** returned, then the integrity-check handle is placed in an error state.
** In this state all subsequent calls to sqlite3_intck_step() or 
** sqlite3_intck_unlock() will immediately return the same error. The 
** sqlite3_intck_error() method may be used to obtain an English language 
** error message in this case.
*/
int sqlite3_intck_step(sqlite3_intck *pCk);

/*
** If the previous call to sqlite3_intck_step() encountered corruption 
** within the database, then this function returns a pointer to a buffer
** containing a nul-terminated string describing the corruption in 
** English. If the previous call to sqlite3_intck_step() did not encounter
** corruption, or if there was no previous call, this function returns 
** NULL.
*/
const char *sqlite3_intck_message(sqlite3_intck *pCk);

/*
** Close any read-transaction opened by an earlier call to 
** sqlite3_intck_step(). Any subsequent call to sqlite3_intck_step() will
** open a new transaction. Return SQLITE_OK if successful, or an SQLite error
** code otherwise.
**
** If an error occurs, then the integrity-check handle is placed in an error
** state. In this state all subsequent calls to sqlite3_intck_step() or 
** sqlite3_intck_unlock() will immediately return the same error. The 
** sqlite3_intck_error() method may be used to obtain an English language 
** error message in this case.
*/
int sqlite3_intck_unlock(sqlite3_intck *pCk);

/*
** If an error has occurred in an earlier call to sqlite3_intck_step()
** or sqlite3_intck_unlock(), then this method returns the associated 
** SQLite error code. Additionally, if pzErr is not NULL, then (*pzErr)
** may be set to point to a nul-terminated string containing an English
** language error message. Or, if no error message is available, to
** NULL.
**
** If no error has occurred within sqlite3_intck_step() or
** sqlite_intck_unlock() calls on the handle passed as the first argument, 
** then SQLITE_OK is returned and (*pzErr) set to NULL.
*/
int sqlite3_intck_error(sqlite3_intck *pCk, const char **pzErr);

/*
** This API is used for testing only. It returns the full-text of an SQL
** statement used to test object zObj, which may be a table or index.
** The returned buffer is valid until the next call to either this function
** or sqlite3_intck_close() on the same sqlite3_intck handle.
*/
const char *sqlite3_intck_test_sql(sqlite3_intck *pCk, const char *zObj);


#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif /* ifndef _SQLITE_INTCK_H */

/************************* End ext/intck/sqlite3intck.h ********************/
/************************* Begin ext/intck/sqlite3intck.c ******************/
/*
** 2024-02-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

/* #include "sqlite3intck.h" */
#include <string.h>
#include <assert.h>

#include <stdio.h>
#include <stdlib.h>

/*
** nKeyVal:
**   The number of values that make up the 'key' for the current pCheck
**   statement.
**
** rc:
**   Error code returned by most recent sqlite3_intck_step() or 
**   sqlite3_intck_unlock() call. This is set to SQLITE_DONE when
**   the integrity-check operation is finished.
**
** zErr:
**   If the object has entered the error state, this is the error message.
**   Is freed using sqlite3_free() when the object is deleted.
**
** zTestSql:
**   The value returned by the most recent call to sqlite3_intck_testsql().
**   Each call to testsql() frees the previous zTestSql value (using
**   sqlite3_free()) and replaces it with the new value it will return.
*/
struct sqlite3_intck {
  sqlite3 *db;
  const char *zDb;                /* Copy of zDb parameter to _open() */
  char *zObj;                     /* Current object. Or NULL. */

  sqlite3_stmt *pCheck;           /* Current check statement */
  char *zKey;
  int nKeyVal;

  char *zMessage;
  int bCorruptSchema;

  int rc;                         /* Error code */
  char *zErr;                     /* Error message */
  char *zTestSql;                 /* Returned by sqlite3_intck_test_sql() */
};


/*
** Some error has occurred while using database p->db. Save the error message
** and error code currently held by the database handle in p->rc and p->zErr.
*/
static void intckSaveErrmsg(sqlite3_intck *p){
  p->rc = sqlite3_errcode(p->db);
  sqlite3_free(p->zErr);
  p->zErr = sqlite3_mprintf("%s", sqlite3_errmsg(p->db));
}

/*
** If the handle passed as the first argument is already in the error state,
** then this function is a no-op (returns NULL immediately). Otherwise, if an
** error occurs within this function, it leaves an error in said handle.
**
** Otherwise, this function attempts to prepare SQL statement zSql and
** return the resulting statement handle to the user.
*/
static sqlite3_stmt *intckPrepare(sqlite3_intck *p, const char *zSql){
  sqlite3_stmt *pRet = 0;
  if( p->rc==SQLITE_OK ){
    p->rc = sqlite3_prepare_v2(p->db, zSql, -1, &pRet, 0);
    if( p->rc!=SQLITE_OK ){
      intckSaveErrmsg(p);
      assert( pRet==0 );
    }
  }
  return pRet;
}

/*
** If the handle passed as the first argument is already in the error state,
** then this function is a no-op (returns NULL immediately). Otherwise, if an
** error occurs within this function, it leaves an error in said handle.
**
** Otherwise, this function treats argument zFmt as a printf() style format
** string. It formats it according to the trailing arguments and then 
** attempts to prepare the results and return the resulting prepared
** statement.
*/
static sqlite3_stmt *intckPrepareFmt(sqlite3_intck *p, const char *zFmt, ...){
  sqlite3_stmt *pRet = 0;
  va_list ap;
  char *zSql = 0;
  va_start(ap, zFmt);
  zSql = sqlite3_vmprintf(zFmt, ap);
  if( p->rc==SQLITE_OK && zSql==0 ){
    p->rc = SQLITE_NOMEM;
  }
  pRet = intckPrepare(p, zSql);
  sqlite3_free(zSql);
  va_end(ap);
  return pRet;
}

/*
** Finalize SQL statement pStmt. If an error occurs and the handle passed
** as the first argument does not already contain an error, store the
** error in the handle.
*/
static void intckFinalize(sqlite3_intck *p, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( p->rc==SQLITE_OK && rc!=SQLITE_OK ){
    intckSaveErrmsg(p);
  }
}

/*
** If there is already an error in handle p, return it. Otherwise, call
** sqlite3_step() on the statement handle and return that value.
*/
static int intckStep(sqlite3_intck *p, sqlite3_stmt *pStmt){
  if( p->rc ) return p->rc;
  return sqlite3_step(pStmt);
}

/*
** Execute SQL statement zSql. There is no way to obtain any results 
** returned by the statement. This function uses the sqlite3_intck error
** code convention.
*/
static void intckExec(sqlite3_intck *p, const char *zSql){
  sqlite3_stmt *pStmt = 0;
  pStmt = intckPrepare(p, zSql);
  intckStep(p, pStmt);
  intckFinalize(p, pStmt);
}

/*
** A wrapper around sqlite3_mprintf() that uses the sqlite3_intck error
** code convention.
*/
static char *intckMprintf(sqlite3_intck *p, const char *zFmt, ...){
  va_list ap;
  char *zRet = 0;
  va_start(ap, zFmt);
  zRet = sqlite3_vmprintf(zFmt, ap);
  if( p->rc==SQLITE_OK ){
    if( zRet==0 ){
      p->rc = SQLITE_NOMEM;
    }
  }else{
    sqlite3_free(zRet);
    zRet = 0;
  }
  va_end(ap);
  return zRet;
}

/*
** This is used by sqlite3_intck_unlock() to save the vector key value 
** required to restart the current pCheck query as a nul-terminated string 
** in p->zKey.
*/
static void intckSaveKey(sqlite3_intck *p){
  int ii;
  char *zSql = 0;
  sqlite3_stmt *pStmt = 0;
  sqlite3_stmt *pXinfo = 0;
  const char *zDir = 0;

  assert( p->pCheck );
  assert( p->zKey==0 );

  pXinfo = intckPrepareFmt(p, 
      "SELECT group_concat(desc, '') FROM %Q.sqlite_schema s, "
      "pragma_index_xinfo(%Q, %Q) "
      "WHERE s.type='index' AND s.name=%Q",
      p->zDb, p->zObj, p->zDb, p->zObj
  );
  if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXinfo) ){
    zDir = (const char*)sqlite3_column_text(pXinfo, 0);
  }

  if( zDir==0 ){
    /* Object is a table, not an index. This is the easy case,as there are 
    ** no DESC columns or NULL values in a primary key.  */
    const char *zSep = "SELECT '(' || ";
    for(ii=0; ii<p->nKeyVal; ii++){
      zSql = intckMprintf(p, "%z%squote(?)", zSql, zSep);
      zSep = " || ', ' || ";
    }
    zSql = intckMprintf(p, "%z || ')'", zSql);
  }else{

    /* Object is an index. */
    assert( p->nKeyVal>1 );
    for(ii=p->nKeyVal; ii>0; ii--){
      int bLastIsDesc = zDir[ii-1]=='1';
      int bLastIsNull = sqlite3_column_type(p->pCheck, ii)==SQLITE_NULL;
      const char *zLast = sqlite3_column_name(p->pCheck, ii);
      char *zLhs = 0;
      char *zRhs = 0;
      char *zWhere = 0;

      if( bLastIsNull ){
        if( bLastIsDesc ) continue;
        zWhere = intckMprintf(p, "'%s IS NOT NULL'", zLast);
      }else{
        const char *zOp = bLastIsDesc ? "<" : ">";
        zWhere = intckMprintf(p, "'%s %s ' || quote(?%d)", zLast, zOp, ii);
      }

      if( ii>1 ){
        const char *zLhsSep = "";
        const char *zRhsSep = "";
        int jj;
        for(jj=0; jj<ii-1; jj++){
          const char *zAlias = (const char*)sqlite3_column_name(p->pCheck,jj+1);
          zLhs = intckMprintf(p, "%z%s%s", zLhs, zLhsSep, zAlias);
          zRhs = intckMprintf(p, "%z%squote(?%d)", zRhs, zRhsSep, jj+1);
          zLhsSep = ",";
          zRhsSep = " || ',' || ";
        }

        zWhere = intckMprintf(p, 
            "'(%z) IS (' || %z || ') AND ' || %z",
            zLhs, zRhs, zWhere);
      }
      zWhere = intckMprintf(p, "'WHERE ' || %z", zWhere);

      zSql = intckMprintf(p, "%z%s(quote( %z ) )",
          zSql,
          (zSql==0 ? "VALUES" : ",\n      "),
          zWhere
      );
    }
    zSql = intckMprintf(p, 
        "WITH wc(q) AS (\n%z\n)"
        "SELECT 'VALUES' || group_concat('(' || q || ')', ',\n      ') FROM wc"
        , zSql
    );
  }

  pStmt = intckPrepare(p, zSql);
  if( p->rc==SQLITE_OK ){
    for(ii=0; ii<p->nKeyVal; ii++){
      sqlite3_bind_value(pStmt, ii+1, sqlite3_column_value(p->pCheck, ii+1));
    }
    if( SQLITE_ROW==sqlite3_step(pStmt) ){
      p->zKey = intckMprintf(p,"%s",(const char*)sqlite3_column_text(pStmt, 0));
    }
    intckFinalize(p, pStmt);
  }

  sqlite3_free(zSql);
  intckFinalize(p, pXinfo);
}

/*
** Find the next database object (table or index) to check. If successful,
** set sqlite3_intck.zObj to point to a nul-terminated buffer containing
** the object's name before returning.
*/
static void intckFindObject(sqlite3_intck *p){
  sqlite3_stmt *pStmt = 0;
  char *zPrev = p->zObj;
  p->zObj = 0;

  assert( p->rc==SQLITE_OK );
  assert( p->pCheck==0 );

  pStmt = intckPrepareFmt(p, 
    "WITH tables(table_name) AS (" 
    "  SELECT name"
    "  FROM %Q.sqlite_schema WHERE (type='table' OR type='index') AND rootpage"
    "  UNION ALL "
    "  SELECT 'sqlite_schema'"
    ")"
    "SELECT table_name FROM tables "
    "WHERE ?1 IS NULL OR table_name%s?1 "
    "ORDER BY 1"
    , p->zDb, (p->zKey ? ">=" : ">")
  );

  if( p->rc==SQLITE_OK ){
    sqlite3_bind_text(pStmt, 1, zPrev, -1, SQLITE_TRANSIENT);
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      p->zObj = intckMprintf(p,"%s",(const char*)sqlite3_column_text(pStmt, 0));
    }
  }
  intckFinalize(p, pStmt);

  /* If this is a new object, ensure the previous key value is cleared. */
  if( sqlite3_stricmp(p->zObj, zPrev) ){
    sqlite3_free(p->zKey);
    p->zKey = 0;
  }

  sqlite3_free(zPrev);
}

/*
** Return the size in bytes of the first token in nul-terminated buffer z.
** For the purposes of this call, a token is either:
**
**   *  a quoted SQL string,
*    *  a contiguous series of ascii alphabet characters, or
*    *  any other single byte.
*/
static int intckGetToken(const char *z){
  char c = z[0];
  int iRet = 1;
  if( c=='\'' || c=='"' || c=='`' ){
    while( z[iRet] ){
      if( z[iRet]==c ){
        iRet++;
        if( z[iRet]!=c ) break;
      }
      iRet++;
    }
  }
  else if( c=='[' ){
    while( z[iRet++]!=']' && z[iRet] );
  }
  else if( (c>='A' && c<='Z') || (c>='a' && c<='z') ){
    while( (z[iRet]>='A' && z[iRet]<='Z') || (z[iRet]>='a' && z[iRet]<='z') ){
      iRet++;
    }
  }

  return iRet;
}

/*
** Return true if argument c is an ascii whitespace character.
*/
static int intckIsSpace(char c){
  return (c==' ' || c=='\t' || c=='\n' || c=='\r');
}

/*
** Argument z points to the text of a CREATE INDEX statement. This function
** identifies the part of the text that contains either the index WHERE 
** clause (if iCol<0) or the iCol'th column of the index.
**
** If (iCol<0), the identified fragment does not include the "WHERE" keyword,
** only the expression that follows it. If (iCol>=0) then the identified
** fragment does not include any trailing sort-order keywords - "ASC" or 
** "DESC".
**
** If the CREATE INDEX statement does not contain the requested field or
** clause, NULL is returned and (*pnByte) is set to 0. Otherwise, a pointer to
** the identified fragment is returned and output parameter (*pnByte) set
** to its size in bytes.
*/
static const char *intckParseCreateIndex(const char *z, int iCol, int *pnByte){
  int iOff = 0;
  int iThisCol = 0;
  int iStart = 0;
  int nOpen = 0;

  const char *zRet = 0;
  int nRet = 0;

  int iEndOfCol = 0;

  /* Skip forward until the first "(" token */
  while( z[iOff]!='(' ){
    iOff += intckGetToken(&z[iOff]);
    if( z[iOff]=='\0' ) return 0;
  }
  assert( z[iOff]=='(' );

  nOpen = 1;
  iOff++;
  iStart = iOff;
  while( z[iOff] ){
    const char *zToken = &z[iOff];
    int nToken = 0;

    /* Check if this is the end of the current column - either a "," or ")"
    ** when nOpen==1.  */
    if( nOpen==1 ){
      if( z[iOff]==',' || z[iOff]==')' ){
        if( iCol==iThisCol ){
          int iEnd = iEndOfCol ? iEndOfCol : iOff;
          nRet = (iEnd - iStart);
          zRet = &z[iStart];
          break;
        }
        iStart = iOff+1;
        while( intckIsSpace(z[iStart]) ) iStart++;
        iThisCol++;
      }
      if( z[iOff]==')' ) break;
    }
    if( z[iOff]=='(' ) nOpen++;
    if( z[iOff]==')' ) nOpen--;
    nToken = intckGetToken(zToken);

    if( (nToken==3 && 0==sqlite3_strnicmp(zToken, "ASC", nToken))
     || (nToken==4 && 0==sqlite3_strnicmp(zToken, "DESC", nToken))
    ){
      iEndOfCol = iOff;
    }else if( 0==intckIsSpace(zToken[0]) ){
      iEndOfCol = 0;
    }

    iOff += nToken;
  }

  /* iStart is now the byte offset of 1 byte passed the final ')' in the
  ** CREATE INDEX statement. Try to find a WHERE clause to return.  */
  while( zRet==0 && z[iOff] ){
    int n = intckGetToken(&z[iOff]);
    if( n==5 && 0==sqlite3_strnicmp(&z[iOff], "where", 5) ){
      zRet = &z[iOff+5];
      nRet = (int)strlen(zRet);
    }
    iOff += n;
  }

  /* Trim any whitespace from the start and end of the returned string. */
  if( zRet ){
    while( intckIsSpace(zRet[0]) ){
      nRet--;
      zRet++;
    }
    while( nRet>0 && intckIsSpace(zRet[nRet-1]) ) nRet--;
  }

  *pnByte = nRet;
  return zRet;
}

/*
** User-defined SQL function wrapper for intckParseCreateIndex():
**
**     SELECT parse_create_index(<sql>, <icol>);
*/
static void intckParseCreateIndexFunc(
  sqlite3_context *pCtx, 
  int nVal, 
  sqlite3_value **apVal
){
  const char *zSql = (const char*)sqlite3_value_text(apVal[0]);
  int idx = sqlite3_value_int(apVal[1]);
  const char *zRes = 0;
  int nRes = 0;

  assert( nVal==2 );
  if( zSql ){
    zRes = intckParseCreateIndex(zSql, idx, &nRes);
  }
  sqlite3_result_text(pCtx, zRes, nRes, SQLITE_TRANSIENT);
}

/*
** Return true if sqlite3_intck.db has automatic indexes enabled, false
** otherwise.
*/
static int intckGetAutoIndex(sqlite3_intck *p){
  int bRet = 0;
  sqlite3_stmt *pStmt = 0;
  pStmt = intckPrepare(p, "PRAGMA automatic_index");
  if( SQLITE_ROW==intckStep(p, pStmt) ){
    bRet = sqlite3_column_int(pStmt, 0);
  }
  intckFinalize(p, pStmt);
  return bRet;
}

/*
** Return true if zObj is an index, or false otherwise.
*/
static int intckIsIndex(sqlite3_intck *p, const char *zObj){
  int bRet = 0;
  sqlite3_stmt *pStmt = 0;
  pStmt = intckPrepareFmt(p, 
      "SELECT 1 FROM %Q.sqlite_schema WHERE name=%Q AND type='index'",
      p->zDb, zObj
  );
  if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
    bRet = 1;
  }
  intckFinalize(p, pStmt);
  return bRet;
}

/*
** Return a pointer to a nul-terminated buffer containing the SQL statement
** used to check database object zObj (a table or index) for corruption.
** If parameter zPrev is not NULL, then it must be a string containing the
** vector key required to restart the check where it left off last time.
** If pnKeyVal is not NULL, then (*pnKeyVal) is set to the number of
** columns in the vector key value for the specified object.
**
** This function uses the sqlite3_intck error code convention.
*/
static char *intckCheckObjectSql(
  sqlite3_intck *p,               /* Integrity check object */
  const char *zObj,               /* Object (table or index) to scan */
  const char *zPrev,              /* Restart key vector, if any */
  int *pnKeyVal                   /* OUT: Number of key-values for this scan */
){
  char *zRet = 0;
  sqlite3_stmt *pStmt = 0;
  int bAutoIndex = 0;
  int bIsIndex = 0;

  const char *zCommon = 
      /* Relation without_rowid also contains just one row. Column "b" is
      ** set to true if the table being examined is a WITHOUT ROWID table,
      ** or false otherwise.  */
      ", without_rowid(b) AS ("
      "  SELECT EXISTS ("
      "    SELECT 1 FROM tabname, pragma_index_list(tab, db) AS l"
      "      WHERE origin='pk' "
      "      AND NOT EXISTS (SELECT 1 FROM sqlite_schema WHERE name=l.name)"
      "  )"
      ")"
      ""
      /* Table idx_cols contains 1 row for each column in each index on the
      ** table being checked. Columns are:
      **
      **   idx_name: Name of the index.
      **   idx_ispk: True if this index is the PK of a WITHOUT ROWID table.
      **   col_name: Name of indexed column, or NULL for index on expression.
      **   col_expr: Indexed expression, including COLLATE clause.
      **   col_alias: Alias used for column in 'intck_wrapper' table.
      */
      ", idx_cols(idx_name, idx_ispk, col_name, col_expr, col_alias) AS ("
      "  SELECT l.name, (l.origin=='pk' AND w.b), i.name, COALESCE(("
      "    SELECT parse_create_index(sql, i.seqno) FROM "
      "    sqlite_schema WHERE name = l.name"
      "  ), format('\"%w\"', i.name) || ' COLLATE ' || quote(i.coll)),"
      "  'c' || row_number() OVER ()"
      "  FROM "
      "      tabname t,"
      "      without_rowid w,"
      "      pragma_index_list(t.tab, t.db) l,"
      "      pragma_index_xinfo(l.name) i"
      "      WHERE i.key"
      "  UNION ALL"
      "  SELECT '', 1, '_rowid_', '_rowid_', 'r1' FROM without_rowid WHERE b=0"
      ")"
      ""
      ""
      /*
      ** For a PK declared as "PRIMARY KEY(a, b) ... WITHOUT ROWID", where
      ** the intck_wrapper aliases of "a" and "b" are "c1" and "c2":
      **
      **   o_pk:   "o.c1, o.c2"
      **   i_pk:   "i.'a', i.'b'"
      **   ...
      **   n_pk:   2
      */ 
      ", tabpk(db, tab, idx, o_pk, i_pk, q_pk, eq_pk, ps_pk, pk_pk, n_pk) AS ("
      "    WITH pkfields(f, a) AS ("
      "      SELECT i.col_name, i.col_alias FROM idx_cols i WHERE i.idx_ispk"
      "    )"
      "    SELECT t.db, t.tab, t.idx, "
      "           group_concat(a, ', '), "
      "           group_concat('i.'||quote(f), ', '), "
      "           group_concat('quote(o.'||a||')', ' || '','' || '),  "
      "           format('(%s)==(%s)',"
      "               group_concat('o.'||a, ', '), "
      "               group_concat(format('\"%w\"', f), ', ')"
      "           ),"
      "           group_concat('%s', ','),"
      "           group_concat('quote('||a||')', ', '),  "
      "           count(*)"
      "    FROM tabname t, pkfields"
      ")"
      ""
      ", idx(name, match_expr, partial, partial_alias, idx_ps, idx_idx) AS ("
      "  SELECT idx_name,"
      "    format('(%s,%s) IS (%s,%s)', "
      "           group_concat(i.col_expr, ', '), i_pk,"
      "           group_concat('o.'||i.col_alias, ', '), o_pk"
      "    ), "
      "    parse_create_index("
      "        (SELECT sql FROM sqlite_schema WHERE name=idx_name), -1"
      "    ),"
      "    'cond' || row_number() OVER ()"
      "    , group_concat('%s', ',')"
      "    , group_concat('quote('||i.col_alias||')', ', ')"
      "  FROM tabpk t, "
      "       without_rowid w,"
      "       idx_cols i"
      "  WHERE i.idx_ispk==0 "
      "  GROUP BY idx_name"
      ")"
      ""
      ", wrapper_with(s) AS ("
      "  SELECT 'intck_wrapper AS (\n  SELECT\n    ' || ("
      "      WITH f(a, b) AS ("
      "        SELECT col_expr, col_alias FROM idx_cols"
      "          UNION ALL "
      "        SELECT partial, partial_alias FROM idx WHERE partial IS NOT NULL"
      "      )"
      "      SELECT group_concat(format('%s AS %s', a, b), ',\n    ') FROM f"
      "    )"
      "    || format('\n  FROM %Q.%Q ', t.db, t.tab)"
           /* If the object being checked is a table, append "NOT INDEXED".
           ** Otherwise, append "INDEXED BY <index>", and then, if the index 
           ** is a partial index " WHERE <condition>".  */
      "    || CASE WHEN t.idx IS NULL THEN "
      "        'NOT INDEXED'"
      "       ELSE"
      "        format('INDEXED BY %Q%s', t.idx, ' WHERE '||i.partial)"
      "       END"
      "    || '\n)'"
      "    FROM tabname t LEFT JOIN idx i ON (i.name=t.idx)"
      ")"
      ""
  ;

  bAutoIndex = intckGetAutoIndex(p);
  if( bAutoIndex ) intckExec(p, "PRAGMA automatic_index = 0");

  bIsIndex = intckIsIndex(p, zObj);
  if( bIsIndex ){
    pStmt = intckPrepareFmt(p,
      /* Table idxname contains a single row. The first column, "db", contains
      ** the name of the db containing the table (e.g. "main") and the second,
      ** "tab", the name of the table itself.  */
      "WITH tabname(db, tab, idx) AS ("
      "  SELECT %Q, (SELECT tbl_name FROM %Q.sqlite_schema WHERE name=%Q), %Q "
      ")"
      ""
      ", whereclause(w_c) AS (%s)"
      ""
      "%s" /* zCommon */
      ""
      ", case_statement(c) AS ("
      "  SELECT "
      "    'CASE WHEN (' || group_concat(col_alias, ', ') || ', 1) IS (\n' "
      "    || '      SELECT ' || group_concat(col_expr, ', ') || ', 1 FROM '"
      "    || format('%%Q.%%Q NOT INDEXED WHERE %%s\n', t.db, t.tab, p.eq_pk)"
      "    || '    )\n  THEN NULL\n    '"
      "    || 'ELSE format(''surplus entry ('"
      "    ||   group_concat('%%s', ',') || ',' || p.ps_pk"
      "    || ') in index ' || t.idx || ''', ' "
      "    ||   group_concat('quote('||i.col_alias||')', ', ') || ', ' || p.pk_pk"
      "    || ')'"
      "    || '\n  END AS error_message'"
      "  FROM tabname t, tabpk p, idx_cols i WHERE i.idx_name=t.idx"
      ")"
      ""
      ", thiskey(k, n) AS ("
      "    SELECT group_concat(i.col_alias, ', ') || ', ' || p.o_pk, "
      "           count(*) + p.n_pk "
      "    FROM tabpk p, idx_cols i WHERE i.idx_name=p.idx"
      ")"
      ""
      ", main_select(m, n) AS ("
      "  SELECT format("
      "      'WITH %%s\n' ||"
      "      ', idx_checker AS (\n' ||"
      "      '  SELECT %%s,\n' ||"
      "      '  %%s\n' || "
      "      '  FROM intck_wrapper AS o\n' ||"
      "      ')\n',"
      "      ww.s, c, t.k"
      "  ), t.n"
      "  FROM case_statement, wrapper_with ww, thiskey t"
      ")"

      "SELECT m || "
      "    group_concat('SELECT * FROM idx_checker ' || w_c, ' UNION ALL '), n"
      " FROM "
      "main_select, whereclause "
      , p->zDb, p->zDb, zObj, zObj
      , zPrev ? zPrev : "VALUES('')", zCommon
      );
  }else{
    pStmt = intckPrepareFmt(p,
      /* Table tabname contains a single row. The first column, "db", contains
      ** the name of the db containing the table (e.g. "main") and the second,
      ** "tab", the name of the table itself.  */
      "WITH tabname(db, tab, idx, prev) AS (SELECT %Q, %Q, NULL, %Q)"
      ""
      "%s" /* zCommon */

      /* expr(e) contains one row for each index on table zObj. Value e
      ** is set to an expression that evaluates to NULL if the required
      ** entry is present in the index, or an error message otherwise.  */
      ", expr(e, p) AS ("
      "  SELECT format('CASE WHEN EXISTS \n"
      "    (SELECT 1 FROM %%Q.%%Q AS i INDEXED BY %%Q WHERE %%s%%s)\n"
      "    THEN NULL\n"
      "    ELSE format(''entry (%%s,%%s) missing from index %%s'', %%s, %%s)\n"
      "  END\n'"
      "    , t.db, t.tab, i.name, i.match_expr, ' AND (' || partial || ')',"
      "      i.idx_ps, t.ps_pk, i.name, i.idx_idx, t.pk_pk),"
      "    CASE WHEN partial IS NULL THEN NULL ELSE i.partial_alias END"
      "  FROM tabpk t, idx i"
      ")"

      ", numbered(ii, cond, e) AS ("
      "  SELECT 0, 'n.ii=0', 'NULL'"
      "    UNION ALL "
      "  SELECT row_number() OVER (),"
      "      '(n.ii='||row_number() OVER ()||COALESCE(' AND '||p||')', ')'), e"
      "  FROM expr"
      ")"

      ", counter_with(w) AS ("
      "    SELECT 'WITH intck_counter(ii) AS (\n  ' || "
      "       group_concat('SELECT '||ii, ' UNION ALL\n  ') "
      "    || '\n)' FROM numbered"
      ")"
      ""
      ", case_statement(c) AS ("
      "    SELECT 'CASE ' || "
      "    group_concat(format('\n  WHEN %%s THEN (%%s)', cond, e), '') ||"
      "    '\nEND AS error_message'"
      "    FROM numbered"
      ")"
      ""

      /* This table contains a single row consisting of a single value -
      ** the text of an SQL expression that may be used by the main SQL
      ** statement to output an SQL literal that can be used to resume
      ** the scan if it is suspended. e.g. for a rowid table, an expression
      ** like:
      **
      **     format('(%d,%d)', _rowid_, n.ii)
      */
      ", thiskey(k, n) AS ("
      "    SELECT o_pk || ', ii', n_pk+1 FROM tabpk"
      ")"
      ""
      ", whereclause(w_c) AS ("
      "    SELECT CASE WHEN prev!='' THEN "
      "    '\nWHERE (' || o_pk ||', n.ii) > ' || prev"
      "    ELSE ''"
      "    END"
      "    FROM tabpk, tabname"
      ")"
      ""
      ", main_select(m, n) AS ("
      "  SELECT format("
      "      '%%s, %%s\nSELECT %%s,\n%%s\nFROM intck_wrapper AS o"
               ", intck_counter AS n%%s\nORDER BY %%s', "
      "      w, ww.s, c, thiskey.k, whereclause.w_c, t.o_pk"
      "  ), thiskey.n"
      "  FROM case_statement, tabpk t, counter_with, "
      "       wrapper_with ww, thiskey, whereclause"
      ")"

      "SELECT m, n FROM main_select",
      p->zDb, zObj, zPrev, zCommon
    );
  }

  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
    zRet = intckMprintf(p, "%s", (const char*)sqlite3_column_text(pStmt, 0));
    if( pnKeyVal ){
      *pnKeyVal = sqlite3_column_int(pStmt, 1);
    }
  }
  intckFinalize(p, pStmt);

  if( bAutoIndex ) intckExec(p, "PRAGMA automatic_index = 1");
  return zRet;
}

/*
** Open a new integrity-check object.
*/
int sqlite3_intck_open(
  sqlite3 *db,                    /* Database handle to operate on */
  const char *zDbArg,             /* "main", "temp" etc. */
  sqlite3_intck **ppOut           /* OUT: New integrity-check handle */
){
  sqlite3_intck *pNew = 0;
  int rc = SQLITE_OK;
  const char *zDb = zDbArg ? zDbArg : "main";
  int nDb = (int)strlen(zDb);

  pNew = (sqlite3_intck*)sqlite3_malloc(sizeof(*pNew) + nDb + 1);
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    memset(pNew, 0, sizeof(*pNew));
    pNew->db = db;
    pNew->zDb = (const char*)&pNew[1];
    memcpy(&pNew[1], zDb, nDb+1);
    rc = sqlite3_create_function(db, "parse_create_index", 
        2, SQLITE_UTF8, 0, intckParseCreateIndexFunc, 0, 0
    );
    if( rc!=SQLITE_OK ){
      sqlite3_intck_close(pNew);
      pNew = 0;
    }
  }

  *ppOut = pNew;
  return rc;
}

/*
** Free the integrity-check object.
*/
void sqlite3_intck_close(sqlite3_intck *p){
  if( p ){
    sqlite3_finalize(p->pCheck);
    sqlite3_create_function(
        p->db, "parse_create_index", 1, SQLITE_UTF8, 0, 0, 0, 0
    );
    sqlite3_free(p->zObj);
    sqlite3_free(p->zKey);
    sqlite3_free(p->zTestSql);
    sqlite3_free(p->zErr);
    sqlite3_free(p->zMessage);
    sqlite3_free(p);
  }
}

/*
** Step the integrity-check object.
*/
int sqlite3_intck_step(sqlite3_intck *p){
  if( p->rc==SQLITE_OK ){

    if( p->zMessage ){
      sqlite3_free(p->zMessage);
      p->zMessage = 0;
    }

    if( p->bCorruptSchema ){
      p->rc = SQLITE_DONE;
    }else
    if( p->pCheck==0 ){
      intckFindObject(p);
      if( p->rc==SQLITE_OK ){
        if( p->zObj ){
          char *zSql = 0;
          zSql = intckCheckObjectSql(p, p->zObj, p->zKey, &p->nKeyVal);
          p->pCheck = intckPrepare(p, zSql);
          sqlite3_free(zSql);
          sqlite3_free(p->zKey);
          p->zKey = 0;
        }else{
          p->rc = SQLITE_DONE;
        }
      }else if( p->rc==SQLITE_CORRUPT ){
        p->rc = SQLITE_OK;
        p->zMessage = intckMprintf(p, "%s",
            "corruption found while reading database schema"
        );
        p->bCorruptSchema = 1;
      }
    }

    if( p->pCheck ){
      assert( p->rc==SQLITE_OK );
      if( sqlite3_step(p->pCheck)==SQLITE_ROW ){
        /* Normal case, do nothing. */
      }else{
        intckFinalize(p, p->pCheck);
        p->pCheck = 0;
        p->nKeyVal = 0;
        if( p->rc==SQLITE_CORRUPT ){
          p->rc = SQLITE_OK;
          p->zMessage = intckMprintf(p, 
              "corruption found while scanning database object %s", p->zObj
          );
        }
      }
    }
  }

  return p->rc;
}

/*
** Return a message describing the corruption encountered by the most recent
** call to sqlite3_intck_step(), or NULL if no corruption was encountered.
*/
const char *sqlite3_intck_message(sqlite3_intck *p){
  assert( p->pCheck==0 || p->zMessage==0 );
  if( p->zMessage ){
    return p->zMessage;
  }
  if( p->pCheck ){
    return (const char*)sqlite3_column_text(p->pCheck, 0);
  }
  return 0;
}

/*
** Return the error code and message.
*/
int sqlite3_intck_error(sqlite3_intck *p, const char **pzErr){
  if( pzErr ) *pzErr = p->zErr;
  return (p->rc==SQLITE_DONE ? SQLITE_OK : p->rc);
}

/*
** Close any read transaction the integrity-check object is holding open
** on the database.
*/
int sqlite3_intck_unlock(sqlite3_intck *p){
  if( p->rc==SQLITE_OK && p->pCheck ){
    assert( p->zKey==0 && p->nKeyVal>0 );
    intckSaveKey(p);
    intckFinalize(p, p->pCheck);
    p->pCheck = 0;
  }
  return p->rc;
}

/*
** Return the SQL statement used to check object zObj. Or, if zObj is 
** NULL, the current SQL statement.
*/
const char *sqlite3_intck_test_sql(sqlite3_intck *p, const char *zObj){
  sqlite3_free(p->zTestSql);
  if( zObj ){
    p->zTestSql = intckCheckObjectSql(p, zObj, 0, 0);
  }else{
    if( p->zObj ){
      p->zTestSql = intckCheckObjectSql(p, p->zObj, p->zKey, 0);
    }else{
      sqlite3_free(p->zTestSql);
      p->zTestSql = 0;
    }
  }
  return p->zTestSql;
}

/************************* End ext/intck/sqlite3intck.c ********************/
/************************* Begin ext/misc/stmtrand.c ******************/
/*
** 2024-05-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** An SQL function that return pseudo-random non-negative integers.
**
**      SELECT stmtrand(123);
**
** A special feature of this function is that the same sequence of random
** integers is returned for each invocation of the statement.  This makes
** the results repeatable, and hence useful for testing.  The argument is
** an integer which is the seed for the random number sequence.  The seed
** is used by the first invocation of this function only and is ignored
** for all subsequent calls within the same statement.
**
** Resetting a statement (sqlite3_reset()) also resets the random number
** sequence.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

/* State of the pseudo-random number generator */
typedef struct Stmtrand {
  unsigned int x, y;
} Stmtrand;

/* auxdata key */
#define STMTRAND_KEY  (-4418371)

/*
** Function:     stmtrand(SEED)
**
** Return a pseudo-random number.
*/
static void stmtrandFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Stmtrand *p;

  p = (Stmtrand*)sqlite3_get_auxdata(context, STMTRAND_KEY);
  if( p==0 ){
    unsigned int seed;
    p = sqlite3_malloc64( sizeof(*p) );
    if( p==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
    if( argc>=1 ){
      seed = (unsigned int)sqlite3_value_int(argv[0]);
    }else{
      seed = 0;
    }
    p->x = seed | 1;
    p->y = seed;
    sqlite3_set_auxdata(context, STMTRAND_KEY, p, sqlite3_free);
    p = (Stmtrand*)sqlite3_get_auxdata(context, STMTRAND_KEY);
    if( p==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  p->x = (p->x>>1) ^ ((1+~(p->x&1)) & 0xd0000001);
  p->y = p->y*1103515245 + 12345;
  sqlite3_result_int(context, (int)((p->x ^ p->y)&0x7fffffff));
}

#ifdef _WIN32

#endif
int sqlite3_stmtrand_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "stmtrand", 1, SQLITE_UTF8, 0,
                               stmtrandFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "stmtrand", 0, SQLITE_UTF8, 0,
                                 stmtrandFunc, 0, 0);
  }
  return rc;
}

/************************* End ext/misc/stmtrand.c ********************/
/************************* Begin ext/misc/vfstrace.c ******************/
/*
** 2011 March 16
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code implements a VFS shim that writes diagnostic
** output for each VFS call, similar to "strace".
**
** USAGE:
**
** This source file exports a single symbol which is the name of a
** function:
**
**   int vfstrace_register(
**     const char *zTraceName,         // Name of the newly constructed VFS
**     const char *zOldVfsName,        // Name of the underlying VFS
**     int (*xOut)(const char*,void*), // Output routine.  ex: fputs
**     void *pOutArg,                  // 2nd argument to xOut.  ex: stderr
**     int makeDefault                 // Make the new VFS the default
**   );
**
** Applications that want to trace their VFS usage must provide a callback
** function with this prototype:
**
**   int traceOutput(const char *zMessage, void *pAppData);
**
** This function will "output" the trace messages, where "output" can
** mean different things to different applications.  The traceOutput function
** for the command-line shell (see shell.c) is "fputs" from the standard
** library, which means that all trace output is written on the stream
** specified by the second argument.  In the case of the command-line shell
** the second argument is stderr.  Other applications might choose to output
** trace information to a file, over a socket, or write it into a buffer.
**
** The vfstrace_register() function creates a new "shim" VFS named by
** the zTraceName parameter.  A "shim" VFS is an SQLite backend that does
** not really perform the duties of a true backend, but simply filters or
** interprets VFS calls before passing them off to another VFS which does
** the actual work.  In this case the other VFS - the one that does the
** real work - is identified by the second parameter, zOldVfsName.  If
** the 2nd parameter is NULL then the default VFS is used.  The common
** case is for the 2nd parameter to be NULL.
**
** The third and fourth parameters are the pointer to the output function
** and the second argument to the output function.  For the SQLite
** command-line shell, when the -vfstrace option is used, these parameters
** are fputs and stderr, respectively.
**
** The fifth argument is true (non-zero) to cause the newly created VFS
** to become the default VFS.  The common case is for the fifth parameter
** to be true.
**
** The call to vfstrace_register() simply creates the shim VFS that does
** tracing.  The application must also arrange to use the new VFS for
** all database connections that are created and for which tracing is 
** desired.  This can be done by specifying the trace VFS using URI filename
** notation, or by specifying the trace VFS as the 4th parameter to
** sqlite3_open_v2() or by making the trace VFS be the default (by setting
** the 5th parameter of vfstrace_register() to 1).
**
**
** ENABLING VFSTRACE IN A COMMAND-LINE SHELL
**
** The SQLite command line shell implemented by the shell.c source file
** can be used with this module.  To compile in -vfstrace support, first
** gather this file (test_vfstrace.c), the shell source file (shell.c),
** and the SQLite amalgamation source files (sqlite3.c, sqlite3.h) into
** the working directory.  Then compile using a command like the following:
**
**    gcc -o sqlite3 -Os -I. -DSQLITE_ENABLE_VFSTRACE \
**        -DSQLITE_THREADSAFE=0 -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE \
**        -DHAVE_READLINE -DHAVE_USLEEP=1 \
**        shell.c test_vfstrace.c sqlite3.c -ldl -lreadline -lncurses
**
** The gcc command above works on Linux and provides (in addition to the
** -vfstrace option) support for FTS3 and FTS4, RTREE, and command-line
** editing using the readline library.  The command-line shell does not
** use threads so we added -DSQLITE_THREADSAFE=0 just to make the code
** run a little faster.   For compiling on a Mac, you'll probably need
** to omit the -DHAVE_READLINE, the -lreadline, and the -lncurses options.
** The compilation could be simplified to just this:
**
**    gcc -DSQLITE_ENABLE_VFSTRACE \
**         shell.c test_vfstrace.c sqlite3.c -ldl -lpthread
**
** In this second example, all unnecessary options have been removed
** Note that since the code is now threadsafe, we had to add the -lpthread
** option to pull in the pthreads library.
**
** To cross-compile for windows using MinGW, a command like this might
** work:
**
**    /opt/mingw/bin/i386-mingw32msvc-gcc -o sqlite3.exe -Os -I \
**         -DSQLITE_THREADSAFE=0 -DSQLITE_ENABLE_VFSTRACE \
**         shell.c test_vfstrace.c sqlite3.c
**
** Similar compiler commands will work on different systems.  The key
** invariants are (1) you must have -DSQLITE_ENABLE_VFSTRACE so that
** the shell.c source file will know to include the -vfstrace command-line
** option and (2) you must compile and link the three source files
** shell,c, test_vfstrace.c, and sqlite3.c.
**
** RUNTIME CONTROL OF VFSTRACE OUTPUT
**
** The application can use the "vfstrace" pragma to control which VFS
** APIs are traced.  To disable all output:
**
**    PRAGMA vfstrace('-all');
**
** To enable all output (which is the default setting):
**
**    PRAGMA vfstrace('+all');
**
** Individual APIs can be enabled or disabled by name, with or without
** the initial "x" character.  For example, to set up for tracing lock
** primitives only:
**
**    PRAGMA vfstrace('-all, +Lock,Unlock,ShmLock');
**
** The argument to the vfstrace pragma ignores capitalization and any
** characters other than alphabetics, '+', and '-'.
*/
#include <stdlib.h>
#include <string.h>
/* #include "sqlite3.h" */

/*
** An instance of this structure is attached to the each trace VFS to
** provide auxiliary information.
*/
typedef struct vfstrace_info vfstrace_info;
struct vfstrace_info {
  sqlite3_vfs *pRootVfs;              /* The underlying real VFS */
  int (*xOut)(const char*, void*);    /* Send output here */
  unsigned int mTrace;                /* Mask of interfaces to trace */
  u8 bOn;                             /* Tracing on/off */
  void *pOutArg;                      /* First argument to xOut */
  const char *zVfsName;               /* Name of this trace-VFS */
  sqlite3_vfs *pTraceVfs;             /* Pointer back to the trace VFS */
};

/*
** The sqlite3_file object for the trace VFS
*/
typedef struct vfstrace_file vfstrace_file;
struct vfstrace_file {
  sqlite3_file base;        /* Base class.  Must be first */
  vfstrace_info *pInfo;     /* The trace-VFS to which this file belongs */
  const char *zFName;       /* Base name of the file */
  sqlite3_file *pReal;      /* The real underlying file */
};

/*
** Bit values for vfstrace_info.mTrace.
*/
#define VTR_CLOSE           0x00000001
#define VTR_READ            0x00000002
#define VTR_WRITE           0x00000004
#define VTR_TRUNC           0x00000008
#define VTR_SYNC            0x00000010
#define VTR_FSIZE           0x00000020
#define VTR_LOCK            0x00000040
#define VTR_UNLOCK          0x00000080
#define VTR_CRL             0x00000100
#define VTR_FCTRL           0x00000200
#define VTR_SECSZ           0x00000400
#define VTR_DEVCHAR         0x00000800
#define VTR_SHMLOCK         0x00001000
#define VTR_SHMMAP          0x00002000
#define VTR_SHMBAR          0x00004000
#define VTR_SHMUNMAP        0x00008000
#define VTR_OPEN            0x00010000
#define VTR_DELETE          0x00020000
#define VTR_ACCESS          0x00040000
#define VTR_FULLPATH        0x00080000
#define VTR_DLOPEN          0x00100000
#define VTR_DLERR           0x00200000
#define VTR_DLSYM           0x00400000
#define VTR_DLCLOSE         0x00800000
#define VTR_RAND            0x01000000
#define VTR_SLEEP           0x02000000
#define VTR_CURTIME         0x04000000
#define VTR_LASTERR         0x08000000
#define VTR_FETCH           0x10000000   /* Also coverse xUnfetch */

/*
** Method declarations for vfstrace_file.
*/
static int vfstraceClose(sqlite3_file*);
static int vfstraceRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int vfstraceWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64);
static int vfstraceTruncate(sqlite3_file*, sqlite3_int64 size);
static int vfstraceSync(sqlite3_file*, int flags);
static int vfstraceFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int vfstraceLock(sqlite3_file*, int);
static int vfstraceUnlock(sqlite3_file*, int);
static int vfstraceCheckReservedLock(sqlite3_file*, int *);
static int vfstraceFileControl(sqlite3_file*, int op, void *pArg);
static int vfstraceSectorSize(sqlite3_file*);
static int vfstraceDeviceCharacteristics(sqlite3_file*);
static int vfstraceShmLock(sqlite3_file*,int,int,int);
static int vfstraceShmMap(sqlite3_file*,int,int,int, void volatile **);
static void vfstraceShmBarrier(sqlite3_file*);
static int vfstraceShmUnmap(sqlite3_file*,int);

/*
** Method declarations for vfstrace_vfs.
*/
static int vfstraceOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
static int vfstraceDelete(sqlite3_vfs*, const char *zName, int syncDir);
static int vfstraceAccess(sqlite3_vfs*, const char *zName, int flags, int *);
static int vfstraceFullPathname(sqlite3_vfs*, const char *zName, int, char *);
static void *vfstraceDlOpen(sqlite3_vfs*, const char *zFilename);
static void vfstraceDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
static void (*vfstraceDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void);
static void vfstraceDlClose(sqlite3_vfs*, void*);
static int vfstraceRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int vfstraceSleep(sqlite3_vfs*, int microseconds);
static int vfstraceCurrentTime(sqlite3_vfs*, double*);
static int vfstraceGetLastError(sqlite3_vfs*, int, char*);
static int vfstraceCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
static int vfstraceSetSystemCall(sqlite3_vfs*,const char*, sqlite3_syscall_ptr);
static sqlite3_syscall_ptr vfstraceGetSystemCall(sqlite3_vfs*, const char *);
static const char *vfstraceNextSystemCall(sqlite3_vfs*, const char *zName);

/*
** Return a pointer to the tail of the pathname.  Examples:
**
**     /home/drh/xyzzy.txt -> xyzzy.txt
**     xyzzy.txt           -> xyzzy.txt
*/
static const char *fileTail(const char *z){
  size_t i;
  if( z==0 ) return 0;
  i = strlen(z)-1;
  while( i>0 && z[i-1]!='/' ){ i--; }
  return &z[i];
}

/*
** Send trace output defined by zFormat and subsequent arguments.
*/
static void vfstrace_printf(
  vfstrace_info *pInfo,
  const char *zFormat,
  ...
){
  va_list ap;
  char *zMsg;
  if( pInfo->bOn ){
    va_start(ap, zFormat);
    zMsg = sqlite3_vmprintf(zFormat, ap);
    va_end(ap);
    pInfo->xOut(zMsg, pInfo->pOutArg);
    sqlite3_free(zMsg);
  }
}

/*
** Try to convert an error code into a symbolic name for that error code.
*/
static const char *vfstrace_errcode_name(int rc ){
  const char *zVal = 0;
  switch( rc ){
    case SQLITE_OK:                 zVal = "SQLITE_OK";                 break;
    case SQLITE_INTERNAL:           zVal = "SQLITE_INTERNAL";           break;
    case SQLITE_ERROR:              zVal = "SQLITE_ERROR";              break;
    case SQLITE_PERM:               zVal = "SQLITE_PERM";               break;
    case SQLITE_ABORT:              zVal = "SQLITE_ABORT";              break;
    case SQLITE_BUSY:               zVal = "SQLITE_BUSY";               break;
    case SQLITE_LOCKED:             zVal = "SQLITE_LOCKED";             break;
    case SQLITE_NOMEM:              zVal = "SQLITE_NOMEM";              break;
    case SQLITE_READONLY:           zVal = "SQLITE_READONLY";           break;
    case SQLITE_INTERRUPT:          zVal = "SQLITE_INTERRUPT";          break;
    case SQLITE_IOERR:              zVal = "SQLITE_IOERR";              break;
    case SQLITE_CORRUPT:            zVal = "SQLITE_CORRUPT";            break;
    case SQLITE_NOTFOUND:           zVal = "SQLITE_NOTFOUND";           break;
    case SQLITE_FULL:               zVal = "SQLITE_FULL";               break;
    case SQLITE_CANTOPEN:           zVal = "SQLITE_CANTOPEN";           break;
    case SQLITE_PROTOCOL:           zVal = "SQLITE_PROTOCOL";           break;
    case SQLITE_EMPTY:              zVal = "SQLITE_EMPTY";              break;
    case SQLITE_SCHEMA:             zVal = "SQLITE_SCHEMA";             break;
    case SQLITE_TOOBIG:             zVal = "SQLITE_TOOBIG";             break;
    case SQLITE_CONSTRAINT:         zVal = "SQLITE_CONSTRAINT";         break;
    case SQLITE_MISMATCH:           zVal = "SQLITE_MISMATCH";           break;
    case SQLITE_MISUSE:             zVal = "SQLITE_MISUSE";             break;
    case SQLITE_NOLFS:              zVal = "SQLITE_NOLFS";              break;
    case SQLITE_IOERR_READ:         zVal = "SQLITE_IOERR_READ";         break;
    case SQLITE_IOERR_SHORT_READ:   zVal = "SQLITE_IOERR_SHORT_READ";   break;
    case SQLITE_IOERR_WRITE:        zVal = "SQLITE_IOERR_WRITE";        break;
    case SQLITE_IOERR_FSYNC:        zVal = "SQLITE_IOERR_FSYNC";        break;
    case SQLITE_IOERR_DIR_FSYNC:    zVal = "SQLITE_IOERR_DIR_FSYNC";    break;
    case SQLITE_IOERR_TRUNCATE:     zVal = "SQLITE_IOERR_TRUNCATE";     break;
    case SQLITE_IOERR_FSTAT:        zVal = "SQLITE_IOERR_FSTAT";        break;
    case SQLITE_IOERR_UNLOCK:       zVal = "SQLITE_IOERR_UNLOCK";       break;
    case SQLITE_IOERR_RDLOCK:       zVal = "SQLITE_IOERR_RDLOCK";       break;
    case SQLITE_IOERR_DELETE:       zVal = "SQLITE_IOERR_DELETE";       break;
    case SQLITE_IOERR_BLOCKED:      zVal = "SQLITE_IOERR_BLOCKED";      break;
    case SQLITE_IOERR_NOMEM:        zVal = "SQLITE_IOERR_NOMEM";        break;
    case SQLITE_IOERR_ACCESS:       zVal = "SQLITE_IOERR_ACCESS";       break;
    case SQLITE_IOERR_CHECKRESERVEDLOCK:
                               zVal = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
    case SQLITE_IOERR_LOCK:         zVal = "SQLITE_IOERR_LOCK";         break;
    case SQLITE_IOERR_CLOSE:        zVal = "SQLITE_IOERR_CLOSE";        break;
    case SQLITE_IOERR_DIR_CLOSE:    zVal = "SQLITE_IOERR_DIR_CLOSE";    break;
    case SQLITE_IOERR_SHMOPEN:      zVal = "SQLITE_IOERR_SHMOPEN";      break;
    case SQLITE_IOERR_SHMSIZE:      zVal = "SQLITE_IOERR_SHMSIZE";      break;
    case SQLITE_IOERR_SHMLOCK:      zVal = "SQLITE_IOERR_SHMLOCK";      break;
    case SQLITE_IOERR_SHMMAP:       zVal = "SQLITE_IOERR_SHMMAP";       break;
    case SQLITE_IOERR_SEEK:         zVal = "SQLITE_IOERR_SEEK";         break;
    case SQLITE_IOERR_GETTEMPPATH:  zVal = "SQLITE_IOERR_GETTEMPPATH";  break;
    case SQLITE_IOERR_CONVPATH:     zVal = "SQLITE_IOERR_CONVPATH";     break;
    case SQLITE_READONLY_DBMOVED:   zVal = "SQLITE_READONLY_DBMOVED";   break;
    case SQLITE_LOCKED_SHAREDCACHE: zVal = "SQLITE_LOCKED_SHAREDCACHE"; break;
    case SQLITE_BUSY_RECOVERY:      zVal = "SQLITE_BUSY_RECOVERY";      break;
    case SQLITE_CANTOPEN_NOTEMPDIR: zVal = "SQLITE_CANTOPEN_NOTEMPDIR"; break;
  }
  return zVal;
}

/*
** Convert value rc into a string and print it using zFormat.  zFormat
** should have exactly one %s
*/
static void vfstrace_print_errcode(
  vfstrace_info *pInfo,
  const char *zFormat,
  int rc
){
  const char *zVal;
  char zBuf[50];
  zVal = vfstrace_errcode_name(rc);
  if( zVal==0 ){
    zVal = vfstrace_errcode_name(rc&0xff);
    if( zVal ){
      sqlite3_snprintf(sizeof(zBuf), zBuf, "%s | 0x%x", zVal, rc&0xffff00);
    }else{
      sqlite3_snprintf(sizeof(zBuf), zBuf, "%d (0x%x)", rc, rc);
    }
    zVal = zBuf;
  }
  vfstrace_printf(pInfo, zFormat, zVal);
}

/*
** Append to a buffer.
*/
static void strappend(char *z, int *pI, const char *zAppend){
  int i = *pI;
  while( zAppend[0] ){ z[i++] = *(zAppend++); }
  z[i] = 0;
  *pI = i;
}

/*
** Turn tracing output on or off according to mMask.
*/
static void vfstraceOnOff(vfstrace_info *pInfo, unsigned int mMask){
  pInfo->bOn = (pInfo->mTrace & mMask)!=0;
}

/*
** Close an vfstrace-file.
*/
static int vfstraceClose(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_CLOSE);
  vfstrace_printf(pInfo, "%s.xClose(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xClose(p->pReal);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( rc==SQLITE_OK ){
    sqlite3_free((void*)p->base.pMethods);
    p->base.pMethods = 0;
  }
  return rc;
}

/*
** Read data from an vfstrace-file.
*/
static int vfstraceRead(
  sqlite3_file *pFile, 
  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_READ);
  vfstrace_printf(pInfo, "%s.xRead(%s,n=%d,ofst=%lld)",
                  pInfo->zVfsName, p->zFName, iAmt, iOfst);
  rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Write data to an vfstrace-file.
*/
static int vfstraceWrite(
  sqlite3_file *pFile, 
  const void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_WRITE);
  vfstrace_printf(pInfo, "%s.xWrite(%s,n=%d,ofst=%lld)",
                  pInfo->zVfsName, p->zFName, iAmt, iOfst);
  rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Truncate an vfstrace-file.
*/
static int vfstraceTruncate(sqlite3_file *pFile, sqlite_int64 size){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_TRUNC);
  vfstrace_printf(pInfo, "%s.xTruncate(%s,%lld)", pInfo->zVfsName, p->zFName,
                  size);
  rc = p->pReal->pMethods->xTruncate(p->pReal, size);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Sync an vfstrace-file.
*/
static int vfstraceSync(sqlite3_file *pFile, int flags){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  int i;
  char zBuf[100];
  memcpy(zBuf, "|0", 3);
  i = 0;
  if( flags & SQLITE_SYNC_FULL )        strappend(zBuf, &i, "|FULL");
  else if( flags & SQLITE_SYNC_NORMAL ) strappend(zBuf, &i, "|NORMAL");
  if( flags & SQLITE_SYNC_DATAONLY )    strappend(zBuf, &i, "|DATAONLY");
  if( flags & ~(SQLITE_SYNC_FULL|SQLITE_SYNC_DATAONLY) ){
    sqlite3_snprintf(sizeof(zBuf)-i, &zBuf[i], "|0x%x", flags);
  }
  vfstraceOnOff(pInfo, VTR_SYNC);
  vfstrace_printf(pInfo, "%s.xSync(%s,%s)", pInfo->zVfsName, p->zFName,
                  &zBuf[1]);
  rc = p->pReal->pMethods->xSync(p->pReal, flags);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Return the current file-size of an vfstrace-file.
*/
static int vfstraceFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_FSIZE);
  vfstrace_printf(pInfo, "%s.xFileSize(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);
  vfstrace_print_errcode(pInfo, " -> %s,", rc);
  vfstrace_printf(pInfo, " size=%lld\n", *pSize);
  return rc;
}

/*
** Return the name of a lock.
*/
static const char *lockName(int eLock){
  const char *azLockNames[] = {
     "NONE", "SHARED", "RESERVED", "PENDING", "EXCLUSIVE"
  };
  if( eLock<0 || eLock>=(int)(sizeof(azLockNames)/sizeof(azLockNames[0])) ){
    return "???";
  }else{
    return azLockNames[eLock];
  }
}

/*
** Lock an vfstrace-file.
*/
static int vfstraceLock(sqlite3_file *pFile, int eLock){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_LOCK);
  vfstrace_printf(pInfo, "%s.xLock(%s,%s)", pInfo->zVfsName, p->zFName,
                  lockName(eLock));
  rc = p->pReal->pMethods->xLock(p->pReal, eLock);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Unlock an vfstrace-file.
*/
static int vfstraceUnlock(sqlite3_file *pFile, int eLock){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_UNLOCK);
  vfstrace_printf(pInfo, "%s.xUnlock(%s,%s)", pInfo->zVfsName, p->zFName,
                  lockName(eLock));
  rc = p->pReal->pMethods->xUnlock(p->pReal, eLock);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Check if another file-handle holds a RESERVED lock on an vfstrace-file.
*/
static int vfstraceCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_CRL);
  vfstrace_printf(pInfo, "%s.xCheckReservedLock(%s,%d)", 
                  pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=%d\n", *pResOut);
  return rc;
}

/*
** File control method. For custom operations on an vfstrace-file.
*/
static int vfstraceFileControl(sqlite3_file *pFile, int op, void *pArg){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  char zBuf[100];
  char zBuf2[100];
  char *zOp;
  char *zRVal = 0;
  vfstraceOnOff(pInfo, VTR_FCTRL);
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE:           zOp = "LOCKSTATE";           break;
    case SQLITE_GET_LOCKPROXYFILE:         zOp = "GET_LOCKPROXYFILE";   break;
    case SQLITE_SET_LOCKPROXYFILE:         zOp = "SET_LOCKPROXYFILE";   break;
    case SQLITE_LAST_ERRNO:                zOp = "LAST_ERRNO";          break;
    case SQLITE_FCNTL_SIZE_HINT: {
      sqlite3_snprintf(sizeof(zBuf), zBuf, "SIZE_HINT,%lld",
                       *(sqlite3_int64*)pArg);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      sqlite3_snprintf(sizeof(zBuf), zBuf, "CHUNK_SIZE,%d", *(int*)pArg);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_FILE_POINTER:        zOp = "FILE_POINTER";        break;
    case SQLITE_FCNTL_WIN32_AV_RETRY:      zOp = "WIN32_AV_RETRY";      break;
    case SQLITE_FCNTL_PERSIST_WAL: {
       sqlite3_snprintf(sizeof(zBuf), zBuf, "PERSIST_WAL,%d", *(int*)pArg);
       zOp = zBuf;
       break;
    }
    case SQLITE_FCNTL_OVERWRITE:           zOp = "OVERWRITE";           break;
    case SQLITE_FCNTL_VFSNAME:             zOp = "VFSNAME";             break;
    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: zOp = "POWERSAFE_OVERWRITE"; break;
    case SQLITE_FCNTL_PRAGMA: {
      const char *const* a = (const char*const*)pArg;
      if( a[1] && strcmp(a[1],"vfstrace")==0 && a[2] ){
        const u8 *zArg = (const u8*)a[2];
        if( zArg[0]>='0' && zArg[0]<='9' ){
          pInfo->mTrace = (sqlite3_uint64)strtoll(a[2], 0, 0);
        }else{
          static const struct {
            const char *z;
            unsigned int m;
          } aKw[] = {
            { "all",                   0xffffffff   },
            { "close",                 VTR_CLOSE    },
            { "read",                  VTR_READ     },
            { "write",                 VTR_WRITE    },
            { "truncate",              VTR_TRUNC    },
            { "sync",                  VTR_SYNC     },
            { "filesize",              VTR_FSIZE    },
            { "lock",                  VTR_LOCK     },
            { "unlock",                VTR_UNLOCK   },
            { "checkreservedlock",     VTR_CRL      },
            { "filecontrol",           VTR_FCTRL    },
            { "sectorsize",            VTR_SECSZ    },
            { "devicecharacteristics", VTR_DEVCHAR  },
            { "shmlock",               VTR_SHMLOCK  },
            { "shmmap",                VTR_SHMMAP   },
            { "shmummap",              VTR_SHMUNMAP },
            { "shmbarrier",            VTR_SHMBAR   },
            { "open",                  VTR_OPEN     },
            { "delete",                VTR_DELETE   },
            { "access",                VTR_ACCESS   },
            { "fullpathname",          VTR_FULLPATH },
            { "dlopen",                VTR_DLOPEN   },
            { "dlerror",               VTR_DLERR    },
            { "dlsym",                 VTR_DLSYM    },
            { "dlclose",               VTR_DLCLOSE  },
            { "randomness",            VTR_RAND     },
            { "sleep",                 VTR_SLEEP    },
            { "currenttime",           VTR_CURTIME  },
            { "currenttimeint64",      VTR_CURTIME  },
            { "getlasterror",          VTR_LASTERR  },
            { "fetch",                 VTR_FETCH    },
          };
          int onOff = 1;
          while( zArg[0] ){
            int jj, n;
            while( zArg[0]!=0 && zArg[0]!='-' && zArg[0]!='+'
                   && !isalpha(zArg[0]) ) zArg++;
            if( zArg[0]==0 ) break;
            if( zArg[0]=='-' ){
              onOff = 0;
              zArg++;
            }else if( zArg[0]=='+' ){
              onOff = 1;
              zArg++;
            }
            while( !isalpha(zArg[0]) ){
              if( zArg[0]==0 ) break;
              zArg++;
            }
            if( zArg[0]=='x' && isalpha(zArg[1]) ) zArg++;
            for(n=0; isalpha(zArg[n]); n++){}
            for(jj=0; jj<(int)(sizeof(aKw)/sizeof(aKw[0])); jj++){
              if( sqlite3_strnicmp(aKw[jj].z,(const char*)zArg,n)==0 ){
                if( onOff ){
                  pInfo->mTrace |= aKw[jj].m;
                }else{
                  pInfo->mTrace &= ~aKw[jj].m;
                }
                break;
              }
            }
            zArg += n;
          }
        }
      }
      sqlite3_snprintf(sizeof(zBuf), zBuf, "PRAGMA,[%s,%s]",a[1],a[2]);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_BUSYHANDLER:         zOp = "BUSYHANDLER";         break;
    case SQLITE_FCNTL_TEMPFILENAME:        zOp = "TEMPFILENAME";        break;
    case SQLITE_FCNTL_MMAP_SIZE: {
      sqlite3_int64 iMMap = *(sqlite3_int64*)pArg;
      sqlite3_snprintf(sizeof(zBuf), zBuf, "MMAP_SIZE,%lld",iMMap);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_TRACE:               zOp = "TRACE";               break;
    case SQLITE_FCNTL_HAS_MOVED:           zOp = "HAS_MOVED";           break;
    case SQLITE_FCNTL_SYNC:                zOp = "SYNC";                break;
    case SQLITE_FCNTL_COMMIT_PHASETWO:     zOp = "COMMIT_PHASETWO";     break;
    case SQLITE_FCNTL_WIN32_SET_HANDLE:    zOp = "WIN32_SET_HANDLE";    break;
    case SQLITE_FCNTL_WAL_BLOCK:           zOp = "WAL_BLOCK";           break;
    case SQLITE_FCNTL_ZIPVFS:              zOp = "ZIPVFS";              break; 
    case SQLITE_FCNTL_RBU:                 zOp = "RBU";                 break;
    case SQLITE_FCNTL_VFS_POINTER:         zOp = "VFS_POINTER";         break;
    case SQLITE_FCNTL_JOURNAL_POINTER:     zOp = "JOURNAL_POINTER";     break;
    case SQLITE_FCNTL_WIN32_GET_HANDLE:    zOp = "WIN32_GET_HANDLE";    break;
    case SQLITE_FCNTL_PDB:                 zOp = "PDB";                 break;
    case SQLITE_FCNTL_BEGIN_ATOMIC_WRITE:  zOp = "BEGIN_ATOMIC_WRITE";  break;
    case SQLITE_FCNTL_COMMIT_ATOMIC_WRITE: zOp = "COMMIT_ATOMIC_WRITE"; break;
    case SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE: {
       zOp = "ROLLBACK_ATOMIC_WRITE";
       break;
    }
    case SQLITE_FCNTL_LOCK_TIMEOUT: {
       sqlite3_snprintf(sizeof(zBuf), zBuf, "LOCK_TIMEOUT,%d", *(int*)pArg);
       zOp = zBuf;
       break;
    }
    case SQLITE_FCNTL_DATA_VERSION:        zOp = "DATA_VERSION";        break;
    case SQLITE_FCNTL_SIZE_LIMIT:          zOp = "SIZE_LIMIT";          break;
    case SQLITE_FCNTL_CKPT_DONE:           zOp = "CKPT_DONE";           break;
    case SQLITE_FCNTL_RESERVE_BYTES:       zOp = "RESERVED_BYTES";      break;
    case SQLITE_FCNTL_CKPT_START:          zOp = "CKPT_START";          break;
    case SQLITE_FCNTL_EXTERNAL_READER:     zOp = "EXTERNAL_READER";     break;
    case SQLITE_FCNTL_CKSM_FILE:           zOp = "CKSM_FILE";           break;
    case SQLITE_FCNTL_RESET_CACHE:         zOp = "RESET_CACHE";         break;
    case 0xca093fa0:                       zOp = "DB_UNCHANGED";        break;
    default: {
      sqlite3_snprintf(sizeof zBuf, zBuf, "%d", op);
      zOp = zBuf;
      break;
    }
  }
  vfstrace_printf(pInfo, "%s.xFileControl(%s,%s)",
                  pInfo->zVfsName, p->zFName, zOp);
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  if( rc==SQLITE_OK ){
    switch( op ){
      case SQLITE_FCNTL_VFSNAME: {
        *(char**)pArg = sqlite3_mprintf("vfstrace.%s/%z",
                                    pInfo->zVfsName, *(char**)pArg);
        zRVal = *(char**)pArg;
        break;
      }
      case SQLITE_FCNTL_MMAP_SIZE: {
        sqlite3_snprintf(sizeof(zBuf2), zBuf2, "%lld", *(sqlite3_int64*)pArg);
        zRVal = zBuf2;
        break;
      }
      case SQLITE_FCNTL_HAS_MOVED:
      case SQLITE_FCNTL_PERSIST_WAL: {
        sqlite3_snprintf(sizeof(zBuf2), zBuf2, "%d", *(int*)pArg);
        zRVal = zBuf2;
        break;
      }
      case SQLITE_FCNTL_PRAGMA:
      case SQLITE_FCNTL_TEMPFILENAME: {
        zRVal = *(char**)pArg;
        break;
      }
    }
  }
  if( zRVal ){
    vfstrace_print_errcode(pInfo, " -> %s", rc);
    vfstrace_printf(pInfo, ", %s\n", zRVal);
  }else{
    vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  }
  return rc;
}

/*
** Return the sector-size in bytes for an vfstrace-file.
*/
static int vfstraceSectorSize(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_SECSZ);
  vfstrace_printf(pInfo, "%s.xSectorSize(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xSectorSize(p->pReal);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Return the device characteristic flags supported by an vfstrace-file.
*/
static int vfstraceDeviceCharacteristics(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_DEVCHAR);
  vfstrace_printf(pInfo, "%s.xDeviceCharacteristics(%s)",
                  pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal);
  vfstrace_printf(pInfo, " -> 0x%08x\n", rc);
  return rc;
}

/*
** Shared-memory operations.
*/
static int vfstraceShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
  static const char *azLockName[] = {
     "WRITE",
     "CKPT",
     "RECOVER",
     "READ0",
     "READ1",
     "READ2",
     "READ3",
     "READ4",
  };
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  char zLck[100];
  int i = 0;
  vfstraceOnOff(pInfo, VTR_SHMLOCK);
  memcpy(zLck, "|0", 3);
  if( flags & SQLITE_SHM_UNLOCK )    strappend(zLck, &i, "|UNLOCK");
  if( flags & SQLITE_SHM_LOCK )      strappend(zLck, &i, "|LOCK");
  if( flags & SQLITE_SHM_SHARED )    strappend(zLck, &i, "|SHARED");
  if( flags & SQLITE_SHM_EXCLUSIVE ) strappend(zLck, &i, "|EXCLUSIVE");
  if( flags & ~(0xf) ){
     sqlite3_snprintf(sizeof(zLck)-i, &zLck[i], "|0x%x", flags);
  }
  if( ofst>=0 && ofst<(int)(sizeof(azLockName)/sizeof(azLockName[0])) ){
    vfstrace_printf(pInfo, "%s.xShmLock(%s,ofst=%d(%s),n=%d,%s)",
                  pInfo->zVfsName, p->zFName, ofst, azLockName[ofst],
                  n, &zLck[1]);
  }else{
    vfstrace_printf(pInfo, "%s.xShmLock(%s,ofst=5d,n=%d,%s)",
                  pInfo->zVfsName, p->zFName, ofst,
                  n, &zLck[1]);
  }
  rc = p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static int vfstraceShmMap(
  sqlite3_file *pFile, 
  int iRegion, 
  int szRegion, 
  int isWrite, 
  void volatile **pp
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_SHMMAP);
  vfstrace_printf(pInfo, "%s.xShmMap(%s,iRegion=%d,szRegion=%d,isWrite=%d,*)",
                  pInfo->zVfsName, p->zFName, iRegion, szRegion, isWrite);
  rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static void vfstraceShmBarrier(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  vfstraceOnOff(pInfo, VTR_SHMBAR);
  vfstrace_printf(pInfo, "%s.xShmBarrier(%s)\n", pInfo->zVfsName, p->zFName);
  p->pReal->pMethods->xShmBarrier(p->pReal);
}
static int vfstraceShmUnmap(sqlite3_file *pFile, int delFlag){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_SHMUNMAP);
  vfstrace_printf(pInfo, "%s.xShmUnmap(%s,delFlag=%d)",
                  pInfo->zVfsName, p->zFName, delFlag);
  rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static int vfstraceFetch(sqlite3_file *pFile, i64 iOff, int nAmt, void **pptr){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_FETCH);
  vfstrace_printf(pInfo, "%s.xFetch(%s,iOff=%lld,nAmt=%d,p=%p)",
                  pInfo->zVfsName, p->zFName, iOff, nAmt, *pptr);
  rc = p->pReal->pMethods->xFetch(p->pReal, iOff, nAmt, pptr);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static int vfstraceUnfetch(sqlite3_file *pFile, i64 iOff, void *ptr){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_FETCH);
  vfstrace_printf(pInfo, "%s.xUnfetch(%s,iOff=%lld,p=%p)",
                  pInfo->zVfsName, p->zFName, iOff, ptr);
  rc = p->pReal->pMethods->xUnfetch(p->pReal, iOff, ptr);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}


/*
** Open an vfstrace file handle.
*/
static int vfstraceOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  int rc;
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  p->pInfo = pInfo;
  p->zFName = zName ? fileTail(zName) : "<temp>";
  p->pReal = (sqlite3_file *)&p[1];
  rc = pRoot->xOpen(pRoot, zName, p->pReal, flags, pOutFlags);
  vfstraceOnOff(pInfo, VTR_OPEN);
  vfstrace_printf(pInfo, "%s.xOpen(%s,flags=0x%x)",
                  pInfo->zVfsName, p->zFName, flags);
  if( p->pReal->pMethods ){
    sqlite3_io_methods *pNew = sqlite3_malloc64( sizeof(*pNew) );
    const sqlite3_io_methods *pSub = p->pReal->pMethods;
    memset(pNew, 0, sizeof(*pNew));
    pNew->iVersion = pSub->iVersion;
    pNew->xClose = vfstraceClose;
    pNew->xRead = vfstraceRead;
    pNew->xWrite = vfstraceWrite;
    pNew->xTruncate = vfstraceTruncate;
    pNew->xSync = vfstraceSync;
    pNew->xFileSize = vfstraceFileSize;
    pNew->xLock = vfstraceLock;
    pNew->xUnlock = vfstraceUnlock;
    pNew->xCheckReservedLock = vfstraceCheckReservedLock;
    pNew->xFileControl = vfstraceFileControl;
    pNew->xSectorSize = vfstraceSectorSize;
    pNew->xDeviceCharacteristics = vfstraceDeviceCharacteristics;
    if( pNew->iVersion>=2 ){
      pNew->xShmMap = pSub->xShmMap ? vfstraceShmMap : 0;
      pNew->xShmLock = pSub->xShmLock ? vfstraceShmLock : 0;
      pNew->xShmBarrier = pSub->xShmBarrier ? vfstraceShmBarrier : 0;
      pNew->xShmUnmap = pSub->xShmUnmap ? vfstraceShmUnmap : 0;
    }
    if( pNew->iVersion>=3 ){
      pNew->xFetch = pSub->xFetch ? vfstraceFetch : 0;
      pNew->xUnfetch = pSub->xUnfetch ? vfstraceUnfetch : 0;
    }
    pFile->pMethods = pNew;
  }
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  if( pOutFlags ){
    vfstrace_printf(pInfo, ", outFlags=0x%x\n", *pOutFlags);
  }else{
    vfstrace_printf(pInfo, "\n");
  }
  return rc;
}

/*
** Delete the file located at zPath. If the dirSync argument is true,
** ensure the file-system modifications are synced to disk before
** returning.
*/
static int vfstraceDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_DELETE);
  vfstrace_printf(pInfo, "%s.xDelete(\"%s\",%d)",
                  pInfo->zVfsName, zPath, dirSync);
  rc = pRoot->xDelete(pRoot, zPath, dirSync);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Test for access permissions. Return true if the requested permission
** is available, or false otherwise.
*/
static int vfstraceAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_ACCESS);
  vfstrace_printf(pInfo, "%s.xAccess(\"%s\",%d)",
                  pInfo->zVfsName, zPath, flags);
  rc = pRoot->xAccess(pRoot, zPath, flags, pResOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=%d\n", *pResOut);
  return rc;
}

/*
** Populate buffer zOut with the full canonical pathname corresponding
** to the pathname in zPath. zOut is guaranteed to point to a buffer
** of at least (DEVSYM_MAX_PATHNAME+1) bytes.
*/
static int vfstraceFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nOut, 
  char *zOut
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_FULLPATH);
  vfstrace_printf(pInfo, "%s.xFullPathname(\"%s\")",
                  pInfo->zVfsName, zPath);
  rc = pRoot->xFullPathname(pRoot, zPath, nOut, zOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=\"%.*s\"\n", nOut, zOut);
  return rc;
}

/*
** Open the dynamic library located at zPath and return a handle.
*/
static void *vfstraceDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_DLOPEN);
  vfstrace_printf(pInfo, "%s.xDlOpen(\"%s\")\n", pInfo->zVfsName, zPath);
  return pRoot->xDlOpen(pRoot, zPath);
}

/*
** Populate the buffer zErrMsg (size nByte bytes) with a human readable
** utf-8 string describing the most recent error encountered associated 
** with dynamic libraries.
*/
static void vfstraceDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_DLERR);
  vfstrace_printf(pInfo, "%s.xDlError(%d)", pInfo->zVfsName, nByte);
  pRoot->xDlError(pRoot, nByte, zErrMsg);
  vfstrace_printf(pInfo, " -> \"%s\"", zErrMsg);
}

/*
** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
*/
static void (*vfstraceDlSym(sqlite3_vfs *pVfs,void *p,const char *zSym))(void){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstrace_printf(pInfo, "%s.xDlSym(\"%s\")\n", pInfo->zVfsName, zSym);
  return pRoot->xDlSym(pRoot, p, zSym);
}

/*
** Close the dynamic library handle pHandle.
*/
static void vfstraceDlClose(sqlite3_vfs *pVfs, void *pHandle){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_DLCLOSE);
  vfstrace_printf(pInfo, "%s.xDlClose()\n", pInfo->zVfsName);
  pRoot->xDlClose(pRoot, pHandle);
}

/*
** Populate the buffer pointed to by zBufOut with nByte bytes of 
** random data.
*/
static int vfstraceRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_RAND);
  vfstrace_printf(pInfo, "%s.xRandomness(%d)\n", pInfo->zVfsName, nByte);
  return pRoot->xRandomness(pRoot, nByte, zBufOut);
}

/*
** Sleep for nMicro microseconds. Return the number of microseconds 
** actually slept.
*/
static int vfstraceSleep(sqlite3_vfs *pVfs, int nMicro){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_SLEEP);
  vfstrace_printf(pInfo, "%s.xSleep(%d)\n", pInfo->zVfsName, nMicro);
  return pRoot->xSleep(pRoot, nMicro);
}

/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int vfstraceCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_CURTIME);
  vfstrace_printf(pInfo, "%s.xCurrentTime()", pInfo->zVfsName);
  rc = pRoot->xCurrentTime(pRoot, pTimeOut);
  vfstrace_printf(pInfo, " -> %.17g\n", *pTimeOut);
  return rc;
}
static int vfstraceCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_CURTIME);
  vfstrace_printf(pInfo, "%s.xCurrentTimeInt64()", pInfo->zVfsName);
  rc = pRoot->xCurrentTimeInt64(pRoot, pTimeOut);
  vfstrace_printf(pInfo, " -> %lld\n", *pTimeOut);
  return rc;
}

/*
** Return the most recent error code and message
*/
static int vfstraceGetLastError(sqlite3_vfs *pVfs, int nErr, char *zErr){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_LASTERR);
  vfstrace_printf(pInfo, "%s.xGetLastError(%d,zBuf)", pInfo->zVfsName, nErr);
  if( nErr ) zErr[0] = 0;
  rc = pRoot->xGetLastError(pRoot, nErr, zErr);
  vfstrace_printf(pInfo, " -> zBuf[] = \"%s\", rc = %d\n", nErr?zErr:"", rc);
  return rc;
}

/*
** Override system calls.
*/
static int vfstraceSetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_syscall_ptr pFunc
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xSetSystemCall(pRoot, zName, pFunc);
}
static sqlite3_syscall_ptr vfstraceGetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xGetSystemCall(pRoot, zName);
}
static const char *vfstraceNextSystemCall(sqlite3_vfs *pVfs, const char *zName){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xNextSystemCall(pRoot, zName);
}


/*
** Clients invoke this routine to construct a new trace-vfs shim.
**
** Return SQLITE_OK on success.  
**
** SQLITE_NOMEM is returned in the case of a memory allocation error.
** SQLITE_NOTFOUND is returned if zOldVfsName does not exist.
*/
int vfstrace_register(
   const char *zTraceName,           /* Name of the newly constructed VFS */
   const char *zOldVfsName,          /* Name of the underlying VFS */
   int (*xOut)(const char*,void*),   /* Output routine.  ex: fputs */
   void *pOutArg,                    /* 2nd argument to xOut.  ex: stderr */
   int makeDefault                   /* True to make the new VFS the default */
){
  sqlite3_vfs *pNew;
  sqlite3_vfs *pRoot;
  vfstrace_info *pInfo;
  size_t nName;
  size_t nByte;

  pRoot = sqlite3_vfs_find(zOldVfsName);
  if( pRoot==0 ) return SQLITE_NOTFOUND;
  nName = strlen(zTraceName);
  nByte = sizeof(*pNew) + sizeof(*pInfo) + nName + 1;
  pNew = sqlite3_malloc64( nByte );
  if( pNew==0 ) return SQLITE_NOMEM;
  memset(pNew, 0, nByte);
  pInfo = (vfstrace_info*)&pNew[1];
  pNew->iVersion = pRoot->iVersion;
  pNew->szOsFile = pRoot->szOsFile + sizeof(vfstrace_file);
  pNew->mxPathname = pRoot->mxPathname;
  pNew->zName = (char*)&pInfo[1];
  memcpy((char*)&pInfo[1], zTraceName, nName+1);
  pNew->pAppData = pInfo;
  pNew->xOpen = vfstraceOpen;
  pNew->xDelete = vfstraceDelete;
  pNew->xAccess = vfstraceAccess;
  pNew->xFullPathname = vfstraceFullPathname;
  pNew->xDlOpen = pRoot->xDlOpen==0 ? 0 : vfstraceDlOpen;
  pNew->xDlError = pRoot->xDlError==0 ? 0 : vfstraceDlError;
  pNew->xDlSym = pRoot->xDlSym==0 ? 0 : vfstraceDlSym;
  pNew->xDlClose = pRoot->xDlClose==0 ? 0 : vfstraceDlClose;
  pNew->xRandomness = vfstraceRandomness;
  pNew->xSleep = vfstraceSleep;
  pNew->xCurrentTime = vfstraceCurrentTime;
  pNew->xGetLastError = pRoot->xGetLastError==0 ? 0 : vfstraceGetLastError;
  if( pNew->iVersion>=2 ){
    pNew->xCurrentTimeInt64 = pRoot->xCurrentTimeInt64==0 ? 0 :
                                   vfstraceCurrentTimeInt64;
    if( pNew->iVersion>=3 ){
      pNew->xSetSystemCall = pRoot->xSetSystemCall==0 ? 0 : 
                                   vfstraceSetSystemCall;
      pNew->xGetSystemCall = pRoot->xGetSystemCall==0 ? 0 : 
                                   vfstraceGetSystemCall;
      pNew->xNextSystemCall = pRoot->xNextSystemCall==0 ? 0 : 
                                   vfstraceNextSystemCall;
    }
  }
  pInfo->pRootVfs = pRoot;
  pInfo->xOut = xOut;
  pInfo->pOutArg = pOutArg;
  pInfo->zVfsName = pNew->zName;
  pInfo->pTraceVfs = pNew;
  pInfo->mTrace = 0xffffffff;
  pInfo->bOn = 1;
  vfstrace_printf(pInfo, "%s.enabled_for(\"%s\")\n",
       pInfo->zVfsName, pRoot->zName);
  return sqlite3_vfs_register(pNew, makeDefault);
}

/*
** Look for the named VFS.  If it is a TRACEVFS, then unregister it
** and delete it.
*/
void vfstrace_unregister(const char *zTraceName){
  sqlite3_vfs *pVfs = sqlite3_vfs_find(zTraceName);
  if( pVfs==0 ) return;
  if( pVfs->xOpen!=vfstraceOpen ) return;
  sqlite3_vfs_unregister(pVfs);
  sqlite3_free(pVfs);
}

/************************* End ext/misc/vfstrace.c ********************/

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_ENABLE_DBPAGE_VTAB)
#define SQLITE_SHELL_HAVE_RECOVER 1
#else
#define SQLITE_SHELL_HAVE_RECOVER 0
#endif
#if SQLITE_SHELL_HAVE_RECOVER
/************************* Begin ext/recover/sqlite3recover.h ******************/
/*
** 2022-08-27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains the public interface to the "recover" extension -
** an SQLite extension designed to recover data from corrupted database
** files.
*/

/*
** OVERVIEW:
**
** To use the API to recover data from a corrupted database, an
** application:
**
**   1) Creates an sqlite3_recover handle by calling either
**      sqlite3_recover_init() or sqlite3_recover_init_sql().
**
**   2) Configures the new handle using one or more calls to
**      sqlite3_recover_config().
**
**   3) Executes the recovery by repeatedly calling sqlite3_recover_step() on
**      the handle until it returns something other than SQLITE_OK. If it
**      returns SQLITE_DONE, then the recovery operation completed without 
**      error. If it returns some other non-SQLITE_OK value, then an error 
**      has occurred.
**
**   4) Retrieves any error code and English language error message using the
**      sqlite3_recover_errcode() and sqlite3_recover_errmsg() APIs,
**      respectively.
**
**   5) Destroys the sqlite3_recover handle and frees all resources
**      using sqlite3_recover_finish().
**
** The application may abandon the recovery operation at any point 
** before it is finished by passing the sqlite3_recover handle to
** sqlite3_recover_finish(). This is not an error, but the final state
** of the output database, or the results of running the partial script
** delivered to the SQL callback, are undefined.
*/

#ifndef _SQLITE_RECOVER_H
#define _SQLITE_RECOVER_H

/* #include "sqlite3.h" */

#ifdef __cplusplus
extern "C" {
#endif

/*
** An instance of the sqlite3_recover object represents a recovery
** operation in progress.
**
** Constructors:
**
**    sqlite3_recover_init()
**    sqlite3_recover_init_sql()
**
** Destructor:
**
**    sqlite3_recover_finish()
**
** Methods:
**
**    sqlite3_recover_config()
**    sqlite3_recover_errcode()
**    sqlite3_recover_errmsg()
**    sqlite3_recover_run()
**    sqlite3_recover_step()
*/
typedef struct sqlite3_recover sqlite3_recover;

/* 
** These two APIs attempt to create and return a new sqlite3_recover object.
** In both cases the first two arguments identify the (possibly
** corrupt) database to recover data from. The first argument is an open
** database handle and the second the name of a database attached to that
** handle (i.e. "main", "temp" or the name of an attached database).
**
** If sqlite3_recover_init() is used to create the new sqlite3_recover
** handle, then data is recovered into a new database, identified by
** string parameter zUri. zUri may be an absolute or relative file path,
** or may be an SQLite URI. If the identified database file already exists,
** it is overwritten.
**
** If sqlite3_recover_init_sql() is invoked, then any recovered data will
** be returned to the user as a series of SQL statements. Executing these
** SQL statements results in the same database as would have been created
** had sqlite3_recover_init() been used. For each SQL statement in the
** output, the callback function passed as the third argument (xSql) is 
** invoked once. The first parameter is a passed a copy of the fourth argument
** to this function (pCtx) as its first parameter, and a pointer to a
** nul-terminated buffer containing the SQL statement formated as UTF-8 as 
** the second. If the xSql callback returns any value other than SQLITE_OK,
** then processing is immediately abandoned and the value returned used as
** the recover handle error code (see below).
**
** If an out-of-memory error occurs, NULL may be returned instead of
** a valid handle. In all other cases, it is the responsibility of the
** application to avoid resource leaks by ensuring that
** sqlite3_recover_finish() is called on all allocated handles.
*/
sqlite3_recover *sqlite3_recover_init(
  sqlite3* db, 
  const char *zDb, 
  const char *zUri
);
sqlite3_recover *sqlite3_recover_init_sql(
  sqlite3* db, 
  const char *zDb, 
  int (*xSql)(void*, const char*),
  void *pCtx
);

/*
** Configure an sqlite3_recover object that has just been created using
** sqlite3_recover_init() or sqlite3_recover_init_sql(). This function
** may only be called before the first call to sqlite3_recover_step()
** or sqlite3_recover_run() on the object.
**
** The second argument passed to this function must be one of the
** SQLITE_RECOVER_* symbols defined below. Valid values for the third argument
** depend on the specific SQLITE_RECOVER_* symbol in use.
**
** SQLITE_OK is returned if the configuration operation was successful,
** or an SQLite error code otherwise.
*/
int sqlite3_recover_config(sqlite3_recover*, int op, void *pArg);

/*
** SQLITE_RECOVER_LOST_AND_FOUND:
**   The pArg argument points to a string buffer containing the name
**   of a "lost-and-found" table in the output database, or NULL. If
**   the argument is non-NULL and the database contains seemingly
**   valid pages that cannot be associated with any table in the
**   recovered part of the schema, data is extracted from these
**   pages to add to the lost-and-found table.
**
** SQLITE_RECOVER_FREELIST_CORRUPT:
**   The pArg value must actually be a pointer to a value of type
**   int containing value 0 or 1 cast as a (void*). If this option is set
**   (argument is 1) and a lost-and-found table has been configured using
**   SQLITE_RECOVER_LOST_AND_FOUND, then is assumed that the freelist is 
**   corrupt and an attempt is made to recover records from pages that
**   appear to be linked into the freelist. Otherwise, pages on the freelist
**   are ignored. Setting this option can recover more data from the
**   database, but often ends up "recovering" deleted records. The default 
**   value is 0 (clear).
**
** SQLITE_RECOVER_ROWIDS:
**   The pArg value must actually be a pointer to a value of type
**   int containing value 0 or 1 cast as a (void*). If this option is set
**   (argument is 1), then an attempt is made to recover rowid values
**   that are not also INTEGER PRIMARY KEY values. If this option is
**   clear, then new rowids are assigned to all recovered rows. The
**   default value is 1 (set).
**
** SQLITE_RECOVER_SLOWINDEXES:
**   The pArg value must actually be a pointer to a value of type
**   int containing value 0 or 1 cast as a (void*). If this option is clear
**   (argument is 0), then when creating an output database, the recover 
**   module creates and populates non-UNIQUE indexes right at the end of the
**   recovery operation - after all recoverable data has been inserted
**   into the new database. This is faster overall, but means that the
**   final call to sqlite3_recover_step() for a recovery operation may
**   be need to create a large number of indexes, which may be very slow.
**
**   Or, if this option is set (argument is 1), then non-UNIQUE indexes
**   are created in the output database before it is populated with 
**   recovered data. This is slower overall, but avoids the slow call
**   to sqlite3_recover_step() at the end of the recovery operation.
**
**   The default option value is 0.
*/
#define SQLITE_RECOVER_LOST_AND_FOUND   1
#define SQLITE_RECOVER_FREELIST_CORRUPT 2
#define SQLITE_RECOVER_ROWIDS           3
#define SQLITE_RECOVER_SLOWINDEXES      4

/*
** Perform a unit of work towards the recovery operation. This function 
** must normally be called multiple times to complete database recovery.
**
** If no error occurs but the recovery operation is not completed, this
** function returns SQLITE_OK. If recovery has been completed successfully
** then SQLITE_DONE is returned. If an error has occurred, then an SQLite
** error code (e.g. SQLITE_IOERR or SQLITE_NOMEM) is returned. It is not
** considered an error if some or all of the data cannot be recovered
** due to database corruption.
**
** Once sqlite3_recover_step() has returned a value other than SQLITE_OK,
** all further such calls on the same recover handle are no-ops that return
** the same non-SQLITE_OK value.
*/
int sqlite3_recover_step(sqlite3_recover*);

/* 
** Run the recovery operation to completion. Return SQLITE_OK if successful,
** or an SQLite error code otherwise. Calling this function is the same
** as executing:
**
**     while( SQLITE_OK==sqlite3_recover_step(p) );
**     return sqlite3_recover_errcode(p);
*/
int sqlite3_recover_run(sqlite3_recover*);

/*
** If an error has been encountered during a prior call to
** sqlite3_recover_step(), then this function attempts to return a 
** pointer to a buffer containing an English language explanation of 
** the error. If no error message is available, or if an out-of memory 
** error occurs while attempting to allocate a buffer in which to format
** the error message, NULL is returned.
**
** The returned buffer remains valid until the sqlite3_recover handle is
** destroyed using sqlite3_recover_finish().
*/
const char *sqlite3_recover_errmsg(sqlite3_recover*);

/*
** If this function is called on an sqlite3_recover handle after
** an error occurs, an SQLite error code is returned. Otherwise, SQLITE_OK.
*/
int sqlite3_recover_errcode(sqlite3_recover*);

/* 
** Clean up a recovery object created by a call to sqlite3_recover_init().
** The results of using a recovery object with any API after it has been
** passed to this function are undefined.
**
** This function returns the same value as sqlite3_recover_errcode().
*/
int sqlite3_recover_finish(sqlite3_recover*);


#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif /* ifndef _SQLITE_RECOVER_H */

/************************* End ext/recover/sqlite3recover.h ********************/
# ifndef SQLITE_HAVE_SQLITE3R
/************************* Begin ext/recover/dbdata.c ******************/
/*
** 2019-04-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains an implementation of two eponymous virtual tables,
** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the
** "sqlite_dbpage" eponymous virtual table be available.
**
** SQLITE_DBDATA:
**   sqlite_dbdata is used to extract data directly from a database b-tree
**   page and its associated overflow pages, bypassing the b-tree layer.
**   The table schema is equivalent to:
**
**     CREATE TABLE sqlite_dbdata(
**       pgno INTEGER,
**       cell INTEGER,
**       field INTEGER,
**       value ANY,
**       schema TEXT HIDDEN
**     );
**
**   IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE
**   FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND
**   "schema".
**
**   Each page of the database is inspected. If it cannot be interpreted as
**   a b-tree page, or if it is a b-tree page containing 0 entries, the
**   sqlite_dbdata table contains no rows for that page.  Otherwise, the
**   table contains one row for each field in the record associated with
**   each cell on the page. For intkey b-trees, the key value is stored in
**   field -1.
**
**   For example, for the database:
**
**     CREATE TABLE t1(a, b);     -- root page is page 2
**     INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five');
**     INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten');
**
**   the sqlite_dbdata table contains, as well as from entries related to 
**   page 1, content equivalent to:
**
**     INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES
**         (2, 0, -1, 5     ),
**         (2, 0,  0, 'v'   ),
**         (2, 0,  1, 'five'),
**         (2, 1, -1, 10    ),
**         (2, 1,  0, 'x'   ),
**         (2, 1,  1, 'ten' );
**
**   If database corruption is encountered, this module does not report an
**   error. Instead, it attempts to extract as much data as possible and
**   ignores the corruption.
**
** SQLITE_DBPTR:
**   The sqlite_dbptr table has the following schema:
**
**     CREATE TABLE sqlite_dbptr(
**       pgno INTEGER,
**       child INTEGER,
**       schema TEXT HIDDEN
**     );
**
**   It contains one entry for each b-tree pointer between a parent and
**   child page in the database.
*/

#if !defined(SQLITEINT_H) 
/* #include "sqlite3.h" */
/* #include "sqlite3ext.h" */

/* typedef unsigned char u8; */
/* typedef unsigned int u32; */

#endif
#include <string.h>
#include <assert.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

#define DBDATA_PADDING_BYTES 100 

typedef struct DbdataTable DbdataTable;
typedef struct DbdataCursor DbdataCursor;
typedef struct DbdataBuffer DbdataBuffer;

/*
** Buffer type.
*/
struct DbdataBuffer {
  u8 *aBuf;
  sqlite3_int64 nBuf;
};

/* Cursor object */
struct DbdataCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_stmt *pStmt;            /* For fetching database pages */

  int iPgno;                      /* Current page number */
  u8 *aPage;                      /* Buffer containing page */
  int nPage;                      /* Size of aPage[] in bytes */
  int nCell;                      /* Number of cells on aPage[] */
  int iCell;                      /* Current cell number */
  int bOnePage;                   /* True to stop after one page */
  int szDb;
  sqlite3_int64 iRowid;

  /* Only for the sqlite_dbdata table */
  DbdataBuffer rec;
  sqlite3_int64 nRec;             /* Size of pRec[] in bytes */
  sqlite3_int64 nHdr;             /* Size of header in bytes */
  int iField;                     /* Current field number */
  u8 *pHdrPtr;
  u8 *pPtr;
  u32 enc;                        /* Text encoding */
  
  sqlite3_int64 iIntkey;          /* Integer key value */
};

/* Table object */
struct DbdataTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The database connection */
  sqlite3_stmt *pStmt;            /* For fetching database pages */
  int bPtr;                       /* True for sqlite3_dbptr table */
};

/* Column and schema definitions for sqlite_dbdata */
#define DBDATA_COLUMN_PGNO        0
#define DBDATA_COLUMN_CELL        1
#define DBDATA_COLUMN_FIELD       2
#define DBDATA_COLUMN_VALUE       3
#define DBDATA_COLUMN_SCHEMA      4
#define DBDATA_SCHEMA             \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  cell INTEGER,"           \
      "  field INTEGER,"          \
      "  value ANY,"              \
      "  schema TEXT HIDDEN"      \
      ")"

/* Column and schema definitions for sqlite_dbptr */
#define DBPTR_COLUMN_PGNO         0
#define DBPTR_COLUMN_CHILD        1
#define DBPTR_COLUMN_SCHEMA       2
#define DBPTR_SCHEMA              \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  child INTEGER,"          \
      "  schema TEXT HIDDEN"      \
      ")"

/*
** Ensure the buffer passed as the first argument is at least nMin bytes
** in size. If an error occurs while attempting to resize the buffer,
** SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.
*/
static int dbdataBufferSize(DbdataBuffer *pBuf, sqlite3_int64 nMin){
  if( nMin>pBuf->nBuf ){
    sqlite3_int64 nNew = nMin+16384;
    u8 *aNew = (u8*)sqlite3_realloc64(pBuf->aBuf, nNew);

    if( aNew==0 ) return SQLITE_NOMEM;
    pBuf->aBuf = aNew;
    pBuf->nBuf = nNew;
  }
  return SQLITE_OK;
}

/*
** Release the allocation managed by buffer pBuf.
*/
static void dbdataBufferFree(DbdataBuffer *pBuf){
  sqlite3_free(pBuf->aBuf);
  memset(pBuf, 0, sizeof(*pBuf));
}

/*
** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual 
** table.
*/
static int dbdataConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  DbdataTable *pTab = 0;
  int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA);

  (void)argc;
  (void)argv;
  (void)pzErr;
  sqlite3_vtab_config(db, SQLITE_VTAB_USES_ALL_SCHEMAS);
  if( rc==SQLITE_OK ){
    pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable));
    if( pTab==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pTab, 0, sizeof(DbdataTable));
      pTab->db = db;
      pTab->bPtr = (pAux!=0);
    }
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table.
*/
static int dbdataDisconnect(sqlite3_vtab *pVtab){
  DbdataTable *pTab = (DbdataTable*)pVtab;
  if( pTab ){
    sqlite3_finalize(pTab->pStmt);
    sqlite3_free(pVtab);
  }
  return SQLITE_OK;
}

/*
** This function interprets two types of constraints:
**
**       schema=?
**       pgno=?
**
** If neither are present, idxNum is set to 0. If schema=? is present,
** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit
** in idxNum is set.
**
** If both parameters are present, schema is in position 0 and pgno in
** position 1.
*/
static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){
  DbdataTable *pTab = (DbdataTable*)tab;
  int i;
  int iSchema = -1;
  int iPgno = -1;
  int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA);

  for(i=0; i<pIdx->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdx->aConstraint[i];
    if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      if( p->iColumn==colSchema ){
        if( p->usable==0 ) return SQLITE_CONSTRAINT;
        iSchema = i;
      }
      if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){
        iPgno = i;
      }
    }
  }

  if( iSchema>=0 ){
    pIdx->aConstraintUsage[iSchema].argvIndex = 1;
    pIdx->aConstraintUsage[iSchema].omit = 1;
  }
  if( iPgno>=0 ){
    pIdx->aConstraintUsage[iPgno].argvIndex = 1 + (iSchema>=0);
    pIdx->aConstraintUsage[iPgno].omit = 1;
    pIdx->estimatedCost = 100;
    pIdx->estimatedRows =  50;

    if( pTab->bPtr==0 && pIdx->nOrderBy && pIdx->aOrderBy[0].desc==0 ){
      int iCol = pIdx->aOrderBy[0].iColumn;
      if( pIdx->nOrderBy==1 ){
        pIdx->orderByConsumed = (iCol==0 || iCol==1);
      }else if( pIdx->nOrderBy==2 && pIdx->aOrderBy[1].desc==0 && iCol==0 ){
        pIdx->orderByConsumed = (pIdx->aOrderBy[1].iColumn==1);
      }
    }

  }else{
    pIdx->estimatedCost = 100000000;
    pIdx->estimatedRows = 1000000000;
  }
  pIdx->idxNum = (iSchema>=0 ? 0x01 : 0x00) | (iPgno>=0 ? 0x02 : 0x00);
  return SQLITE_OK;
}

/*
** Open a new sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  DbdataCursor *pCsr;

  pCsr = (DbdataCursor*)sqlite3_malloc64(sizeof(DbdataCursor));
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }else{
    memset(pCsr, 0, sizeof(DbdataCursor));
    pCsr->base.pVtab = pVTab;
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

/*
** Restore a cursor object to the state it was in when first allocated 
** by dbdataOpen().
*/
static void dbdataResetCursor(DbdataCursor *pCsr){
  DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab);
  if( pTab->pStmt==0 ){
    pTab->pStmt = pCsr->pStmt;
  }else{
    sqlite3_finalize(pCsr->pStmt);
  }
  pCsr->pStmt = 0;
  pCsr->iPgno = 1;
  pCsr->iCell = 0;
  pCsr->iField = 0;
  pCsr->bOnePage = 0;
  sqlite3_free(pCsr->aPage);
  dbdataBufferFree(&pCsr->rec);
  pCsr->aPage = 0;
  pCsr->nRec = 0;
}

/*
** Close an sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataClose(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  dbdataResetCursor(pCsr);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/* 
** Utility methods to decode 16 and 32-bit big-endian unsigned integers. 
*/
static u32 get_uint16(unsigned char *a){
  return (a[0]<<8)|a[1];
}
static u32 get_uint32(unsigned char *a){
  return ((u32)a[0]<<24)
       | ((u32)a[1]<<16)
       | ((u32)a[2]<<8)
       | ((u32)a[3]);
}

/*
** Load page pgno from the database via the sqlite_dbpage virtual table.
** If successful, set (*ppPage) to point to a buffer containing the page
** data, (*pnPage) to the size of that buffer in bytes and return
** SQLITE_OK. In this case it is the responsibility of the caller to
** eventually free the buffer using sqlite3_free().
**
** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and
** return an SQLite error code.
*/
static int dbdataLoadPage(
  DbdataCursor *pCsr,             /* Cursor object */
  u32 pgno,                       /* Page number of page to load */
  u8 **ppPage,                    /* OUT: pointer to page buffer */
  int *pnPage                     /* OUT: Size of (*ppPage) in bytes */
){
  int rc2;
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = pCsr->pStmt;

  *ppPage = 0;
  *pnPage = 0;
  if( pgno>0 ){
    sqlite3_bind_int64(pStmt, 2, pgno);
    if( SQLITE_ROW==sqlite3_step(pStmt) ){
      int nCopy = sqlite3_column_bytes(pStmt, 0);
      if( nCopy>0 ){
        u8 *pPage;
        pPage = (u8*)sqlite3_malloc64(nCopy + DBDATA_PADDING_BYTES);
        if( pPage==0 ){
          rc = SQLITE_NOMEM;
        }else{
          const u8 *pCopy = sqlite3_column_blob(pStmt, 0);
          memcpy(pPage, pCopy, nCopy);
          memset(&pPage[nCopy], 0, DBDATA_PADDING_BYTES);
        }
        *ppPage = pPage;
        *pnPage = nCopy;
      }
    }
    rc2 = sqlite3_reset(pStmt);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  return rc;
}

/*
** Read a varint.  Put the value in *pVal and return the number of bytes.
*/
static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_uint64 u = 0;
  int i;
  for(i=0; i<8; i++){
    u = (u<<7) + (z[i]&0x7f);
    if( (z[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; }
  }
  u = (u<<8) + (z[i]&0xff);
  *pVal = (sqlite3_int64)u;
  return 9;
}

/*
** Like dbdataGetVarint(), but set the output to 0 if it is less than 0
** or greater than 0xFFFFFFFF. This can be used for all varints in an
** SQLite database except for key values in intkey tables.
*/
static int dbdataGetVarintU32(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_int64 val;
  int nRet = dbdataGetVarint(z, &val);
  if( val<0 || val>0xFFFFFFFF ) val = 0;
  *pVal = val;
  return nRet;
}

/*
** Return the number of bytes of space used by an SQLite value of type
** eType.
*/
static int dbdataValueBytes(int eType){
  switch( eType ){
    case 0: case 8: case 9:
    case 10: case 11:
      return 0;
    case 1:
      return 1;
    case 2:
      return 2;
    case 3:
      return 3;
    case 4:
      return 4;
    case 5:
      return 6;
    case 6:
    case 7:
      return 8;
    default:
      if( eType>0 ){
        return ((eType-12) / 2);
      }
      return 0;
  }
}

/*
** Load a value of type eType from buffer pData and use it to set the
** result of context object pCtx.
*/
static void dbdataValue(
  sqlite3_context *pCtx, 
  u32 enc,
  int eType, 
  u8 *pData,
  sqlite3_int64 nData
){
  if( eType>=0 ){
    if( dbdataValueBytes(eType)<=nData ){
      switch( eType ){
        case 0: 
        case 10: 
        case 11: 
          sqlite3_result_null(pCtx);
          break;
        
        case 8: 
          sqlite3_result_int(pCtx, 0);
          break;
        case 9:
          sqlite3_result_int(pCtx, 1);
          break;
    
        case 1: case 2: case 3: case 4: case 5: case 6: case 7: {
          sqlite3_uint64 v = (signed char)pData[0];
          pData++;
          switch( eType ){
            case 7:
            case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
            case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
            case 4:  v = (v<<8) + pData[0];  pData++;
            case 3:  v = (v<<8) + pData[0];  pData++;
            case 2:  v = (v<<8) + pData[0];  pData++;
          }
    
          if( eType==7 ){
            double r;
            memcpy(&r, &v, sizeof(r));
            sqlite3_result_double(pCtx, r);
          }else{
            sqlite3_result_int64(pCtx, (sqlite3_int64)v);
          }
          break;
        }
    
        default: {
          int n = ((eType-12) / 2);
          if( eType % 2 ){
            switch( enc ){
  #ifndef SQLITE_OMIT_UTF16
              case SQLITE_UTF16BE:
                sqlite3_result_text16be(pCtx, (void*)pData, n, SQLITE_TRANSIENT);
                break;
              case SQLITE_UTF16LE:
                sqlite3_result_text16le(pCtx, (void*)pData, n, SQLITE_TRANSIENT);
                break;
  #endif
              default:
                sqlite3_result_text(pCtx, (char*)pData, n, SQLITE_TRANSIENT);
                break;
            }
          }else{
            sqlite3_result_blob(pCtx, pData, n, SQLITE_TRANSIENT);
          }
        }
      }
    }else{
      if( eType==7 ){
        sqlite3_result_double(pCtx, 0.0);
      }else if( eType<7 ){
        sqlite3_result_int(pCtx, 0);
      }else if( eType%2 ){
        sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
      }else{
        sqlite3_result_blob(pCtx, "", 0, SQLITE_STATIC);
      }
    }
  }
}

/* This macro is a copy of the MX_CELL() macro in the SQLite core. Given
** a page-size, it returns the maximum number of cells that may be present
** on the page.  */
#define DBDATA_MX_CELL(pgsz) ((pgsz-8)/6)

/* Maximum number of fields that may appear in a single record. This is
** the "hard-limit", according to comments in sqliteLimit.h. */
#define DBDATA_MX_FIELD 32676

/*
** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry.
*/
static int dbdataNext(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;

  pCsr->iRowid++;
  while( 1 ){
    int rc;
    int iOff = (pCsr->iPgno==1 ? 100 : 0);
    int bNextPage = 0;

    if( pCsr->aPage==0 ){
      while( 1 ){
        if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK;
        rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage);
        if( rc!=SQLITE_OK ) return rc;
        if( pCsr->aPage && pCsr->nPage>=256 ) break;
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }

      assert( iOff+3+2<=pCsr->nPage );
      pCsr->iCell = pTab->bPtr ? -2 : 0;
      pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]);
      if( pCsr->nCell>DBDATA_MX_CELL(pCsr->nPage) ){
        pCsr->nCell = DBDATA_MX_CELL(pCsr->nPage);
      }
    }

    if( pTab->bPtr ){
      if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){
        pCsr->iCell = pCsr->nCell;
      }
      pCsr->iCell++;
      if( pCsr->iCell>=pCsr->nCell ){
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        return SQLITE_OK;
      }
    }else{
      /* If there is no record loaded, load it now. */
      assert( pCsr->rec.aBuf!=0 || pCsr->nRec==0 );
      if( pCsr->nRec==0 ){
        int bHasRowid = 0;
        int nPointer = 0;
        sqlite3_int64 nPayload = 0;
        sqlite3_int64 nHdr = 0;
        int iHdr;
        int U, X;
        int nLocal;
  
        switch( pCsr->aPage[iOff] ){
          case 0x02:
            nPointer = 4;
            break;
          case 0x0a:
            break;
          case 0x0d:
            bHasRowid = 1;
            break;
          default:
            /* This is not a b-tree page with records on it. Continue. */
            pCsr->iCell = pCsr->nCell;
            break;
        }

        if( pCsr->iCell>=pCsr->nCell ){
          bNextPage = 1;
        }else{
          int iCellPtr = iOff + 8 + nPointer + pCsr->iCell*2;
  
          if( iCellPtr>pCsr->nPage ){
            bNextPage = 1;
          }else{
            iOff = get_uint16(&pCsr->aPage[iCellPtr]);
          }
    
          /* For an interior node cell, skip past the child-page number */
          iOff += nPointer;
    
          /* Load the "byte of payload including overflow" field */
          if( bNextPage || iOff>pCsr->nPage || iOff<=iCellPtr ){
            bNextPage = 1;
          }else{
            iOff += dbdataGetVarintU32(&pCsr->aPage[iOff], &nPayload);
            if( nPayload>0x7fffff00 ) nPayload &= 0x3fff;
            if( nPayload==0 ) nPayload = 1;
          }
    
          /* If this is a leaf intkey cell, load the rowid */
          if( bHasRowid && !bNextPage && iOff<pCsr->nPage ){
            iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey);
          }
    
          /* Figure out how much data to read from the local page */
          U = pCsr->nPage;
          if( bHasRowid ){
            X = U-35;
          }else{
            X = ((U-12)*64/255)-23;
          }
          if( nPayload<=X ){
            nLocal = nPayload;
          }else{
            int M, K;
            M = ((U-12)*32/255)-23;
            K = M+((nPayload-M)%(U-4));
            if( K<=X ){
              nLocal = K;
            }else{
              nLocal = M;
            }
          }

          if( bNextPage || nLocal+iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{

            /* Allocate space for payload. And a bit more to catch small buffer
            ** overruns caused by attempting to read a varint or similar from 
            ** near the end of a corrupt record.  */
            rc = dbdataBufferSize(&pCsr->rec, nPayload+DBDATA_PADDING_BYTES);
            if( rc!=SQLITE_OK ) return rc;
            assert( pCsr->rec.aBuf!=0 );
            assert( nPayload!=0 );

            /* Load the nLocal bytes of payload */
            memcpy(pCsr->rec.aBuf, &pCsr->aPage[iOff], nLocal);
            iOff += nLocal;

            /* Load content from overflow pages */
            if( nPayload>nLocal ){
              sqlite3_int64 nRem = nPayload - nLocal;
              u32 pgnoOvfl = get_uint32(&pCsr->aPage[iOff]);
              while( nRem>0 ){
                u8 *aOvfl = 0;
                int nOvfl = 0;
                int nCopy;
                rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl);
                assert( rc!=SQLITE_OK || aOvfl==0 || nOvfl==pCsr->nPage );
                if( rc!=SQLITE_OK ) return rc;
                if( aOvfl==0 ) break;

                nCopy = U-4;
                if( nCopy>nRem ) nCopy = nRem;
                memcpy(&pCsr->rec.aBuf[nPayload-nRem], &aOvfl[4], nCopy);
                nRem -= nCopy;

                pgnoOvfl = get_uint32(aOvfl);
                sqlite3_free(aOvfl);
              }
              nPayload -= nRem;
            }
            memset(&pCsr->rec.aBuf[nPayload], 0, DBDATA_PADDING_BYTES);
            pCsr->nRec = nPayload;
    
            iHdr = dbdataGetVarintU32(pCsr->rec.aBuf, &nHdr);
            if( nHdr>nPayload ) nHdr = 0;
            pCsr->nHdr = nHdr;
            pCsr->pHdrPtr = &pCsr->rec.aBuf[iHdr];
            pCsr->pPtr = &pCsr->rec.aBuf[pCsr->nHdr];
            pCsr->iField = (bHasRowid ? -1 : 0);
          }
        }
      }else{
        pCsr->iField++;
        if( pCsr->iField>0 ){
          sqlite3_int64 iType;
          if( pCsr->pHdrPtr>=&pCsr->rec.aBuf[pCsr->nRec] 
           || pCsr->iField>=DBDATA_MX_FIELD
          ){
            bNextPage = 1;
          }else{
            int szField = 0;
            pCsr->pHdrPtr += dbdataGetVarintU32(pCsr->pHdrPtr, &iType);
            szField = dbdataValueBytes(iType);
            if( (pCsr->nRec - (pCsr->pPtr - pCsr->rec.aBuf))<szField ){
              pCsr->pPtr = &pCsr->rec.aBuf[pCsr->nRec];
            }else{
              pCsr->pPtr += szField;
            }
          }
        }
      }

      if( bNextPage ){
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        pCsr->nRec = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        if( pCsr->iField<0 || pCsr->pHdrPtr<&pCsr->rec.aBuf[pCsr->nHdr] ){
          return SQLITE_OK;
        }

        /* Advance to the next cell. The next iteration of the loop will load
        ** the record and so on. */
        pCsr->nRec = 0;
        pCsr->iCell++;
      }
    }
  }

  assert( !"can't get here" );
  return SQLITE_OK;
}

/* 
** Return true if the cursor is at EOF.
*/
static int dbdataEof(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  return pCsr->aPage==0;
}

/*
** Return true if nul-terminated string zSchema ends in "()". Or false
** otherwise.
*/
static int dbdataIsFunction(const char *zSchema){
  size_t n = strlen(zSchema);
  if( n>2 && zSchema[n-2]=='(' && zSchema[n-1]==')' ){
    return (int)n-2;
  }
  return 0;
}

/* 
** Determine the size in pages of database zSchema (where zSchema is
** "main", "temp" or the name of an attached database) and set 
** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise,
** an SQLite error code.
*/
static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){
  DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab;
  char *zSql = 0;
  int rc, rc2;
  int nFunc = 0;
  sqlite3_stmt *pStmt = 0;

  if( (nFunc = dbdataIsFunction(zSchema))>0 ){
    zSql = sqlite3_mprintf("SELECT %.*s(0)", nFunc, zSchema);
  }else{
    zSql = sqlite3_mprintf("PRAGMA %Q.page_count", zSchema);
  }
  if( zSql==0 ) return SQLITE_NOMEM;

  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
    pCsr->szDb = sqlite3_column_int(pStmt, 0);
  }
  rc2 = sqlite3_finalize(pStmt);
  if( rc==SQLITE_OK ) rc = rc2;
  return rc;
}

/*
** Attempt to figure out the encoding of the database by retrieving page 1
** and inspecting the header field. If successful, set the pCsr->enc variable
** and return SQLITE_OK. Otherwise, return an SQLite error code.
*/
static int dbdataGetEncoding(DbdataCursor *pCsr){
  int rc = SQLITE_OK;
  int nPg1 = 0;
  u8 *aPg1 = 0;
  rc = dbdataLoadPage(pCsr, 1, &aPg1, &nPg1);
  if( rc==SQLITE_OK && nPg1>=(56+4) ){
    pCsr->enc = get_uint32(&aPg1[56]);
  }
  sqlite3_free(aPg1);
  return rc;
}


/* 
** xFilter method for sqlite_dbdata and sqlite_dbptr.
*/
static int dbdataFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  int rc = SQLITE_OK;
  const char *zSchema = "main";
  (void)idxStr;
  (void)argc;

  dbdataResetCursor(pCsr);
  assert( pCsr->iPgno==1 );
  if( idxNum & 0x01 ){
    zSchema = (const char*)sqlite3_value_text(argv[0]);
    if( zSchema==0 ) zSchema = "";
  }
  if( idxNum & 0x02 ){
    pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]);
    pCsr->bOnePage = 1;
  }else{
    rc = dbdataDbsize(pCsr, zSchema);
  }

  if( rc==SQLITE_OK ){
    int nFunc = 0;
    if( pTab->pStmt ){
      pCsr->pStmt = pTab->pStmt;
      pTab->pStmt = 0;
    }else if( (nFunc = dbdataIsFunction(zSchema))>0 ){
      char *zSql = sqlite3_mprintf("SELECT %.*s(?2)", nFunc, zSchema);
      if( zSql==0 ){
        rc = SQLITE_NOMEM;
      }else{
        rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
        sqlite3_free(zSql);
      }
    }else{
      rc = sqlite3_prepare_v2(pTab->db, 
          "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1,
          &pCsr->pStmt, 0
      );
    }
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_bind_text(pCsr->pStmt, 1, zSchema, -1, SQLITE_TRANSIENT);
  }

  /* Try to determine the encoding of the db by inspecting the header
  ** field on page 1. */
  if( rc==SQLITE_OK ){
    rc = dbdataGetEncoding(pCsr);
  }

  if( rc!=SQLITE_OK ){
    pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
  }

  if( rc==SQLITE_OK ){
    rc = dbdataNext(pCursor);
  }
  return rc;
}

/*
** Return a column for the sqlite_dbdata or sqlite_dbptr table.
*/
static int dbdataColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  if( pTab->bPtr ){
    switch( i ){
      case DBPTR_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBPTR_COLUMN_CHILD: {
        int iOff = pCsr->iPgno==1 ? 100 : 0;
        if( pCsr->iCell<0 ){
          iOff += 8;
        }else{
          iOff += 12 + pCsr->iCell*2;
          if( iOff>pCsr->nPage ) return SQLITE_OK;
          iOff = get_uint16(&pCsr->aPage[iOff]);
        }
        if( iOff<=pCsr->nPage ){
          sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff]));
        }
        break;
      }
    }
  }else{
    switch( i ){
      case DBDATA_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBDATA_COLUMN_CELL:
        sqlite3_result_int(ctx, pCsr->iCell);
        break;
      case DBDATA_COLUMN_FIELD:
        sqlite3_result_int(ctx, pCsr->iField);
        break;
      case DBDATA_COLUMN_VALUE: {
        if( pCsr->iField<0 ){
          sqlite3_result_int64(ctx, pCsr->iIntkey);
        }else if( &pCsr->rec.aBuf[pCsr->nRec] >= pCsr->pPtr ){
          sqlite3_int64 iType;
          dbdataGetVarintU32(pCsr->pHdrPtr, &iType);
          dbdataValue(
              ctx, pCsr->enc, iType, pCsr->pPtr, 
              &pCsr->rec.aBuf[pCsr->nRec] - pCsr->pPtr
          );
        }
        break;
      }
    }
  }
  return SQLITE_OK;
}

/* 
** Return the rowid for an sqlite_dbdata or sqlite_dptr table.
*/
static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}


/*
** Invoke this routine to register the "sqlite_dbdata" virtual table module
*/
static int sqlite3DbdataRegister(sqlite3 *db){
  static const sqlite3_module dbdata_module = {
    0,                            /* iVersion */
    0,                            /* xCreate */
    dbdataConnect,                /* xConnect */
    dbdataBestIndex,              /* xBestIndex */
    dbdataDisconnect,             /* xDisconnect */
    0,                            /* xDestroy */
    dbdataOpen,                   /* xOpen - open a cursor */
    dbdataClose,                  /* xClose - close a cursor */
    dbdataFilter,                 /* xFilter - configure scan constraints */
    dbdataNext,                   /* xNext - advance a cursor */
    dbdataEof,                    /* xEof - check for end of scan */
    dbdataColumn,                 /* xColumn - read data */
    dbdataRowid,                  /* xRowid - read data */
    0,                            /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
    0,                            /* xShadowName */
    0                             /* xIntegrity */
  };

  int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1);
  }
  return rc;
}

#ifdef _WIN32

#endif
int sqlite3_dbdata_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  (void)pzErrMsg;
  return sqlite3DbdataRegister(db);
}

#if !defined(_WIN32) && !defined(SQLITE_TEST) && !defined(SHELL_STRINGIFY_)
int sqlite3_extension_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return sqlite3DbdataRegister(db);
}
#endif
#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/************************* End ext/recover/dbdata.c ********************/
/************************* Begin ext/recover/sqlite3recover.c ******************/
/*
** 2022-08-27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
*/


/* #include "sqlite3recover.h" */
#include <assert.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Declaration for public API function in file dbdata.c. This may be called
** with NULL as the final two arguments to register the sqlite_dbptr and
** sqlite_dbdata virtual tables with a database handle.
*/
#ifdef _WIN32

#endif
int sqlite3_dbdata_init(sqlite3*, char**, const sqlite3_api_routines*);

/* typedef unsigned int u32; */
/* typedef unsigned char u8; */
/* typedef sqlite3_int64 i64; */

/*
** Work around C99 "flex-array" syntax for pre-C99 compilers, so as
** to avoid complaints from -fsanitize=strict-bounds.
*/
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
# define FLEXARRAY
#else
# define FLEXARRAY 1
#endif

typedef struct RecoverTable RecoverTable;
typedef struct RecoverColumn RecoverColumn;

/*
** When recovering rows of data that can be associated with table
** definitions recovered from the sqlite_schema table, each table is
** represented by an instance of the following object.
**
** iRoot:
**   The root page in the original database. Not necessarily (and usually
**   not) the same in the recovered database.
**
** zTab:
**   Name of the table.
**
** nCol/aCol[]:
**   aCol[] is an array of nCol columns. In the order in which they appear 
**   in the table.
**
** bIntkey:
**   Set to true for intkey tables, false for WITHOUT ROWID.
**
** iRowidBind:
**   Each column in the aCol[] array has associated with it the index of
**   the bind parameter its values will be bound to in the INSERT statement
**   used to construct the output database. If the table does has a rowid
**   but not an INTEGER PRIMARY KEY column, then iRowidBind contains the
**   index of the bind paramater to which the rowid value should be bound.
**   Otherwise, it contains -1. If the table does contain an INTEGER PRIMARY 
**   KEY column, then the rowid value should be bound to the index associated
**   with the column.
**
** pNext:
**   All RecoverTable objects used by the recovery operation are allocated
**   and populated as part of creating the recovered database schema in
**   the output database, before any non-schema data are recovered. They
**   are then stored in a singly-linked list linked by this variable beginning
**   at sqlite3_recover.pTblList.
*/
struct RecoverTable {
  u32 iRoot;                      /* Root page in original database */
  char *zTab;                     /* Name of table */
  int nCol;                       /* Number of columns in table */
  RecoverColumn *aCol;            /* Array of columns */
  int bIntkey;                    /* True for intkey, false for without rowid */
  int iRowidBind;                 /* If >0, bind rowid to INSERT here */
  RecoverTable *pNext;
};

/*
** Each database column is represented by an instance of the following object
** stored in the RecoverTable.aCol[] array of the associated table.
**
** iField:
**   The index of the associated field within database records. Or -1 if
**   there is no associated field (e.g. for virtual generated columns).
**
** iBind:
**   The bind index of the INSERT statement to bind this columns values
**   to. Or 0 if there is no such index (iff (iField<0)).
**
** bIPK:
**   True if this is the INTEGER PRIMARY KEY column.
**
** zCol:
**   Name of column.
**
** eHidden:
**   A RECOVER_EHIDDEN_* constant value (see below for interpretation of each).
*/
struct RecoverColumn {
  int iField;                     /* Field in record on disk */
  int iBind;                      /* Binding to use in INSERT */
  int bIPK;                       /* True for IPK column */
  char *zCol;
  int eHidden;
};

#define RECOVER_EHIDDEN_NONE    0      /* Normal database column */
#define RECOVER_EHIDDEN_HIDDEN  1      /* Column is __HIDDEN__ */
#define RECOVER_EHIDDEN_VIRTUAL 2      /* Virtual generated column */
#define RECOVER_EHIDDEN_STORED  3      /* Stored generated column */

/*
** Bitmap object used to track pages in the input database. Allocated
** and manipulated only by the following functions:
**
**     recoverBitmapAlloc()
**     recoverBitmapFree()
**     recoverBitmapSet()
**     recoverBitmapQuery()
**
** nPg:
**   Largest page number that may be stored in the bitmap. The range
**   of valid keys is 1 to nPg, inclusive.
**
** aElem[]:
**   Array large enough to contain a bit for each key. For key value
**   iKey, the associated bit is the bit (iKey%32) of aElem[iKey/32].
**   In other words, the following is true if bit iKey is set, or 
**   false if it is clear:
**
**       (aElem[iKey/32] & (1 << (iKey%32))) ? 1 : 0
*/
typedef struct RecoverBitmap RecoverBitmap;
struct RecoverBitmap {
  i64 nPg;                        /* Size of bitmap */
  u32 aElem[FLEXARRAY];           /* Array of 32-bit bitmasks */
};

/* Size in bytes of a RecoverBitmap object sufficient to cover 32 pages */
#define SZ_RECOVERBITMAP_32  (16)

/*
** State variables (part of the sqlite3_recover structure) used while
** recovering data for tables identified in the recovered schema (state
** RECOVER_STATE_WRITING).
*/
typedef struct RecoverStateW1 RecoverStateW1;
struct RecoverStateW1 {
  sqlite3_stmt *pTbls;
  sqlite3_stmt *pSel;
  sqlite3_stmt *pInsert;
  int nInsert;

  RecoverTable *pTab;             /* Table currently being written */
  int nMax;                       /* Max column count in any schema table */
  sqlite3_value **apVal;          /* Array of nMax values */
  int nVal;                       /* Number of valid entries in apVal[] */
  int bHaveRowid;
  i64 iRowid;
  i64 iPrevPage;
  int iPrevCell;
};

/*
** State variables (part of the sqlite3_recover structure) used while
** recovering data destined for the lost and found table (states
** RECOVER_STATE_LOSTANDFOUND[123]).
*/
typedef struct RecoverStateLAF RecoverStateLAF;
struct RecoverStateLAF {
  RecoverBitmap *pUsed;
  i64 nPg;                        /* Size of db in pages */
  sqlite3_stmt *pAllAndParent;
  sqlite3_stmt *pMapInsert;
  sqlite3_stmt *pMaxField;
  sqlite3_stmt *pUsedPages;
  sqlite3_stmt *pFindRoot;
  sqlite3_stmt *pInsert;          /* INSERT INTO lost_and_found ... */
  sqlite3_stmt *pAllPage;
  sqlite3_stmt *pPageData;
  sqlite3_value **apVal;
  int nMaxField;
};

/*
** Main recover handle structure.
*/
struct sqlite3_recover {
  /* Copies of sqlite3_recover_init[_sql]() parameters */
  sqlite3 *dbIn;                  /* Input database */
  char *zDb;                      /* Name of input db ("main" etc.) */
  char *zUri;                     /* URI for output database */
  void *pSqlCtx;                  /* SQL callback context */
  int (*xSql)(void*,const char*); /* Pointer to SQL callback function */

  /* Values configured by sqlite3_recover_config() */
  char *zStateDb;                 /* State database to use (or NULL) */
  char *zLostAndFound;            /* Name of lost-and-found table (or NULL) */
  int bFreelistCorrupt;           /* SQLITE_RECOVER_FREELIST_CORRUPT setting */
  int bRecoverRowid;              /* SQLITE_RECOVER_ROWIDS setting */
  int bSlowIndexes;               /* SQLITE_RECOVER_SLOWINDEXES setting */

  int pgsz;
  int detected_pgsz;
  int nReserve;
  u8 *pPage1Disk;
  u8 *pPage1Cache;

  /* Error code and error message */
  int errCode;                    /* For sqlite3_recover_errcode() */
  char *zErrMsg;                  /* For sqlite3_recover_errmsg() */

  int eState;
  int bCloseTransaction;

  /* Variables used with eState==RECOVER_STATE_WRITING */
  RecoverStateW1 w1;

  /* Variables used with states RECOVER_STATE_LOSTANDFOUND[123] */
  RecoverStateLAF laf;

  /* Fields used within sqlite3_recover_run() */
  sqlite3 *dbOut;                 /* Output database */
  sqlite3_stmt *pGetPage;         /* SELECT against input db sqlite_dbdata */
  RecoverTable *pTblList;         /* List of tables recovered from schema */
};

/*
** The various states in which an sqlite3_recover object may exist:
**
**   RECOVER_STATE_INIT:
**    The object is initially created in this state. sqlite3_recover_step()
**    has yet to be called. This is the only state in which it is permitted
**    to call sqlite3_recover_config().
**
**   RECOVER_STATE_WRITING:
**
**   RECOVER_STATE_LOSTANDFOUND1:
**    State to populate the bitmap of pages used by other tables or the
**    database freelist.
**
**   RECOVER_STATE_LOSTANDFOUND2:
**    Populate the recovery.map table - used to figure out a "root" page
**    for each lost page from in the database from which records are
**    extracted.
**
**   RECOVER_STATE_LOSTANDFOUND3:
**    Populate the lost-and-found table itself.
*/
#define RECOVER_STATE_INIT           0
#define RECOVER_STATE_WRITING        1
#define RECOVER_STATE_LOSTANDFOUND1  2
#define RECOVER_STATE_LOSTANDFOUND2  3
#define RECOVER_STATE_LOSTANDFOUND3  4
#define RECOVER_STATE_SCHEMA2        5
#define RECOVER_STATE_DONE           6


/*
** Global variables used by this extension.
*/
typedef struct RecoverGlobal RecoverGlobal;
struct RecoverGlobal {
  const sqlite3_io_methods *pMethods;
  sqlite3_recover *p;
};
static RecoverGlobal recover_g;

/*
** Use this static SQLite mutex to protect the globals during the
** first call to sqlite3_recover_step().
*/ 
#define RECOVER_MUTEX_ID SQLITE_MUTEX_STATIC_APP2


/* 
** Default value for SQLITE_RECOVER_ROWIDS (sqlite3_recover.bRecoverRowid).
*/
#define RECOVER_ROWID_DEFAULT 1

/*
** Mutex handling:
**
**    recoverEnterMutex()       -   Enter the recovery mutex
**    recoverLeaveMutex()       -   Leave the recovery mutex
**    recoverAssertMutexHeld()  -   Assert that the recovery mutex is held
*/
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE==0
# define recoverEnterMutex()
# define recoverLeaveMutex()
#else
static void recoverEnterMutex(void){
  sqlite3_mutex_enter(sqlite3_mutex_alloc(RECOVER_MUTEX_ID));
}
static void recoverLeaveMutex(void){
  sqlite3_mutex_leave(sqlite3_mutex_alloc(RECOVER_MUTEX_ID));
}
#endif
#if SQLITE_THREADSAFE+0>=1 && defined(SQLITE_DEBUG)
static void recoverAssertMutexHeld(void){
  assert( sqlite3_mutex_held(sqlite3_mutex_alloc(RECOVER_MUTEX_ID)) );
}
#else
# define recoverAssertMutexHeld()
#endif


/*
** Like strlen(). But handles NULL pointer arguments.
*/
static int recoverStrlen(const char *zStr){
  if( zStr==0 ) return 0;
  return (int)(strlen(zStr)&0x7fffffff);
}

/*
** This function is a no-op if the recover handle passed as the first 
** argument already contains an error (if p->errCode!=SQLITE_OK). 
**
** Otherwise, an attempt is made to allocate, zero and return a buffer nByte
** bytes in size. If successful, a pointer to the new buffer is returned. Or,
** if an OOM error occurs, NULL is returned and the handle error code
** (p->errCode) set to SQLITE_NOMEM.
*/
static void *recoverMalloc(sqlite3_recover *p, i64 nByte){
  void *pRet = 0;
  assert( nByte>0 );
  if( p->errCode==SQLITE_OK ){
    pRet = sqlite3_malloc64(nByte);
    if( pRet ){
      memset(pRet, 0, nByte);
    }else{
      p->errCode = SQLITE_NOMEM;
    }
  }
  return pRet;
}

/*
** Set the error code and error message for the recover handle passed as
** the first argument. The error code is set to the value of parameter
** errCode.
**
** Parameter zFmt must be a printf() style formatting string. The handle 
** error message is set to the result of using any trailing arguments for 
** parameter substitutions in the formatting string.
**
** For example:
**
**   recoverError(p, SQLITE_ERROR, "no such table: %s", zTablename);
*/
static int recoverError(
  sqlite3_recover *p, 
  int errCode, 
  const char *zFmt, ...
){
  char *z = 0;
  va_list ap;
  va_start(ap, zFmt);
  if( zFmt ){
    z = sqlite3_vmprintf(zFmt, ap);
  }
  va_end(ap);
  sqlite3_free(p->zErrMsg);
  p->zErrMsg = z;
  p->errCode = errCode;
  return errCode;
}


/*
** This function is a no-op if p->errCode is initially other than SQLITE_OK.
** In this case it returns NULL.
**
** Otherwise, an attempt is made to allocate and return a bitmap object
** large enough to store a bit for all page numbers between 1 and nPg,
** inclusive. The bitmap is initially zeroed.
*/
static RecoverBitmap *recoverBitmapAlloc(sqlite3_recover *p, i64 nPg){
  int nElem = (nPg+1+31) / 32;
  int nByte = SZ_RECOVERBITMAP_32 + nElem*sizeof(u32);
  RecoverBitmap *pRet = (RecoverBitmap*)recoverMalloc(p, nByte);

  if( pRet ){
    pRet->nPg = nPg;
  }
  return pRet;
}

/*
** Free a bitmap object allocated by recoverBitmapAlloc().
*/
static void recoverBitmapFree(RecoverBitmap *pMap){
  sqlite3_free(pMap);
}

/*
** Set the bit associated with page iPg in bitvec pMap.
*/
static void recoverBitmapSet(RecoverBitmap *pMap, i64 iPg){
  if( iPg<=pMap->nPg ){
    int iElem = (iPg / 32);
    int iBit = (iPg % 32);
    pMap->aElem[iElem] |= (((u32)1) << iBit);
  }
}

/*
** Query bitmap object pMap for the state of the bit associated with page
** iPg. Return 1 if it is set, or 0 otherwise.
*/
static int recoverBitmapQuery(RecoverBitmap *pMap, i64 iPg){
  int ret = 1;
  if( iPg<=pMap->nPg && iPg>0 ){
    int iElem = (iPg / 32);
    int iBit = (iPg % 32);
    ret = (pMap->aElem[iElem] & (((u32)1) << iBit)) ? 1 : 0;
  }
  return ret;
}

/*
** Set the recover handle error to the error code and message returned by
** calling sqlite3_errcode() and sqlite3_errmsg(), respectively, on database
** handle db.
*/
static int recoverDbError(sqlite3_recover *p, sqlite3 *db){
  return recoverError(p, sqlite3_errcode(db), "%s", sqlite3_errmsg(db));
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). 
**
** Otherwise, it attempts to prepare the SQL statement in zSql against
** database handle db. If successful, the statement handle is returned.
** Or, if an error occurs, NULL is returned and an error left in the
** recover handle.
*/
static sqlite3_stmt *recoverPrepare(
  sqlite3_recover *p,
  sqlite3 *db, 
  const char *zSql
){
  sqlite3_stmt *pStmt = 0;
  if( p->errCode==SQLITE_OK ){
    if( sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0) ){
      recoverDbError(p, db);
    }
  }
  return pStmt;
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). 
**
** Otherwise, argument zFmt is used as a printf() style format string,
** along with any trailing arguments, to create an SQL statement. This
** SQL statement is prepared against database handle db and, if successful,
** the statment handle returned. Or, if an error occurs - either during
** the printf() formatting or when preparing the resulting SQL - an
** error code and message are left in the recover handle.
*/
static sqlite3_stmt *recoverPreparePrintf(
  sqlite3_recover *p,
  sqlite3 *db, 
  const char *zFmt, ...
){
  sqlite3_stmt *pStmt = 0;
  if( p->errCode==SQLITE_OK ){
    va_list ap;
    char *z;
    va_start(ap, zFmt);
    z = sqlite3_vmprintf(zFmt, ap);
    va_end(ap);
    if( z==0 ){
      p->errCode = SQLITE_NOMEM;
    }else{
      pStmt = recoverPrepare(p, db, z);
      sqlite3_free(z);
    }
  }
  return pStmt;
}

/*
** Reset SQLite statement handle pStmt. If the call to sqlite3_reset() 
** indicates that an error occurred, and there is not already an error
** in the recover handle passed as the first argument, set the error
** code and error message appropriately.
**
** This function returns a copy of the statement handle pointer passed
** as the second argument.
*/
static sqlite3_stmt *recoverReset(sqlite3_recover *p, sqlite3_stmt *pStmt){
  int rc = sqlite3_reset(pStmt);
  if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT && p->errCode==SQLITE_OK ){
    recoverDbError(p, sqlite3_db_handle(pStmt));
  }
  return pStmt;
}

/*
** Finalize SQLite statement handle pStmt. If the call to sqlite3_reset() 
** indicates that an error occurred, and there is not already an error
** in the recover handle passed as the first argument, set the error
** code and error message appropriately.
*/
static void recoverFinalize(sqlite3_recover *p, sqlite3_stmt *pStmt){
  sqlite3 *db = sqlite3_db_handle(pStmt);
  int rc = sqlite3_finalize(pStmt);
  if( rc!=SQLITE_OK && p->errCode==SQLITE_OK ){
    recoverDbError(p, db);
  }
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). A copy of p->errCode is returned in this 
** case.
**
** Otherwise, execute SQL script zSql. If successful, return SQLITE_OK.
** Or, if an error occurs, leave an error code and message in the recover
** handle and return a copy of the error code.
*/
static int recoverExec(sqlite3_recover *p, sqlite3 *db, const char *zSql){
  if( p->errCode==SQLITE_OK ){
    int rc = sqlite3_exec(db, zSql, 0, 0, 0);
    if( rc ){
      recoverDbError(p, db);
    }
  }
  return p->errCode;
}

/*
** Bind the value pVal to parameter iBind of statement pStmt. Leave an
** error in the recover handle passed as the first argument if an error
** (e.g. an OOM) occurs.
*/
static void recoverBindValue(
  sqlite3_recover *p, 
  sqlite3_stmt *pStmt, 
  int iBind, 
  sqlite3_value *pVal
){
  if( p->errCode==SQLITE_OK ){
    int rc = sqlite3_bind_value(pStmt, iBind, pVal);
    if( rc ) recoverError(p, rc, 0);
  }
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). NULL is returned in this case.
**
** Otherwise, an attempt is made to interpret zFmt as a printf() style
** formatting string and the result of using the trailing arguments for
** parameter substitution with it written into a buffer obtained from
** sqlite3_malloc(). If successful, a pointer to the buffer is returned.
** It is the responsibility of the caller to eventually free the buffer
** using sqlite3_free().
**
** Or, if an error occurs, an error code and message is left in the recover
** handle and NULL returned.
*/
static char *recoverMPrintf(sqlite3_recover *p, const char *zFmt, ...){
  va_list ap;
  char *z;
  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
  if( p->errCode==SQLITE_OK ){
    if( z==0 ) p->errCode = SQLITE_NOMEM;
  }else{
    sqlite3_free(z);
    z = 0;
  }
  return z;
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). Zero is returned in this case.
**
** Otherwise, execute "PRAGMA page_count" against the input database. If
** successful, return the integer result. Or, if an error occurs, leave an
** error code and error message in the sqlite3_recover handle and return
** zero.
*/
static i64 recoverPageCount(sqlite3_recover *p){
  i64 nPg = 0;
  if( p->errCode==SQLITE_OK ){
    sqlite3_stmt *pStmt = 0;
    pStmt = recoverPreparePrintf(p, p->dbIn, "PRAGMA %Q.page_count", p->zDb);
    if( pStmt ){
      sqlite3_step(pStmt);
      nPg = sqlite3_column_int64(pStmt, 0);
    }
    recoverFinalize(p, pStmt);
  }
  return nPg;
}

/*
** Implementation of SQL scalar function "read_i32". The first argument to 
** this function must be a blob. The second a non-negative integer. This 
** function reads and returns a 32-bit big-endian integer from byte
** offset (4*<arg2>) of the blob.
**
**     SELECT read_i32(<blob>, <idx>)
*/
static void recoverReadI32(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv
){
  const unsigned char *pBlob;
  int nBlob;
  int iInt;

  assert( argc==2 );
  nBlob = sqlite3_value_bytes(argv[0]);
  pBlob = (const unsigned char*)sqlite3_value_blob(argv[0]);
  iInt = sqlite3_value_int(argv[1]) & 0xFFFF;

  if( (iInt+1)*4<=nBlob ){
    const unsigned char *a = &pBlob[iInt*4];
    i64 iVal = ((i64)a[0]<<24)
             + ((i64)a[1]<<16)
             + ((i64)a[2]<< 8)
             + ((i64)a[3]<< 0);
    sqlite3_result_int64(context, iVal);
  }
}

/*
** Implementation of SQL scalar function "page_is_used". This function
** is used as part of the procedure for locating orphan rows for the
** lost-and-found table, and it depends on those routines having populated
** the sqlite3_recover.laf.pUsed variable.
**
** The only argument to this function is a page-number. It returns true 
** if the page has already been used somehow during data recovery, or false
** otherwise.
**
**     SELECT page_is_used(<pgno>);
*/
static void recoverPageIsUsed(
  sqlite3_context *pCtx,
  int nArg,
  sqlite3_value **apArg
){
  sqlite3_recover *p = (sqlite3_recover*)sqlite3_user_data(pCtx);
  i64 pgno = sqlite3_value_int64(apArg[0]);
  assert( nArg==1 );
  sqlite3_result_int(pCtx, recoverBitmapQuery(p->laf.pUsed, pgno));
}

/*
** The implementation of a user-defined SQL function invoked by the 
** sqlite_dbdata and sqlite_dbptr virtual table modules to access pages
** of the database being recovered.
**
** This function always takes a single integer argument. If the argument
** is zero, then the value returned is the number of pages in the db being
** recovered. If the argument is greater than zero, it is a page number. 
** The value returned in this case is an SQL blob containing the data for 
** the identified page of the db being recovered. e.g.
**
**     SELECT getpage(0);       -- return number of pages in db
**     SELECT getpage(4);       -- return page 4 of db as a blob of data 
*/
static void recoverGetPage(
  sqlite3_context *pCtx,
  int nArg,
  sqlite3_value **apArg
){
  sqlite3_recover *p = (sqlite3_recover*)sqlite3_user_data(pCtx);
  i64 pgno = sqlite3_value_int64(apArg[0]);
  sqlite3_stmt *pStmt = 0;

  assert( nArg==1 );
  if( pgno==0 ){
    i64 nPg = recoverPageCount(p);
    sqlite3_result_int64(pCtx, nPg);
    return;
  }else{
    if( p->pGetPage==0 ){
      pStmt = p->pGetPage = recoverPreparePrintf(
          p, p->dbIn, "SELECT data FROM sqlite_dbpage(%Q) WHERE pgno=?", p->zDb
      );
    }else if( p->errCode==SQLITE_OK ){
      pStmt = p->pGetPage;
    }

    if( pStmt ){
      sqlite3_bind_int64(pStmt, 1, pgno);
      if( SQLITE_ROW==sqlite3_step(pStmt) ){
        const u8 *aPg;
        int nPg;
        assert( p->errCode==SQLITE_OK );
        aPg = sqlite3_column_blob(pStmt, 0);
        nPg = sqlite3_column_bytes(pStmt, 0);
        if( pgno==1 && nPg==p->pgsz && 0==memcmp(p->pPage1Cache, aPg, nPg) ){
          aPg = p->pPage1Disk;
        }
        sqlite3_result_blob(pCtx, aPg, nPg-p->nReserve, SQLITE_TRANSIENT);
      }
      recoverReset(p, pStmt);
    }
  }

  if( p->errCode ){
    if( p->zErrMsg ) sqlite3_result_error(pCtx, p->zErrMsg, -1);
    sqlite3_result_error_code(pCtx, p->errCode);
  }
}

/*
** Find a string that is not found anywhere in z[].  Return a pointer
** to that string.
**
** Try to use zA and zB first.  If both of those are already found in z[]
** then make up some string and store it in the buffer zBuf.
*/
static const char *recoverUnusedString(
  const char *z,                    /* Result must not appear anywhere in z */
  const char *zA, const char *zB,   /* Try these first */
  char *zBuf                        /* Space to store a generated string */
){
  unsigned i = 0;
  if( strstr(z, zA)==0 ) return zA;
  if( strstr(z, zB)==0 ) return zB;
  do{
    sqlite3_snprintf(20,zBuf,"(%s%u)", zA, i++);
  }while( strstr(z,zBuf)!=0 );
  return zBuf;
}

/*
** Implementation of scalar SQL function "escape_crlf".  The argument passed to
** this function is the output of built-in function quote(). If the first
** character of the input is "'", indicating that the value passed to quote()
** was a text value, then this function searches the input for "\n" and "\r"
** characters and adds a wrapper similar to the following:
**
**   replace(replace(<input>, '\n', char(10), '\r', char(13));
**
** Or, if the first character of the input is not "'", then a copy of the input
** is returned.
*/
static void recoverEscapeCrlf(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv
){
  const char *zText = (const char*)sqlite3_value_text(argv[0]);
  (void)argc;
  if( zText && zText[0]=='\'' ){
    int nText = sqlite3_value_bytes(argv[0]);
    int i;
    char zBuf1[20];
    char zBuf2[20];
    const char *zNL = 0;
    const char *zCR = 0;
    int nCR = 0;
    int nNL = 0;

    for(i=0; zText[i]; i++){
      if( zNL==0 && zText[i]=='\n' ){
        zNL = recoverUnusedString(zText, "\\n", "\\012", zBuf1);
        nNL = (int)strlen(zNL);
      }
      if( zCR==0 && zText[i]=='\r' ){
        zCR = recoverUnusedString(zText, "\\r", "\\015", zBuf2);
        nCR = (int)strlen(zCR);
      }
    }

    if( zNL || zCR ){
      int iOut = 0;
      i64 nMax = (nNL > nCR) ? nNL : nCR;
      i64 nAlloc = nMax * nText + (nMax+64)*2;
      char *zOut = (char*)sqlite3_malloc64(nAlloc);
      if( zOut==0 ){
        sqlite3_result_error_nomem(context);
        return;
      }

      if( zNL && zCR ){
        memcpy(&zOut[iOut], "replace(replace(", 16);
        iOut += 16;
      }else{
        memcpy(&zOut[iOut], "replace(", 8);
        iOut += 8;
      }
      for(i=0; zText[i]; i++){
        if( zText[i]=='\n' ){
          memcpy(&zOut[iOut], zNL, nNL);
          iOut += nNL;
        }else if( zText[i]=='\r' ){
          memcpy(&zOut[iOut], zCR, nCR);
          iOut += nCR;
        }else{
          zOut[iOut] = zText[i];
          iOut++;
        }
      }

      if( zNL ){
        memcpy(&zOut[iOut], ",'", 2); iOut += 2;
        memcpy(&zOut[iOut], zNL, nNL); iOut += nNL;
        memcpy(&zOut[iOut], "', char(10))", 12); iOut += 12;
      }
      if( zCR ){
        memcpy(&zOut[iOut], ",'", 2); iOut += 2;
        memcpy(&zOut[iOut], zCR, nCR); iOut += nCR;
        memcpy(&zOut[iOut], "', char(13))", 12); iOut += 12;
      }

      sqlite3_result_text(context, zOut, iOut, SQLITE_TRANSIENT);
      sqlite3_free(zOut);
      return;
    }
  }

  sqlite3_result_value(context, argv[0]);
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). A copy of the error code is returned in
** this case. 
**
** Otherwise, attempt to populate temporary table "recovery.schema" with the
** parts of the database schema that can be extracted from the input database.
**
** If no error occurs, SQLITE_OK is returned. Otherwise, an error code
** and error message are left in the recover handle and a copy of the
** error code returned. It is not considered an error if part of all of
** the database schema cannot be recovered due to corruption.
*/
static int recoverCacheSchema(sqlite3_recover *p){
  return recoverExec(p, p->dbOut,
    "WITH RECURSIVE pages(p) AS ("
    "  SELECT 1"
    "    UNION"
    "  SELECT child FROM sqlite_dbptr('getpage()'), pages WHERE pgno=p"
    ")"
    "INSERT INTO recovery.schema SELECT"
    "  max(CASE WHEN field=0 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=1 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=2 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=3 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=4 THEN value ELSE NULL END)"
    "FROM sqlite_dbdata('getpage()') WHERE pgno IN ("
    "  SELECT p FROM pages"
    ") GROUP BY pgno, cell"
  );
}

/*
** If this recover handle is not in SQL callback mode (i.e. was not created 
** using sqlite3_recover_init_sql()) of if an error has already occurred, 
** this function is a no-op. Otherwise, issue a callback with SQL statement
** zSql as the parameter. 
**
** If the callback returns non-zero, set the recover handle error code to
** the value returned (so that the caller will abandon processing).
*/
static void recoverSqlCallback(sqlite3_recover *p, const char *zSql){
  if( p->errCode==SQLITE_OK && p->xSql ){
    int res = p->xSql(p->pSqlCtx, zSql);
    if( res ){
      recoverError(p, SQLITE_ERROR, "callback returned an error - %d", res);
    }
  }
}

/*
** Transfer the following settings from the input database to the output
** database:
**
**   + page-size,
**   + auto-vacuum settings,
**   + database encoding,
**   + user-version (PRAGMA user_version), and
**   + application-id (PRAGMA application_id), and
*/
static void recoverTransferSettings(sqlite3_recover *p){
  const char *aPragma[] = {
    "encoding",
    "page_size",
    "auto_vacuum",
    "user_version",
    "application_id"
  };
  int ii;

  /* Truncate the output database to 0 pages in size. This is done by 
  ** opening a new, empty, temp db, then using the backup API to clobber 
  ** any existing output db with a copy of it. */
  if( p->errCode==SQLITE_OK ){
    sqlite3 *db2 = 0;
    int rc = sqlite3_open("", &db2);
    if( rc!=SQLITE_OK ){
      recoverDbError(p, db2);
      return;
    }

    for(ii=0; ii<(int)(sizeof(aPragma)/sizeof(aPragma[0])); ii++){
      const char *zPrag = aPragma[ii];
      sqlite3_stmt *p1 = 0;
      p1 = recoverPreparePrintf(p, p->dbIn, "PRAGMA %Q.%s", p->zDb, zPrag);
      if( p->errCode==SQLITE_OK && sqlite3_step(p1)==SQLITE_ROW ){
        const char *zArg = (const char*)sqlite3_column_text(p1, 0);
        char *z2 = recoverMPrintf(p, "PRAGMA %s = %Q", zPrag, zArg);
        recoverSqlCallback(p, z2);
        recoverExec(p, db2, z2);
        sqlite3_free(z2);
        if( zArg==0 ){
          recoverError(p, SQLITE_NOMEM, 0);
        }
      }
      recoverFinalize(p, p1);
    }
    recoverExec(p, db2, "CREATE TABLE t1(a); DROP TABLE t1;");

    if( p->errCode==SQLITE_OK ){
      sqlite3 *db = p->dbOut;
      sqlite3_backup *pBackup = sqlite3_backup_init(db, "main", db2, "main");
      if( pBackup ){
        sqlite3_backup_step(pBackup, -1);
        p->errCode = sqlite3_backup_finish(pBackup);
      }else{
        recoverDbError(p, db);
      }
    }

    sqlite3_close(db2);
  }
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). A copy of the error code is returned in
** this case. 
**
** Otherwise, an attempt is made to open the output database, attach
** and create the schema of the temporary database used to store
** intermediate data, and to register all required user functions and
** virtual table modules with the output handle.
**
** If no error occurs, SQLITE_OK is returned. Otherwise, an error code
** and error message are left in the recover handle and a copy of the
** error code returned.
*/
static int recoverOpenOutput(sqlite3_recover *p){
  struct Func {
    const char *zName;
    int nArg;
    void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
  } aFunc[] = {
    { "getpage", 1, recoverGetPage },
    { "page_is_used", 1, recoverPageIsUsed },
    { "read_i32", 2, recoverReadI32 },
    { "escape_crlf", 1, recoverEscapeCrlf },
  };

  const int flags = SQLITE_OPEN_URI|SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE;
  sqlite3 *db = 0;                /* New database handle */
  int ii;                         /* For iterating through aFunc[] */

  assert( p->dbOut==0 );

  if( sqlite3_open_v2(p->zUri, &db, flags, 0) ){
    recoverDbError(p, db);
  }

  /* Register the sqlite_dbdata and sqlite_dbptr virtual table modules.
  ** These two are registered with the output database handle - this
  ** module depends on the input handle supporting the sqlite_dbpage
  ** virtual table only.  */
  if( p->errCode==SQLITE_OK ){
    p->errCode = sqlite3_dbdata_init(db, 0, 0);
  }

  /* Register the custom user-functions with the output handle. */
  for(ii=0;
      p->errCode==SQLITE_OK && ii<(int)(sizeof(aFunc)/sizeof(aFunc[0]));
      ii++){
    p->errCode = sqlite3_create_function(db, aFunc[ii].zName, 
        aFunc[ii].nArg, SQLITE_UTF8, (void*)p, aFunc[ii].xFunc, 0, 0
    );
  }

  p->dbOut = db;
  return p->errCode;
}

/*
** Attach the auxiliary database 'recovery' to the output database handle.
** This temporary database is used during the recovery process and then 
** discarded.
*/
static void recoverOpenRecovery(sqlite3_recover *p){
  char *zSql = recoverMPrintf(p, "ATTACH %Q AS recovery;", p->zStateDb);
  recoverExec(p, p->dbOut, zSql);
  recoverExec(p, p->dbOut,
      "PRAGMA writable_schema = 1;"
      "CREATE TABLE recovery.map(pgno INTEGER PRIMARY KEY, parent INT);" 
      "CREATE TABLE recovery.schema(type, name, tbl_name, rootpage, sql);"
  );
  sqlite3_free(zSql);
}


/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK).
**
** Otherwise, argument zName must be the name of a table that has just been
** created in the output database. This function queries the output db
** for the schema of said table, and creates a RecoverTable object to
** store the schema in memory. The new RecoverTable object is linked into
** the list at sqlite3_recover.pTblList.
**
** Parameter iRoot must be the root page of table zName in the INPUT 
** database.
*/
static void recoverAddTable(
  sqlite3_recover *p, 
  const char *zName,              /* Name of table created in output db */
  i64 iRoot                       /* Root page of same table in INPUT db */
){
  sqlite3_stmt *pStmt = recoverPreparePrintf(p, p->dbOut, 
      "PRAGMA table_xinfo(%Q)", zName
  );

  if( pStmt ){
    int iPk = -1;
    int iBind = 1;
    RecoverTable *pNew = 0;
    int nCol = 0;
    int nName = recoverStrlen(zName);
    int nByte = 0;
    while( sqlite3_step(pStmt)==SQLITE_ROW ){
      nCol++;
      nByte += (sqlite3_column_bytes(pStmt, 1)+1);
    }
    nByte += sizeof(RecoverTable) + nCol*sizeof(RecoverColumn) + nName+1;
    recoverReset(p, pStmt);

    pNew = recoverMalloc(p, nByte);
    if( pNew ){
      int i = 0;
      int iField = 0;
      char *csr = 0;
      pNew->aCol = (RecoverColumn*)&pNew[1];
      pNew->zTab = csr = (char*)&pNew->aCol[nCol];
      pNew->nCol = nCol;
      pNew->iRoot = iRoot;
      memcpy(csr, zName, nName);
      csr += nName+1;

      for(i=0; sqlite3_step(pStmt)==SQLITE_ROW; i++){
        int iPKF = sqlite3_column_int(pStmt, 5);
        int n = sqlite3_column_bytes(pStmt, 1);
        const char *z = (const char*)sqlite3_column_text(pStmt, 1);
        const char *zType = (const char*)sqlite3_column_text(pStmt, 2);
        int eHidden = sqlite3_column_int(pStmt, 6);

        if( iPk==-1 && iPKF==1 && !sqlite3_stricmp("integer", zType) ) iPk = i;
        if( iPKF>1 ) iPk = -2;
        pNew->aCol[i].zCol = csr;
        pNew->aCol[i].eHidden = eHidden;
        if( eHidden==RECOVER_EHIDDEN_VIRTUAL ){
          pNew->aCol[i].iField = -1;
        }else{
          pNew->aCol[i].iField = iField++;
        }
        if( eHidden!=RECOVER_EHIDDEN_VIRTUAL
         && eHidden!=RECOVER_EHIDDEN_STORED
        ){
          pNew->aCol[i].iBind = iBind++;
        }
        memcpy(csr, z, n);
        csr += (n+1);
      }

      pNew->pNext = p->pTblList;
      p->pTblList = pNew;
      pNew->bIntkey = 1;
    }

    recoverFinalize(p, pStmt);

    pStmt = recoverPreparePrintf(p, p->dbOut, "PRAGMA index_xinfo(%Q)", zName);
    while( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
      int iField = sqlite3_column_int(pStmt, 0);
      int iCol = sqlite3_column_int(pStmt, 1);

      assert( iCol<pNew->nCol );
      pNew->aCol[iCol].iField = iField;

      pNew->bIntkey = 0;
      iPk = -2;
    }
    recoverFinalize(p, pStmt);

    if( p->errCode==SQLITE_OK ){
      if( iPk>=0 ){
        pNew->aCol[iPk].bIPK = 1;
      }else if( pNew->bIntkey ){
        pNew->iRowidBind = iBind++;
      }
    }
  }
}

/*
** This function is called after recoverCacheSchema() has cached those parts
** of the input database schema that could be recovered in temporary table
** "recovery.schema". This function creates in the output database copies
** of all parts of that schema that must be created before the tables can
** be populated. Specifically, this means:
**
**     * all tables that are not VIRTUAL, and
**     * UNIQUE indexes.
**
** If the recovery handle uses SQL callbacks, then callbacks containing
** the associated "CREATE TABLE" and "CREATE INDEX" statements are made.
**
** Additionally, records are added to the sqlite_schema table of the
** output database for any VIRTUAL tables. The CREATE VIRTUAL TABLE
** records are written directly to sqlite_schema, not actually executed.
** If the handle is in SQL callback mode, then callbacks are invoked 
** with equivalent SQL statements.
*/
static int recoverWriteSchema1(sqlite3_recover *p){
  sqlite3_stmt *pSelect = 0;
  sqlite3_stmt *pTblname = 0;

  pSelect = recoverPrepare(p, p->dbOut,
      "WITH dbschema(rootpage, name, sql, tbl, isVirtual, isIndex) AS ("
      "  SELECT rootpage, name, sql, "
      "    type='table', "
      "    sql LIKE 'create virtual%',"
      "    (type='index' AND (sql LIKE '%unique%' OR ?1))"
      "  FROM recovery.schema"
      ")"
      "SELECT rootpage, tbl, isVirtual, name, sql"
      " FROM dbschema "
      "  WHERE tbl OR isIndex"
      "  ORDER BY tbl DESC, name=='sqlite_sequence' DESC"
  );

  pTblname = recoverPrepare(p, p->dbOut,
      "SELECT name FROM sqlite_schema "
      "WHERE type='table' ORDER BY rowid DESC LIMIT 1"
  );

  if( pSelect ){
    sqlite3_bind_int(pSelect, 1, p->bSlowIndexes);
    while( sqlite3_step(pSelect)==SQLITE_ROW ){
      i64 iRoot = sqlite3_column_int64(pSelect, 0);
      int bTable = sqlite3_column_int(pSelect, 1);
      int bVirtual = sqlite3_column_int(pSelect, 2);
      const char *zName = (const char*)sqlite3_column_text(pSelect, 3);
      const char *zSql = (const char*)sqlite3_column_text(pSelect, 4);
      char *zFree = 0;
      int rc = SQLITE_OK;

      if( bVirtual ){
        zSql = (const char*)(zFree = recoverMPrintf(p,
            "INSERT INTO sqlite_schema VALUES('table', %Q, %Q, 0, %Q)",
            zName, zName, zSql
        ));
      }
      rc = sqlite3_exec(p->dbOut, zSql, 0, 0, 0);
      if( rc==SQLITE_OK ){
        recoverSqlCallback(p, zSql);
        if( bTable && !bVirtual ){
          if( SQLITE_ROW==sqlite3_step(pTblname) ){
            const char *zTbl = (const char*)sqlite3_column_text(pTblname, 0);
            if( zTbl ) recoverAddTable(p, zTbl, iRoot);
          }
          recoverReset(p, pTblname);
        }
      }else if( rc!=SQLITE_ERROR ){
        recoverDbError(p, p->dbOut);
      }
      sqlite3_free(zFree);
    }
  }
  recoverFinalize(p, pSelect);
  recoverFinalize(p, pTblname);

  return p->errCode;
}

/*
** This function is called after the output database has been populated. It
** adds all recovered schema elements that were not created in the output
** database by recoverWriteSchema1() - everything except for tables and
** UNIQUE indexes. Specifically:
**
**     * views,
**     * triggers,
**     * non-UNIQUE indexes.
**
** If the recover handle is in SQL callback mode, then equivalent callbacks
** are issued to create the schema elements.
*/
static int recoverWriteSchema2(sqlite3_recover *p){
  sqlite3_stmt *pSelect = 0;

  pSelect = recoverPrepare(p, p->dbOut,
      p->bSlowIndexes ?
      "SELECT rootpage, sql FROM recovery.schema "
      "  WHERE type!='table' AND type!='index'"
      :
      "SELECT rootpage, sql FROM recovery.schema "
      "  WHERE type!='table' AND (type!='index' OR sql NOT LIKE '%unique%')"
  );

  if( pSelect ){
    while( sqlite3_step(pSelect)==SQLITE_ROW ){
      const char *zSql = (const char*)sqlite3_column_text(pSelect, 1);
      int rc = sqlite3_exec(p->dbOut, zSql, 0, 0, 0);
      if( rc==SQLITE_OK ){
        recoverSqlCallback(p, zSql);
      }else if( rc!=SQLITE_ERROR ){
        recoverDbError(p, p->dbOut);
      }
    }
  }
  recoverFinalize(p, pSelect);

  return p->errCode;
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). In this case it returns NULL.
**
** Otherwise, if the recover handle is configured to create an output
** database (was created by sqlite3_recover_init()), then this function
** prepares and returns an SQL statement to INSERT a new record into table
** pTab, assuming the first nField fields of a record extracted from disk
** are valid.
**
** For example, if table pTab is:
**
**     CREATE TABLE name(a, b GENERATED ALWAYS AS (a+1) STORED, c, d, e);
**
** And nField is 4, then the SQL statement prepared and returned is:
**
**     INSERT INTO (a, c, d) VALUES (?1, ?2, ?3);
**
** In this case even though 4 values were extracted from the input db,
** only 3 are written to the output, as the generated STORED column 
** cannot be written.
**
** If the recover handle is in SQL callback mode, then the SQL statement
** prepared is such that evaluating it returns a single row containing
** a single text value - itself an SQL statement similar to the above,
** except with SQL literals in place of the variables. For example:
**
**     SELECT 'INSERT INTO (a, c, d) VALUES (' 
**          || quote(?1) || ', '
**          || quote(?2) || ', '
**          || quote(?3) || ')';
**
** In either case, it is the responsibility of the caller to eventually
** free the statement handle using sqlite3_finalize().
*/
static sqlite3_stmt *recoverInsertStmt(
  sqlite3_recover *p, 
  RecoverTable *pTab,
  int nField
){
  sqlite3_stmt *pRet = 0;
  const char *zSep = "";
  const char *zSqlSep = "";
  char *zSql = 0;
  char *zFinal = 0;
  char *zBind = 0;
  int ii;
  int bSql = p->xSql ? 1 : 0;

  if( nField<=0 ) return 0;

  assert( nField<=pTab->nCol );

  zSql = recoverMPrintf(p, "INSERT OR IGNORE INTO %Q(", pTab->zTab);

  if( pTab->iRowidBind ){
    assert( pTab->bIntkey );
    zSql = recoverMPrintf(p, "%z_rowid_", zSql);
    if( bSql ){
      zBind = recoverMPrintf(p, "%zquote(?%d)", zBind, pTab->iRowidBind);
    }else{
      zBind = recoverMPrintf(p, "%z?%d", zBind, pTab->iRowidBind);
    }
    zSqlSep = "||', '||";
    zSep = ", ";
  }

  for(ii=0; ii<nField; ii++){
    int eHidden = pTab->aCol[ii].eHidden;
    if( eHidden!=RECOVER_EHIDDEN_VIRTUAL
     && eHidden!=RECOVER_EHIDDEN_STORED
    ){
      assert( pTab->aCol[ii].iField>=0 && pTab->aCol[ii].iBind>=1 );
      zSql = recoverMPrintf(p, "%z%s%Q", zSql, zSep, pTab->aCol[ii].zCol);

      if( bSql ){
        zBind = recoverMPrintf(p, 
            "%z%sescape_crlf(quote(?%d))", zBind, zSqlSep, pTab->aCol[ii].iBind
        );
        zSqlSep = "||', '||";
      }else{
        zBind = recoverMPrintf(p, "%z%s?%d", zBind, zSep, pTab->aCol[ii].iBind);
      }
      zSep = ", ";
    }
  }

  if( bSql ){
    zFinal = recoverMPrintf(p, "SELECT %Q || ') VALUES (' || %s || ')'", 
        zSql, zBind
    );
  }else{
    zFinal = recoverMPrintf(p, "%s) VALUES (%s)", zSql, zBind);
  }

  pRet = recoverPrepare(p, p->dbOut, zFinal);
  sqlite3_free(zSql);
  sqlite3_free(zBind);
  sqlite3_free(zFinal);
  
  return pRet;
}


/*
** Search the list of RecoverTable objects at p->pTblList for one that
** has root page iRoot in the input database. If such an object is found,
** return a pointer to it. Otherwise, return NULL.
*/
static RecoverTable *recoverFindTable(sqlite3_recover *p, u32 iRoot){
  RecoverTable *pRet = 0;
  for(pRet=p->pTblList; pRet && pRet->iRoot!=iRoot; pRet=pRet->pNext);
  return pRet;
}

/*
** This function attempts to create a lost and found table within the 
** output db. If successful, it returns a pointer to a buffer containing
** the name of the new table. It is the responsibility of the caller to
** eventually free this buffer using sqlite3_free().
**
** If an error occurs, NULL is returned and an error code and error 
** message left in the recover handle.
*/
static char *recoverLostAndFoundCreate(
  sqlite3_recover *p,             /* Recover object */
  int nField                      /* Number of column fields in new table */
){
  char *zTbl = 0;
  sqlite3_stmt *pProbe = 0;
  int ii = 0;

  pProbe = recoverPrepare(p, p->dbOut,
    "SELECT 1 FROM sqlite_schema WHERE name=?"
  );
  for(ii=-1; zTbl==0 && p->errCode==SQLITE_OK && ii<1000; ii++){
    int bFail = 0;
    if( ii<0 ){
      zTbl = recoverMPrintf(p, "%s", p->zLostAndFound);
    }else{
      zTbl = recoverMPrintf(p, "%s_%d", p->zLostAndFound, ii);
    }

    if( p->errCode==SQLITE_OK ){
      sqlite3_bind_text(pProbe, 1, zTbl, -1, SQLITE_STATIC);
      if( SQLITE_ROW==sqlite3_step(pProbe) ){
        bFail = 1;
      }
      recoverReset(p, pProbe);
    }

    if( bFail ){
      sqlite3_clear_bindings(pProbe);
      sqlite3_free(zTbl);
      zTbl = 0;
    }
  }
  recoverFinalize(p, pProbe);

  if( zTbl ){
    const char *zSep = 0;
    char *zField = 0;
    char *zSql = 0;

    zSep = "rootpgno INTEGER, pgno INTEGER, nfield INTEGER, id INTEGER, ";
    for(ii=0; p->errCode==SQLITE_OK && ii<nField; ii++){
      zField = recoverMPrintf(p, "%z%sc%d", zField, zSep, ii);
      zSep = ", ";
    }

    zSql = recoverMPrintf(p, "CREATE TABLE %s(%s)", zTbl, zField);
    sqlite3_free(zField);

    recoverExec(p, p->dbOut, zSql);
    recoverSqlCallback(p, zSql);
    sqlite3_free(zSql);
  }else if( p->errCode==SQLITE_OK ){
    recoverError(
        p, SQLITE_ERROR, "failed to create %s output table", p->zLostAndFound
    );
  }

  return zTbl;
}

/*
** Synthesize and prepare an INSERT statement to write to the lost_and_found
** table in the output database. The name of the table is zTab, and it has
** nField c* fields.
*/
static sqlite3_stmt *recoverLostAndFoundInsert(
  sqlite3_recover *p,
  const char *zTab,
  int nField
){
  int nTotal = nField + 4;
  int ii;
  char *zBind = 0;
  sqlite3_stmt *pRet = 0;

  if( p->xSql==0 ){
    for(ii=0; ii<nTotal; ii++){
      zBind = recoverMPrintf(p, "%z%s?", zBind, zBind?", ":"", ii);
    }
    pRet = recoverPreparePrintf(
        p, p->dbOut, "INSERT INTO %s VALUES(%s)", zTab, zBind
    );
  }else{
    const char *zSep = "";
    for(ii=0; ii<nTotal; ii++){
      zBind = recoverMPrintf(p, "%z%squote(?)", zBind, zSep);
      zSep = "|| ', ' ||";
    }
    pRet = recoverPreparePrintf(
        p, p->dbOut, "SELECT 'INSERT INTO %s VALUES(' || %s || ')'", zTab, zBind
    );
  }

  sqlite3_free(zBind);
  return pRet;
}

/*
** Input database page iPg contains data that will be written to the
** lost-and-found table of the output database. This function attempts
** to identify the root page of the tree that page iPg belonged to.
** If successful, it sets output variable (*piRoot) to the page number
** of the root page and returns SQLITE_OK. Otherwise, if an error occurs,
** an SQLite error code is returned and the final value of *piRoot 
** undefined.
*/
static int recoverLostAndFoundFindRoot(
  sqlite3_recover *p, 
  i64 iPg,
  i64 *piRoot
){
  RecoverStateLAF *pLaf = &p->laf;

  if( pLaf->pFindRoot==0 ){
    pLaf->pFindRoot = recoverPrepare(p, p->dbOut,
        "WITH RECURSIVE p(pgno) AS ("
        "  SELECT ?"
        "    UNION"
        "  SELECT parent FROM recovery.map AS m, p WHERE m.pgno=p.pgno"
        ") "
        "SELECT p.pgno FROM p, recovery.map m WHERE m.pgno=p.pgno "
        "    AND m.parent IS NULL"
    );
  }
  if( p->errCode==SQLITE_OK ){
    sqlite3_bind_int64(pLaf->pFindRoot, 1, iPg);
    if( sqlite3_step(pLaf->pFindRoot)==SQLITE_ROW ){
      *piRoot = sqlite3_column_int64(pLaf->pFindRoot, 0);
    }else{
      *piRoot = iPg;
    }
    recoverReset(p, pLaf->pFindRoot);
  }
  return p->errCode;
}

/*
** Recover data from page iPage of the input database and write it to
** the lost-and-found table in the output database.
*/
static void recoverLostAndFoundOnePage(sqlite3_recover *p, i64 iPage){
  RecoverStateLAF *pLaf = &p->laf;
  sqlite3_value **apVal = pLaf->apVal;
  sqlite3_stmt *pPageData = pLaf->pPageData;
  sqlite3_stmt *pInsert = pLaf->pInsert;

  int nVal = -1;
  int iPrevCell = 0;
  i64 iRoot = 0;
  int bHaveRowid = 0;
  i64 iRowid = 0;
  int ii = 0;

  if( recoverLostAndFoundFindRoot(p, iPage, &iRoot) ) return;
  sqlite3_bind_int64(pPageData, 1, iPage);
  while( p->errCode==SQLITE_OK && SQLITE_ROW==sqlite3_step(pPageData) ){
    int iCell = sqlite3_column_int64(pPageData, 0);
    int iField = sqlite3_column_int64(pPageData, 1);

    if( iPrevCell!=iCell && nVal>=0 ){
      /* Insert the new row */
      sqlite3_bind_int64(pInsert, 1, iRoot);      /* rootpgno */
      sqlite3_bind_int64(pInsert, 2, iPage);      /* pgno */
      sqlite3_bind_int(pInsert, 3, nVal);         /* nfield */
      if( bHaveRowid ){
        sqlite3_bind_int64(pInsert, 4, iRowid);   /* id */
      }
      for(ii=0; ii<nVal; ii++){
        recoverBindValue(p, pInsert, 5+ii, apVal[ii]);
      }
      if( sqlite3_step(pInsert)==SQLITE_ROW ){
        recoverSqlCallback(p, (const char*)sqlite3_column_text(pInsert, 0));
      }
      recoverReset(p, pInsert);

      /* Discard the accumulated row data */
      for(ii=0; ii<nVal; ii++){
        sqlite3_value_free(apVal[ii]);
        apVal[ii] = 0;
      }
      sqlite3_clear_bindings(pInsert);
      bHaveRowid = 0;
      nVal = -1;
    }

    if( iCell<0 ) break;

    if( iField<0 ){
      assert( nVal==-1 );
      iRowid = sqlite3_column_int64(pPageData, 2);
      bHaveRowid = 1;
      nVal = 0;
    }else if( iField<pLaf->nMaxField ){
      sqlite3_value *pVal = sqlite3_column_value(pPageData, 2);
      apVal[iField] = sqlite3_value_dup(pVal);
      assert( iField==nVal || (nVal==-1 && iField==0) );
      nVal = iField+1;
      if( apVal[iField]==0 ){
        recoverError(p, SQLITE_NOMEM, 0);
      }
    }

    iPrevCell = iCell;
  }
  recoverReset(p, pPageData);

  for(ii=0; ii<nVal; ii++){
    sqlite3_value_free(apVal[ii]);
    apVal[ii] = 0;
  }
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_LOSTANDFOUND3 state - during which the lost-and-found 
** table of the output database is populated with recovered data that can 
** not be assigned to any recovered schema object.
*/ 
static int recoverLostAndFound3Step(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  if( p->errCode==SQLITE_OK ){
    if( pLaf->pInsert==0 ){
      return SQLITE_DONE;
    }else{
      if( p->errCode==SQLITE_OK ){
        int res = sqlite3_step(pLaf->pAllPage);
        if( res==SQLITE_ROW ){
          i64 iPage = sqlite3_column_int64(pLaf->pAllPage, 0);
          if( recoverBitmapQuery(pLaf->pUsed, iPage)==0 ){
            recoverLostAndFoundOnePage(p, iPage);
          }
        }else{
          recoverReset(p, pLaf->pAllPage);
          return SQLITE_DONE;
        }
      }
    }
  }
  return SQLITE_OK;
}

/*
** Initialize resources required in RECOVER_STATE_LOSTANDFOUND3 
** state - during which the lost-and-found table of the output database 
** is populated with recovered data that can not be assigned to any 
** recovered schema object.
*/ 
static void recoverLostAndFound3Init(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;

  if( pLaf->nMaxField>0 ){
    char *zTab = 0;               /* Name of lost_and_found table */

    zTab = recoverLostAndFoundCreate(p, pLaf->nMaxField);
    pLaf->pInsert = recoverLostAndFoundInsert(p, zTab, pLaf->nMaxField);
    sqlite3_free(zTab);

    pLaf->pAllPage = recoverPreparePrintf(p, p->dbOut,
        "WITH RECURSIVE seq(ii) AS ("
        "  SELECT 1 UNION ALL SELECT ii+1 FROM seq WHERE ii<%lld"
        ")"
        "SELECT ii FROM seq" , p->laf.nPg
    );
    pLaf->pPageData = recoverPrepare(p, p->dbOut,
        "SELECT cell, field, value "
        "FROM sqlite_dbdata('getpage()') d WHERE d.pgno=? "
        "UNION ALL "
        "SELECT -1, -1, -1"
    );

    pLaf->apVal = (sqlite3_value**)recoverMalloc(p, 
        pLaf->nMaxField*sizeof(sqlite3_value*)
    );
  }
}

/*
** Initialize resources required in RECOVER_STATE_WRITING state - during which
** tables recovered from the schema of the input database are populated with
** recovered data.
*/ 
static int recoverWriteDataInit(sqlite3_recover *p){
  RecoverStateW1 *p1 = &p->w1;
  RecoverTable *pTbl = 0;
  int nByte = 0;

  /* Figure out the maximum number of columns for any table in the schema */
  assert( p1->nMax==0 );
  for(pTbl=p->pTblList; pTbl; pTbl=pTbl->pNext){
    if( pTbl->nCol>p1->nMax ) p1->nMax = pTbl->nCol;
  }

  /* Allocate an array of (sqlite3_value*) in which to accumulate the values
  ** that will be written to the output database in a single row. */
  nByte = sizeof(sqlite3_value*) * (p1->nMax+1);
  p1->apVal = (sqlite3_value**)recoverMalloc(p, nByte);
  if( p1->apVal==0 ) return p->errCode;

  /* Prepare the SELECT to loop through schema tables (pTbls) and the SELECT
  ** to loop through cells that appear to belong to a single table (pSel). */
  p1->pTbls = recoverPrepare(p, p->dbOut,
      "SELECT rootpage FROM recovery.schema "
      "  WHERE type='table' AND (sql NOT LIKE 'create virtual%')"
      "  ORDER BY (tbl_name='sqlite_sequence') ASC"
  );
  p1->pSel = recoverPrepare(p, p->dbOut, 
      "WITH RECURSIVE pages(page) AS ("
      "  SELECT ?1"
      "    UNION"
      "  SELECT child FROM sqlite_dbptr('getpage()'), pages "
      "    WHERE pgno=page"
      ") "
      "SELECT page, cell, field, value "
      "FROM sqlite_dbdata('getpage()') d, pages p WHERE p.page=d.pgno "
      "UNION ALL "
      "SELECT 0, 0, 0, 0"
  );

  return p->errCode;
}

/*
** Clean up resources allocated by recoverWriteDataInit() (stuff in 
** sqlite3_recover.w1).
*/
static void recoverWriteDataCleanup(sqlite3_recover *p){
  RecoverStateW1 *p1 = &p->w1;
  int ii;
  for(ii=0; ii<p1->nVal; ii++){
    sqlite3_value_free(p1->apVal[ii]);
  }
  sqlite3_free(p1->apVal);
  recoverFinalize(p, p1->pInsert);
  recoverFinalize(p, p1->pTbls);
  recoverFinalize(p, p1->pSel);
  memset(p1, 0, sizeof(*p1));
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_WRITING state - during which tables recovered from the
** schema of the input database are populated with recovered data.
*/ 
static int recoverWriteDataStep(sqlite3_recover *p){
  RecoverStateW1 *p1 = &p->w1;
  sqlite3_stmt *pSel = p1->pSel;
  sqlite3_value **apVal = p1->apVal;

  if( p->errCode==SQLITE_OK && p1->pTab==0 ){
    if( sqlite3_step(p1->pTbls)==SQLITE_ROW ){
      i64 iRoot = sqlite3_column_int64(p1->pTbls, 0);
      p1->pTab = recoverFindTable(p, iRoot);

      recoverFinalize(p, p1->pInsert);
      p1->pInsert = 0;

      /* If this table is unknown, return early. The caller will invoke this
      ** function again and it will move on to the next table.  */
      if( p1->pTab==0 ) return p->errCode;

      /* If this is the sqlite_sequence table, delete any rows added by
      ** earlier INSERT statements on tables with AUTOINCREMENT primary
      ** keys before recovering its contents. The p1->pTbls SELECT statement
      ** is rigged to deliver "sqlite_sequence" last of all, so we don't
      ** worry about it being modified after it is recovered. */
      if( sqlite3_stricmp("sqlite_sequence", p1->pTab->zTab)==0 ){
        recoverExec(p, p->dbOut, "DELETE FROM sqlite_sequence");
        recoverSqlCallback(p, "DELETE FROM sqlite_sequence");
      }

      /* Bind the root page of this table within the original database to 
      ** SELECT statement p1->pSel. The SELECT statement will then iterate
      ** through cells that look like they belong to table pTab.  */
      sqlite3_bind_int64(pSel, 1, iRoot);

      p1->nVal = 0;
      p1->bHaveRowid = 0;
      p1->iPrevPage = -1;
      p1->iPrevCell = -1;
    }else{
      return SQLITE_DONE;
    }
  }
  assert( p->errCode!=SQLITE_OK || p1->pTab );

  if( p->errCode==SQLITE_OK && sqlite3_step(pSel)==SQLITE_ROW ){
    RecoverTable *pTab = p1->pTab;

    i64 iPage = sqlite3_column_int64(pSel, 0);
    int iCell = sqlite3_column_int(pSel, 1);
    int iField = sqlite3_column_int(pSel, 2);
    sqlite3_value *pVal = sqlite3_column_value(pSel, 3);
    int bNewCell = (p1->iPrevPage!=iPage || p1->iPrevCell!=iCell);

    assert( bNewCell==0 || (iField==-1 || iField==0) );
    assert( bNewCell || iField==p1->nVal || p1->nVal==pTab->nCol );

    if( bNewCell ){
      int ii = 0;
      if( p1->nVal>=0 ){
        if( p1->pInsert==0 || p1->nVal!=p1->nInsert ){
          recoverFinalize(p, p1->pInsert);
          p1->pInsert = recoverInsertStmt(p, pTab, p1->nVal);
          p1->nInsert = p1->nVal;
        }
        if( p1->nVal>0 ){
          sqlite3_stmt *pInsert = p1->pInsert;
          for(ii=0; ii<pTab->nCol; ii++){
            RecoverColumn *pCol = &pTab->aCol[ii];
            int iBind = pCol->iBind;
            if( iBind>0 ){
              if( pCol->bIPK ){
                sqlite3_bind_int64(pInsert, iBind, p1->iRowid);
              }else if( pCol->iField<p1->nVal ){
                recoverBindValue(p, pInsert, iBind, apVal[pCol->iField]);
              }
            }
          }
          if( p->bRecoverRowid && pTab->iRowidBind>0 && p1->bHaveRowid ){
            sqlite3_bind_int64(pInsert, pTab->iRowidBind, p1->iRowid);
          }
          if( SQLITE_ROW==sqlite3_step(pInsert) ){
            const char *z = (const char*)sqlite3_column_text(pInsert, 0);
            recoverSqlCallback(p, z);
          }
          recoverReset(p, pInsert);
          assert( p->errCode || pInsert );
          if( pInsert ) sqlite3_clear_bindings(pInsert);
        }
      }

      for(ii=0; ii<p1->nVal; ii++){
        sqlite3_value_free(apVal[ii]);
        apVal[ii] = 0;
      }
      p1->nVal = -1;
      p1->bHaveRowid = 0;
    }

    if( iPage!=0 ){
      if( iField<0 ){
        p1->iRowid = sqlite3_column_int64(pSel, 3);
        assert( p1->nVal==-1 );
        p1->nVal = 0;
        p1->bHaveRowid = 1;
      }else if( iField<pTab->nCol ){
        assert( apVal[iField]==0 );
        apVal[iField] = sqlite3_value_dup( pVal );
        if( apVal[iField]==0 ){
          recoverError(p, SQLITE_NOMEM, 0);
        }
        p1->nVal = iField+1;
      }else if( pTab->nCol==0 ){
        p1->nVal = pTab->nCol;
      }
      p1->iPrevCell = iCell;
      p1->iPrevPage = iPage;
    }
  }else{
    recoverReset(p, pSel);
    p1->pTab = 0;
  }

  return p->errCode;
}

/*
** Initialize resources required by sqlite3_recover_step() in
** RECOVER_STATE_LOSTANDFOUND1 state - during which the set of pages not
** already allocated to a recovered schema element is determined.
*/ 
static void recoverLostAndFound1Init(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  sqlite3_stmt *pStmt = 0;

  assert( p->laf.pUsed==0 );
  pLaf->nPg = recoverPageCount(p);
  pLaf->pUsed = recoverBitmapAlloc(p, pLaf->nPg);

  /* Prepare a statement to iterate through all pages that are part of any tree
  ** in the recoverable part of the input database schema to the bitmap. And,
  ** if !p->bFreelistCorrupt, add all pages that appear to be part of the
  ** freelist.  */
  pStmt = recoverPrepare(
      p, p->dbOut,
      "WITH trunk(pgno) AS ("
      "  SELECT read_i32(getpage(1), 8) AS x WHERE x>0"
      "    UNION"
      "  SELECT read_i32(getpage(trunk.pgno), 0) AS x FROM trunk WHERE x>0"
      "),"
      "trunkdata(pgno, data) AS ("
      "  SELECT pgno, getpage(pgno) FROM trunk"
      "),"
      "freelist(data, n, freepgno) AS ("
      "  SELECT data, min(16384, read_i32(data, 1)-1), pgno FROM trunkdata"
      "    UNION ALL"
      "  SELECT data, n-1, read_i32(data, 2+n) FROM freelist WHERE n>=0"
      "),"
      ""
      "roots(r) AS ("
      "  SELECT 1 UNION ALL"
      "  SELECT rootpage FROM recovery.schema WHERE rootpage>0"
      "),"
      "used(page) AS ("
      "  SELECT r FROM roots"
      "    UNION"
      "  SELECT child FROM sqlite_dbptr('getpage()'), used "
      "    WHERE pgno=page"
      ") "
      "SELECT page FROM used"
      " UNION ALL "
      "SELECT freepgno FROM freelist WHERE NOT ?"
  );
  if( pStmt ) sqlite3_bind_int(pStmt, 1, p->bFreelistCorrupt);
  pLaf->pUsedPages = pStmt;
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_LOSTANDFOUND1 state - during which the set of pages not
** already allocated to a recovered schema element is determined.
*/ 
static int recoverLostAndFound1Step(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  int rc = p->errCode;
  if( rc==SQLITE_OK ){
    rc = sqlite3_step(pLaf->pUsedPages);
    if( rc==SQLITE_ROW ){
      i64 iPg = sqlite3_column_int64(pLaf->pUsedPages, 0);
      recoverBitmapSet(pLaf->pUsed, iPg);
      rc = SQLITE_OK;
    }else{
      recoverFinalize(p, pLaf->pUsedPages);
      pLaf->pUsedPages = 0;
    }
  }
  return rc;
}

/*
** Initialize resources required by RECOVER_STATE_LOSTANDFOUND2 
** state - during which the pages identified in RECOVER_STATE_LOSTANDFOUND1
** are sorted into sets that likely belonged to the same database tree.
*/ 
static void recoverLostAndFound2Init(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;

  assert( p->laf.pAllAndParent==0 );
  assert( p->laf.pMapInsert==0 );
  assert( p->laf.pMaxField==0 );
  assert( p->laf.nMaxField==0 );

  pLaf->pMapInsert = recoverPrepare(p, p->dbOut,
      "INSERT OR IGNORE INTO recovery.map(pgno, parent) VALUES(?, ?)"
  );
  pLaf->pAllAndParent = recoverPreparePrintf(p, p->dbOut,
      "WITH RECURSIVE seq(ii) AS ("
      "  SELECT 1 UNION ALL SELECT ii+1 FROM seq WHERE ii<%lld"
      ")"
      "SELECT pgno, child FROM sqlite_dbptr('getpage()') "
      " UNION ALL "
      "SELECT NULL, ii FROM seq", p->laf.nPg
  );
  pLaf->pMaxField = recoverPreparePrintf(p, p->dbOut,
      "SELECT max(field)+1 FROM sqlite_dbdata('getpage') WHERE pgno = ?"
  );
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_LOSTANDFOUND2 state - during which the pages identified 
** in RECOVER_STATE_LOSTANDFOUND1 are sorted into sets that likely belonged 
** to the same database tree.
*/ 
static int recoverLostAndFound2Step(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  if( p->errCode==SQLITE_OK ){
    int res = sqlite3_step(pLaf->pAllAndParent);
    if( res==SQLITE_ROW ){
      i64 iChild = sqlite3_column_int(pLaf->pAllAndParent, 1);
      if( recoverBitmapQuery(pLaf->pUsed, iChild)==0 ){
        sqlite3_bind_int64(pLaf->pMapInsert, 1, iChild);
        sqlite3_bind_value(pLaf->pMapInsert, 2, 
            sqlite3_column_value(pLaf->pAllAndParent, 0)
        );
        sqlite3_step(pLaf->pMapInsert);
        recoverReset(p, pLaf->pMapInsert);
        sqlite3_bind_int64(pLaf->pMaxField, 1, iChild);
        if( SQLITE_ROW==sqlite3_step(pLaf->pMaxField) ){
          int nMax = sqlite3_column_int(pLaf->pMaxField, 0);
          if( nMax>pLaf->nMaxField ) pLaf->nMaxField = nMax;
        }
        recoverReset(p, pLaf->pMaxField);
      }
    }else{
      recoverFinalize(p, pLaf->pAllAndParent);
      pLaf->pAllAndParent =0;
      return SQLITE_DONE;
    }
  }
  return p->errCode;
}

/*
** Free all resources allocated as part of sqlite3_recover_step() calls
** in one of the RECOVER_STATE_LOSTANDFOUND[123] states.
*/
static void recoverLostAndFoundCleanup(sqlite3_recover *p){
  recoverBitmapFree(p->laf.pUsed);
  p->laf.pUsed = 0;
  sqlite3_finalize(p->laf.pUsedPages);
  sqlite3_finalize(p->laf.pAllAndParent);
  sqlite3_finalize(p->laf.pMapInsert);
  sqlite3_finalize(p->laf.pMaxField);
  sqlite3_finalize(p->laf.pFindRoot);
  sqlite3_finalize(p->laf.pInsert);
  sqlite3_finalize(p->laf.pAllPage);
  sqlite3_finalize(p->laf.pPageData);
  p->laf.pUsedPages = 0;
  p->laf.pAllAndParent = 0;
  p->laf.pMapInsert = 0;
  p->laf.pMaxField = 0;
  p->laf.pFindRoot = 0;
  p->laf.pInsert = 0;
  p->laf.pAllPage = 0;
  p->laf.pPageData = 0;
  sqlite3_free(p->laf.apVal);
  p->laf.apVal = 0;
}

/*
** Free all resources allocated as part of sqlite3_recover_step() calls.
*/
static void recoverFinalCleanup(sqlite3_recover *p){
  RecoverTable *pTab = 0;
  RecoverTable *pNext = 0;

  recoverWriteDataCleanup(p);
  recoverLostAndFoundCleanup(p);

  for(pTab=p->pTblList; pTab; pTab=pNext){
    pNext = pTab->pNext;
    sqlite3_free(pTab);
  }
  p->pTblList = 0;
  sqlite3_finalize(p->pGetPage);
  p->pGetPage = 0;
  sqlite3_file_control(p->dbIn, p->zDb, SQLITE_FCNTL_RESET_CACHE, 0);

  {
#ifndef NDEBUG
    int res = 
#endif
       sqlite3_close(p->dbOut);
    assert( res==SQLITE_OK );
  }
  p->dbOut = 0;
}

/*
** Decode and return an unsigned 16-bit big-endian integer value from 
** buffer a[].
*/
static u32 recoverGetU16(const u8 *a){
  return (((u32)a[0])<<8) + ((u32)a[1]);
}

/*
** Decode and return an unsigned 32-bit big-endian integer value from 
** buffer a[].
*/
static u32 recoverGetU32(const u8 *a){
  return (((u32)a[0])<<24) + (((u32)a[1])<<16) + (((u32)a[2])<<8) + ((u32)a[3]);
}

/*
** Decode an SQLite varint from buffer a[]. Write the decoded value to (*pVal)
** and return the number of bytes consumed.
*/
static int recoverGetVarint(const u8 *a, i64 *pVal){
  sqlite3_uint64 u = 0;
  int i;
  for(i=0; i<8; i++){
    u = (u<<7) + (a[i]&0x7f);
    if( (a[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; }
  }
  u = (u<<8) + (a[i]&0xff);
  *pVal = (sqlite3_int64)u;
  return 9;
}

/*
** The second argument points to a buffer n bytes in size. If this buffer
** or a prefix thereof appears to contain a well-formed SQLite b-tree page, 
** return the page-size in bytes. Otherwise, if the buffer does not 
** appear to contain a well-formed b-tree page, return 0.
*/
static int recoverIsValidPage(u8 *aTmp, const u8 *a, int n){
  u8 *aUsed = aTmp;
  int nFrag = 0;
  int nActual = 0;
  int iFree = 0;
  int nCell = 0;                  /* Number of cells on page */
  int iCellOff = 0;               /* Offset of cell array in page */
  int iContent = 0;
  int eType = 0;
  int ii = 0;

  eType = (int)a[0];
  if( eType!=0x02 && eType!=0x05 && eType!=0x0A && eType!=0x0D ) return 0;

  iFree = (int)recoverGetU16(&a[1]);
  nCell = (int)recoverGetU16(&a[3]);
  iContent = (int)recoverGetU16(&a[5]);
  if( iContent==0 ) iContent = 65536;
  nFrag = (int)a[7];

  if( iContent>n ) return 0;

  memset(aUsed, 0, n);
  memset(aUsed, 0xFF, iContent);

  /* Follow the free-list. This is the same format for all b-tree pages. */
  if( iFree && iFree<=iContent ) return 0;
  while( iFree ){
    int iNext = 0;
    int nByte = 0;
    if( iFree>(n-4) ) return 0;
    iNext = recoverGetU16(&a[iFree]);
    nByte = recoverGetU16(&a[iFree+2]);
    if( iFree+nByte>n || nByte<4 ) return 0;
    if( iNext && iNext<iFree+nByte ) return 0;
    memset(&aUsed[iFree], 0xFF, nByte);
    iFree = iNext;
  }

  /* Run through the cells */
  if( eType==0x02 || eType==0x05 ){
    iCellOff = 12;
  }else{
    iCellOff = 8;
  }
  if( (iCellOff + 2*nCell)>iContent ) return 0;
  for(ii=0; ii<nCell; ii++){
    int iByte;
    i64 nPayload = 0;
    int nByte = 0;
    int iOff = recoverGetU16(&a[iCellOff + 2*ii]);
    if( iOff<iContent || iOff>n ){
      return 0;
    }
    if( eType==0x05 || eType==0x02 ) nByte += 4;
    nByte += recoverGetVarint(&a[iOff+nByte], &nPayload);
    if( eType==0x0D ){
      i64 dummy = 0;
      nByte += recoverGetVarint(&a[iOff+nByte], &dummy);
    }
    if( eType!=0x05 ){
      int X = (eType==0x0D) ? n-35 : (((n-12)*64/255)-23);
      int M = ((n-12)*32/255)-23;
      int K = M+((nPayload-M)%(n-4));

      if( nPayload<X ){
        nByte += nPayload;
      }else if( K<=X ){
        nByte += K+4;
      }else{
        nByte += M+4;
      }
    }

    if( iOff+nByte>n ){
      return 0;
    }
    for(iByte=iOff; iByte<(iOff+nByte); iByte++){
      if( aUsed[iByte]!=0 ){
        return 0;
      }
      aUsed[iByte] = 0xFF;
    }
  }

  nActual = 0;
  for(ii=0; ii<n; ii++){
    if( aUsed[ii]==0 ) nActual++;
  }
  return (nActual==nFrag);
}


static int recoverVfsClose(sqlite3_file*);
static int recoverVfsRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int recoverVfsWrite(sqlite3_file*, const void*, int, sqlite3_int64);
static int recoverVfsTruncate(sqlite3_file*, sqlite3_int64 size);
static int recoverVfsSync(sqlite3_file*, int flags);
static int recoverVfsFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int recoverVfsLock(sqlite3_file*, int);
static int recoverVfsUnlock(sqlite3_file*, int);
static int recoverVfsCheckReservedLock(sqlite3_file*, int *pResOut);
static int recoverVfsFileControl(sqlite3_file*, int op, void *pArg);
static int recoverVfsSectorSize(sqlite3_file*);
static int recoverVfsDeviceCharacteristics(sqlite3_file*);
static int recoverVfsShmMap(sqlite3_file*, int, int, int, void volatile**);
static int recoverVfsShmLock(sqlite3_file*, int offset, int n, int flags);
static void recoverVfsShmBarrier(sqlite3_file*);
static int recoverVfsShmUnmap(sqlite3_file*, int deleteFlag);
static int recoverVfsFetch(sqlite3_file*, sqlite3_int64, int, void**);
static int recoverVfsUnfetch(sqlite3_file *pFd, sqlite3_int64 iOff, void *p);

static sqlite3_io_methods recover_methods = {
  2, /* iVersion */
  recoverVfsClose,
  recoverVfsRead,
  recoverVfsWrite,
  recoverVfsTruncate,
  recoverVfsSync,
  recoverVfsFileSize,
  recoverVfsLock,
  recoverVfsUnlock,
  recoverVfsCheckReservedLock,
  recoverVfsFileControl,
  recoverVfsSectorSize,
  recoverVfsDeviceCharacteristics,
  recoverVfsShmMap,
  recoverVfsShmLock,
  recoverVfsShmBarrier,
  recoverVfsShmUnmap,
  recoverVfsFetch,
  recoverVfsUnfetch
};

static int recoverVfsClose(sqlite3_file *pFd){
  assert( pFd->pMethods!=&recover_methods );
  return pFd->pMethods->xClose(pFd);
}

/*
** Write value v to buffer a[] as a 16-bit big-endian unsigned integer.
*/
static void recoverPutU16(u8 *a, u32 v){
  a[0] = (v>>8) & 0x00FF;
  a[1] = (v>>0) & 0x00FF;
}

/*
** Write value v to buffer a[] as a 32-bit big-endian unsigned integer.
*/
static void recoverPutU32(u8 *a, u32 v){
  a[0] = (v>>24) & 0x00FF;
  a[1] = (v>>16) & 0x00FF;
  a[2] = (v>>8) & 0x00FF;
  a[3] = (v>>0) & 0x00FF;
}

/*
** Detect the page-size of the database opened by file-handle pFd by 
** searching the first part of the file for a well-formed SQLite b-tree 
** page. If parameter nReserve is non-zero, then as well as searching for
** a b-tree page with zero reserved bytes, this function searches for one
** with nReserve reserved bytes at the end of it.
**
** If successful, set variable p->detected_pgsz to the detected page-size
** in bytes and return SQLITE_OK. Or, if no error occurs but no valid page
** can be found, return SQLITE_OK but leave p->detected_pgsz set to 0. Or,
** if an error occurs (e.g. an IO or OOM error), then an SQLite error code
** is returned. The final value of p->detected_pgsz is undefined in this
** case.
*/
static int recoverVfsDetectPagesize(
  sqlite3_recover *p,             /* Recover handle */
  sqlite3_file *pFd,              /* File-handle open on input database */
  u32 nReserve,                   /* Possible nReserve value */
  i64 nSz                         /* Size of database file in bytes */
){
  int rc = SQLITE_OK;
  const int nMin = 512;
  const int nMax = 65536;
  const int nMaxBlk = 4;
  u32 pgsz = 0;
  int iBlk = 0;
  u8 *aPg = 0;
  u8 *aTmp = 0;
  int nBlk = 0;

  aPg = (u8*)sqlite3_malloc(2*nMax);
  if( aPg==0 ) return SQLITE_NOMEM;
  aTmp = &aPg[nMax];

  nBlk = (nSz+nMax-1)/nMax;
  if( nBlk>nMaxBlk ) nBlk = nMaxBlk;

  do {
    for(iBlk=0; rc==SQLITE_OK && iBlk<nBlk; iBlk++){
      int nByte = (nSz>=((iBlk+1)*nMax)) ? nMax : (nSz % nMax);
      memset(aPg, 0, nMax);
      rc = pFd->pMethods->xRead(pFd, aPg, nByte, iBlk*nMax);
      if( rc==SQLITE_OK ){
        int pgsz2;
        for(pgsz2=(pgsz ? pgsz*2 : nMin); pgsz2<=nMax; pgsz2=pgsz2*2){
          int iOff;
          for(iOff=0; iOff<nMax; iOff+=pgsz2){
            if( recoverIsValidPage(aTmp, &aPg[iOff], pgsz2-nReserve) ){
              pgsz = pgsz2;
              break;
            }
          }
        }
      }
    }
    if( pgsz>(u32)p->detected_pgsz ){
      p->detected_pgsz = pgsz;
      p->nReserve = nReserve;
    }
    if( nReserve==0 ) break;
    nReserve = 0;
  }while( 1 );

  p->detected_pgsz = pgsz;
  sqlite3_free(aPg);
  return rc;
}

/*
** The xRead() method of the wrapper VFS. This is used to intercept calls
** to read page 1 of the input database.
*/
static int recoverVfsRead(sqlite3_file *pFd, void *aBuf, int nByte, i64 iOff){
  int rc = SQLITE_OK;
  if( pFd->pMethods==&recover_methods ){
    pFd->pMethods = recover_g.pMethods;
    rc = pFd->pMethods->xRead(pFd, aBuf, nByte, iOff);
    if( nByte==16 ){
      sqlite3_randomness(16, aBuf);
    }else
    if( rc==SQLITE_OK && iOff==0 && nByte>=108 ){
      /* Ensure that the database has a valid header file. The only fields
      ** that really matter to recovery are:
      **
      **   + Database page size (16-bits at offset 16)
      **   + Size of db in pages (32-bits at offset 28)
      **   + Database encoding (32-bits at offset 56)
      **
      ** Also preserved are:
      **
      **   + first freelist page (32-bits at offset 32)
      **   + size of freelist (32-bits at offset 36)
      **   + the wal-mode flags (16-bits at offset 18)
      **
      ** We also try to preserve the auto-vacuum, incr-value, user-version
      ** and application-id fields - all 32 bit quantities at offsets 
      ** 52, 60, 64 and 68. All other fields are set to known good values.
      **
      ** Byte offset 105 should also contain the page-size as a 16-bit 
      ** integer.
      */
      const int aPreserve[] = {32, 36, 52, 60, 64, 68};
      u8 aHdr[108] = {
        0x53, 0x51, 0x4c, 0x69, 0x74, 0x65, 0x20, 0x66, 
        0x6f, 0x72, 0x6d, 0x61, 0x74, 0x20, 0x33, 0x00,
        0xFF, 0xFF, 0x01, 0x01, 0x00, 0x40, 0x20, 0x20,
        0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
        0x00, 0x00, 0x10, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x2e, 0x5b, 0x30,

        0x0D, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00
      };
      u8 *a = (u8*)aBuf;

      u32 pgsz = recoverGetU16(&a[16]);
      u32 nReserve = a[20];
      u32 enc = recoverGetU32(&a[56]);
      u32 dbsz = 0;
      i64 dbFileSize = 0;
      int ii;
      sqlite3_recover *p = recover_g.p;

      if( pgsz==0x01 ) pgsz = 65536;
      rc = pFd->pMethods->xFileSize(pFd, &dbFileSize);

      if( rc==SQLITE_OK && p->detected_pgsz==0 ){
        rc = recoverVfsDetectPagesize(p, pFd, nReserve, dbFileSize);
      }
      if( p->detected_pgsz ){
        pgsz = p->detected_pgsz;
        nReserve = p->nReserve;
      }

      if( pgsz ){
        dbsz = dbFileSize / pgsz;
      }
      if( enc!=SQLITE_UTF8 && enc!=SQLITE_UTF16BE && enc!=SQLITE_UTF16LE ){
        enc = SQLITE_UTF8;
      }

      sqlite3_free(p->pPage1Cache);
      p->pPage1Cache = 0;
      p->pPage1Disk = 0;

      p->pgsz = nByte;
      p->pPage1Cache = (u8*)recoverMalloc(p, nByte*2);
      if( p->pPage1Cache ){
        p->pPage1Disk = &p->pPage1Cache[nByte];
        memcpy(p->pPage1Disk, aBuf, nByte);
        aHdr[18] = a[18];
        aHdr[19] = a[19];
        recoverPutU32(&aHdr[28], dbsz);
        recoverPutU32(&aHdr[56], enc);
        recoverPutU16(&aHdr[105], pgsz-nReserve);
        if( pgsz==65536 ) pgsz = 1;
        recoverPutU16(&aHdr[16], pgsz);
        aHdr[20] = nReserve;
        for(ii=0; ii<(int)(sizeof(aPreserve)/sizeof(aPreserve[0])); ii++){
          memcpy(&aHdr[aPreserve[ii]], &a[aPreserve[ii]], 4);
        }
        memcpy(aBuf, aHdr, sizeof(aHdr));
        memset(&((u8*)aBuf)[sizeof(aHdr)], 0, nByte-sizeof(aHdr));

        memcpy(p->pPage1Cache, aBuf, nByte);
      }else{
        rc = p->errCode;
      }

    }
    pFd->pMethods = &recover_methods;
  }else{
    rc = pFd->pMethods->xRead(pFd, aBuf, nByte, iOff);
  }
  return rc;
}

/*
** Used to make sqlite3_io_methods wrapper methods less verbose.
*/
#define RECOVER_VFS_WRAPPER(code)                         \
  int rc = SQLITE_OK;                                     \
  if( pFd->pMethods==&recover_methods ){                  \
    pFd->pMethods = recover_g.pMethods;                   \
    rc = code;                                            \
    pFd->pMethods = &recover_methods;                     \
  }else{                                                  \
    rc = code;                                            \
  }                                                       \
  return rc;                                              

/*
** Methods of the wrapper VFS. All methods except for xRead() and xClose()
** simply uninstall the sqlite3_io_methods wrapper, invoke the equivalent
** method on the lower level VFS, then reinstall the wrapper before returning.
** Those that return an integer value use the RECOVER_VFS_WRAPPER macro.
*/
static int recoverVfsWrite(
  sqlite3_file *pFd, const void *aBuf, int nByte, i64 iOff
){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xWrite(pFd, aBuf, nByte, iOff)
  );
}
static int recoverVfsTruncate(sqlite3_file *pFd, sqlite3_int64 size){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xTruncate(pFd, size)
  );
}
static int recoverVfsSync(sqlite3_file *pFd, int flags){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xSync(pFd, flags)
  );
}
static int recoverVfsFileSize(sqlite3_file *pFd, sqlite3_int64 *pSize){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xFileSize(pFd, pSize)
  );
}
static int recoverVfsLock(sqlite3_file *pFd, int eLock){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xLock(pFd, eLock)
  );
}
static int recoverVfsUnlock(sqlite3_file *pFd, int eLock){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xUnlock(pFd, eLock)
  );
}
static int recoverVfsCheckReservedLock(sqlite3_file *pFd, int *pResOut){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xCheckReservedLock(pFd, pResOut)
  );
}
static int recoverVfsFileControl(sqlite3_file *pFd, int op, void *pArg){
  RECOVER_VFS_WRAPPER (
    (pFd->pMethods ?  pFd->pMethods->xFileControl(pFd, op, pArg) : SQLITE_NOTFOUND)
  );
}
static int recoverVfsSectorSize(sqlite3_file *pFd){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xSectorSize(pFd)
  );
}
static int recoverVfsDeviceCharacteristics(sqlite3_file *pFd){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xDeviceCharacteristics(pFd)
  );
}
static int recoverVfsShmMap(
  sqlite3_file *pFd, int iPg, int pgsz, int bExtend, void volatile **pp
){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xShmMap(pFd, iPg, pgsz, bExtend, pp)
  );
}
static int recoverVfsShmLock(sqlite3_file *pFd, int offset, int n, int flags){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xShmLock(pFd, offset, n, flags)
  );
}
static void recoverVfsShmBarrier(sqlite3_file *pFd){
  if( pFd->pMethods==&recover_methods ){
    pFd->pMethods = recover_g.pMethods;
    pFd->pMethods->xShmBarrier(pFd);
    pFd->pMethods = &recover_methods;
  }else{
    pFd->pMethods->xShmBarrier(pFd);
  }
}
static int recoverVfsShmUnmap(sqlite3_file *pFd, int deleteFlag){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xShmUnmap(pFd, deleteFlag)
  );
}

static int recoverVfsFetch(
  sqlite3_file *pFd, 
  sqlite3_int64 iOff, 
  int iAmt, 
  void **pp
){
  (void)pFd;
  (void)iOff;
  (void)iAmt;
  *pp = 0;
  return SQLITE_OK;
}
static int recoverVfsUnfetch(sqlite3_file *pFd, sqlite3_int64 iOff, void *p){
  (void)pFd;
  (void)iOff;
  (void)p;
  return SQLITE_OK;
}

/*
** Install the VFS wrapper around the file-descriptor open on the input
** database for recover handle p. Mutex RECOVER_MUTEX_ID must be held
** when this function is called.
*/
static void recoverInstallWrapper(sqlite3_recover *p){
  sqlite3_file *pFd = 0;
  assert( recover_g.pMethods==0 );
  recoverAssertMutexHeld();
  sqlite3_file_control(p->dbIn, p->zDb, SQLITE_FCNTL_FILE_POINTER, (void*)&pFd);
  assert( pFd==0 || pFd->pMethods!=&recover_methods );
  if( pFd && pFd->pMethods ){
    int iVersion = 1 + (pFd->pMethods->iVersion>1 && pFd->pMethods->xShmMap!=0);
    recover_g.pMethods = pFd->pMethods;
    recover_g.p = p;
    recover_methods.iVersion = iVersion;
    pFd->pMethods = &recover_methods;
  }
}

/*
** Uninstall the VFS wrapper that was installed around the file-descriptor open
** on the input database for recover handle p. Mutex RECOVER_MUTEX_ID must be
** held when this function is called.
*/
static void recoverUninstallWrapper(sqlite3_recover *p){
  sqlite3_file *pFd = 0;
  recoverAssertMutexHeld();
  sqlite3_file_control(p->dbIn, p->zDb,SQLITE_FCNTL_FILE_POINTER,(void*)&pFd);
  if( pFd && pFd->pMethods ){
    pFd->pMethods = recover_g.pMethods;
    recover_g.pMethods = 0;
    recover_g.p = 0;
  }
}

/*
** This function does the work of a single sqlite3_recover_step() call. It
** is guaranteed that the handle is not in an error state when this
** function is called.
*/
static void recoverStep(sqlite3_recover *p){
  assert( p && p->errCode==SQLITE_OK );
  switch( p->eState ){
    case RECOVER_STATE_INIT: {
      int bUseWrapper = 1;
      /* This is the very first call to sqlite3_recover_step() on this object.
      */
      recoverSqlCallback(p, "BEGIN");
      recoverSqlCallback(p, "PRAGMA writable_schema = on");
      recoverSqlCallback(p, "PRAGMA foreign_keys = off");

      recoverEnterMutex();

      /* Open the output database. And register required virtual tables and 
      ** user functions with the new handle. */
      recoverOpenOutput(p);

      /* Attempt to open a transaction and read page 1 of the input database.
      ** Two attempts may be made - one with a wrapper installed to ensure
      ** that the database header is sane, and then if that attempt returns
      ** SQLITE_NOTADB, then again with no wrapper. The second attempt is
      ** required for encrypted databases.  */
      if( p->errCode==SQLITE_OK ){
        do{
          p->errCode = SQLITE_OK;
          if( bUseWrapper ) recoverInstallWrapper(p);

          /* Open a transaction on the input database. */
          sqlite3_file_control(p->dbIn, p->zDb, SQLITE_FCNTL_RESET_CACHE, 0);
          recoverExec(p, p->dbIn, "PRAGMA writable_schema = on");
          recoverExec(p, p->dbIn, "BEGIN");
          if( p->errCode==SQLITE_OK ) p->bCloseTransaction = 1;
          recoverExec(p, p->dbIn, "SELECT 1 FROM sqlite_schema");
          recoverTransferSettings(p);
          recoverOpenRecovery(p);
          recoverCacheSchema(p);

          if( bUseWrapper ) recoverUninstallWrapper(p);
        }while( p->errCode==SQLITE_NOTADB 
             && (bUseWrapper--) 
             && SQLITE_OK==sqlite3_exec(p->dbIn, "ROLLBACK", 0, 0, 0)
        );
      }

      recoverLeaveMutex();
      recoverExec(p, p->dbOut, "BEGIN");
      recoverWriteSchema1(p);
      p->eState = RECOVER_STATE_WRITING;
      break;
    }
      
    case RECOVER_STATE_WRITING: {
      if( p->w1.pTbls==0 ){
        recoverWriteDataInit(p);
      }
      if( SQLITE_DONE==recoverWriteDataStep(p) ){
        recoverWriteDataCleanup(p);
        if( p->zLostAndFound ){
          p->eState = RECOVER_STATE_LOSTANDFOUND1;
        }else{
          p->eState = RECOVER_STATE_SCHEMA2;
        }
      }
      break;
    }

    case RECOVER_STATE_LOSTANDFOUND1: {
      if( p->laf.pUsed==0 ){
        recoverLostAndFound1Init(p);
      }
      if( SQLITE_DONE==recoverLostAndFound1Step(p) ){
        p->eState = RECOVER_STATE_LOSTANDFOUND2;
      }
      break;
    }
    case RECOVER_STATE_LOSTANDFOUND2: {
      if( p->laf.pAllAndParent==0 ){
        recoverLostAndFound2Init(p);
      }
      if( SQLITE_DONE==recoverLostAndFound2Step(p) ){
        p->eState = RECOVER_STATE_LOSTANDFOUND3;
      }
      break;
    }

    case RECOVER_STATE_LOSTANDFOUND3: {
      if( p->laf.pInsert==0 ){
        recoverLostAndFound3Init(p);
      }
      if( SQLITE_DONE==recoverLostAndFound3Step(p) ){
        p->eState = RECOVER_STATE_SCHEMA2;
      }
      break;
    }

    case RECOVER_STATE_SCHEMA2: {
      int rc = SQLITE_OK;

      recoverWriteSchema2(p);
      p->eState = RECOVER_STATE_DONE;

      /* If no error has occurred, commit the write transaction on the output
      ** database. Regardless of whether or not an error has occurred, make
      ** an attempt to end the read transaction on the input database.  */
      recoverExec(p, p->dbOut, "COMMIT");
      rc = sqlite3_exec(p->dbIn, "END", 0, 0, 0);
      if( p->errCode==SQLITE_OK ) p->errCode = rc;

      recoverSqlCallback(p, "PRAGMA writable_schema = off");
      recoverSqlCallback(p, "COMMIT");
      p->eState = RECOVER_STATE_DONE;
      recoverFinalCleanup(p);
      break;
    };

    case RECOVER_STATE_DONE: {
      /* no-op */
      break;
    };
  }
}


/*
** This is a worker function that does the heavy lifting for both init
** functions:
**
**     sqlite3_recover_init()
**     sqlite3_recover_init_sql()
**
** All this function does is allocate space for the recover handle and
** take copies of the input parameters. All the real work is done within
** sqlite3_recover_run().
*/
sqlite3_recover *recoverInit(
  sqlite3* db, 
  const char *zDb, 
  const char *zUri,               /* Output URI for _recover_init() */
  int (*xSql)(void*, const char*),/* SQL callback for _recover_init_sql() */
  void *pSqlCtx                   /* Context arg for _recover_init_sql() */
){
  sqlite3_recover *pRet = 0;
  int nDb = 0;
  int nUri = 0;
  int nByte = 0;

  if( zDb==0 ){ zDb = "main"; }

  nDb = recoverStrlen(zDb);
  nUri = recoverStrlen(zUri);

  nByte = sizeof(sqlite3_recover) + nDb+1 + nUri+1;
  pRet = (sqlite3_recover*)sqlite3_malloc(nByte);
  if( pRet ){
    memset(pRet, 0, nByte);
    pRet->dbIn = db;
    pRet->zDb = (char*)&pRet[1];
    pRet->zUri = &pRet->zDb[nDb+1];
    memcpy(pRet->zDb, zDb, nDb);
    if( nUri>0 && zUri ) memcpy(pRet->zUri, zUri, nUri);
    pRet->xSql = xSql;
    pRet->pSqlCtx = pSqlCtx;
    pRet->bRecoverRowid = RECOVER_ROWID_DEFAULT;
  }

  return pRet;
}

/*
** Initialize a recovery handle that creates a new database containing
** the recovered data.
*/
sqlite3_recover *sqlite3_recover_init(
  sqlite3* db, 
  const char *zDb, 
  const char *zUri
){
  return recoverInit(db, zDb, zUri, 0, 0);
}

/*
** Initialize a recovery handle that returns recovered data in the
** form of SQL statements via a callback.
*/
sqlite3_recover *sqlite3_recover_init_sql(
  sqlite3* db, 
  const char *zDb, 
  int (*xSql)(void*, const char*),
  void *pSqlCtx
){
  return recoverInit(db, zDb, 0, xSql, pSqlCtx);
}

/*
** Return the handle error message, if any.
*/
const char *sqlite3_recover_errmsg(sqlite3_recover *p){
  return (p && p->errCode!=SQLITE_NOMEM) ? p->zErrMsg : "out of memory";
}

/*
** Return the handle error code.
*/
int sqlite3_recover_errcode(sqlite3_recover *p){
  return p ? p->errCode : SQLITE_NOMEM;
}

/*
** Configure the handle.
*/
int sqlite3_recover_config(sqlite3_recover *p, int op, void *pArg){
  int rc = SQLITE_OK;
  if( p==0 ){
    rc = SQLITE_NOMEM;
  }else if( p->eState!=RECOVER_STATE_INIT ){
    rc = SQLITE_MISUSE;
  }else{
    switch( op ){
      case 789:
        /* This undocumented magic configuration option is used to set the
        ** name of the auxiliary database that is ATTACH-ed to the database
        ** connection and used to hold state information during the
        ** recovery process.  This option is for debugging use only and
        ** is subject to change or removal at any time. */
        sqlite3_free(p->zStateDb);
        p->zStateDb = recoverMPrintf(p, "%s", (char*)pArg);
        break;

      case SQLITE_RECOVER_LOST_AND_FOUND: {
        const char *zArg = (const char*)pArg;
        sqlite3_free(p->zLostAndFound);
        if( zArg ){
          p->zLostAndFound = recoverMPrintf(p, "%s", zArg);
        }else{
          p->zLostAndFound = 0;
        }
        break;
      }

      case SQLITE_RECOVER_FREELIST_CORRUPT:
        p->bFreelistCorrupt = *(int*)pArg;
        break;

      case SQLITE_RECOVER_ROWIDS:
        p->bRecoverRowid = *(int*)pArg;
        break;

      case SQLITE_RECOVER_SLOWINDEXES:
        p->bSlowIndexes = *(int*)pArg;
        break;

      default:
        rc = SQLITE_NOTFOUND;
        break;
    }
  }

  return rc;
}

/*
** Do a unit of work towards the recovery job. Return SQLITE_OK if
** no error has occurred but database recovery is not finished, SQLITE_DONE
** if database recovery has been successfully completed, or an SQLite
** error code if an error has occurred.
*/
int sqlite3_recover_step(sqlite3_recover *p){
  if( p==0 ) return SQLITE_NOMEM;
  if( p->errCode==SQLITE_OK ) recoverStep(p);
  if( p->eState==RECOVER_STATE_DONE && p->errCode==SQLITE_OK ){
    return SQLITE_DONE;
  }
  return p->errCode;
}

/*
** Do the configured recovery operation. Return SQLITE_OK if successful, or
** else an SQLite error code.
*/
int sqlite3_recover_run(sqlite3_recover *p){
  while( SQLITE_OK==sqlite3_recover_step(p) );
  return sqlite3_recover_errcode(p);
}


/*
** Free all resources associated with the recover handle passed as the only
** argument. The results of using a handle with any sqlite3_recover_**
** API function after it has been passed to this function are undefined.
**
** A copy of the value returned by the first call made to sqlite3_recover_run()
** on this handle is returned, or SQLITE_OK if sqlite3_recover_run() has
** not been called on this handle.
*/
int sqlite3_recover_finish(sqlite3_recover *p){
  int rc;
  if( p==0 ){
    rc = SQLITE_NOMEM;
  }else{
    recoverFinalCleanup(p);
    if( p->bCloseTransaction && sqlite3_get_autocommit(p->dbIn)==0 ){
      rc = sqlite3_exec(p->dbIn, "END", 0, 0, 0);
      if( p->errCode==SQLITE_OK ) p->errCode = rc;
    }
    rc = p->errCode;
    sqlite3_free(p->zErrMsg);
    sqlite3_free(p->zStateDb);
    sqlite3_free(p->zLostAndFound);
    sqlite3_free(p->pPage1Cache);
    sqlite3_free(p);
  }
  return rc;
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/************************* End ext/recover/sqlite3recover.c ********************/
# endif /* SQLITE_HAVE_SQLITE3R */
#endif
#ifdef SQLITE_SHELL_EXTSRC
# include SHELL_STRINGIFY(SQLITE_SHELL_EXTSRC)
#endif

#if defined(SQLITE_ENABLE_SESSION)
/*
** State information for a single open session
*/
typedef struct OpenSession OpenSession;
struct OpenSession {
  char *zName;             /* Symbolic name for this session */
  int nFilter;             /* Number of xFilter rejection GLOB patterns */
  char **azFilter;         /* Array of xFilter rejection GLOB patterns */
  sqlite3_session *p;      /* The open session */
};
#endif

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
typedef struct ExpertInfo ExpertInfo;
struct ExpertInfo {
  sqlite3expert *pExpert;
  int bVerbose;
};
#endif

/* All the parameters that determine how to render query results.
*/
typedef struct Mode {
  u8 autoExplain;        /* Automatically turn on .explain mode */
  u8 autoEQP;            /* Run EXPLAIN QUERY PLAN prior to each SQL stmt */
  u8 autoEQPtrace;       /* autoEQP is in trace mode */
  u8 scanstatsOn;        /* True to display scan stats before each finalize */
  u8 bAutoScreenWidth;   /* Using the TTY to determine screen width */
  u8 mFlags;             /* MFLG_ECHO, MFLG_CRLF, etc. */
  u8 eMode;              /* One of the MODE_ values */
  sqlite3_qrf_spec spec; /* Spec to be passed into QRF */
} Mode;

/* Flags for Mode.mFlags */
#define MFLG_ECHO  0x01  /* Echo inputs to output */
#define MFLG_CRLF  0x02  /* Use CR/LF output line endings */
#define MFLG_HDR   0x04  /* .header used to change headers on/off */


/*
** State information about the database connection is contained in an
** instance of the following structure.
*/
typedef struct ShellState ShellState;
struct ShellState {
  sqlite3 *db;           /* The database */
  u8 openMode;           /* SHELL_OPEN_NORMAL, _APPENDVFS, or _ZIPFILE */
  u8 doXdgOpen;          /* Invoke start/open/xdg-open in output_reset() */
  u8 nEqpLevel;          /* Depth of the EQP output graph */
  u8 eTraceType;         /* SHELL_TRACE_* value for type of trace */
  u8 bSafeMode;          /* True to prohibit unsafe operations */
  u8 bSafeModePersist;   /* The long-term value of bSafeMode */
  u8 eRestoreState;      /* See comments above doAutoDetectRestore() */
  unsigned statsOn;      /* True to display memory stats before each finalize */
  unsigned mEqpLines;    /* Mask of vertical lines in the EQP output graph */
  u8 nPopOutput;         /* Revert .output settings when reaching zero */
  u8 nPopMode;           /* Revert .mode settings when reaching zero */
  u8 enableTimer;        /* Enable the timer.  2: permanently 1: only once */
  int inputNesting;      /* Track nesting level of .read and other redirects */
  double prevTimer;      /* Last reported timer value */
  double tmProgress;     /* --timeout option for .progress */
  i64 lineno;            /* Line number of last line read from in */
  const char *zInFile;   /* Name of the input file */
  int openFlags;         /* Additional flags to open.  (SQLITE_OPEN_NOFOLLOW) */
  FILE *in;              /* Read commands from this stream */
  FILE *out;             /* Write results here */
  FILE *traceOut;        /* Output for sqlite3_trace() */
  int nErr;              /* Number of errors seen */
  int writableSchema;    /* True if PRAGMA writable_schema=ON */
  int nCheck;            /* Number of ".check" commands run */
  unsigned nProgress;    /* Number of progress callbacks encountered */
  unsigned mxProgress;   /* Maximum progress callbacks before failing */
  unsigned flgProgress;  /* Flags for the progress callback */
  unsigned shellFlgs;    /* Various flags */
  unsigned nTestRun;     /* Number of test cases run */
  unsigned nTestErr;     /* Number of test cases that failed */
  sqlite3_int64 szMax;   /* --maxsize argument to .open */
  char *zDestTable;      /* Name of destination table when MODE_Insert */
  char *zTempFile;       /* Temporary file that might need deleting */
  char *zErrPrefix;      /* Alternative error message prefix */
  char zTestcase[30];    /* Name of current test case */
  char outfile[FILENAME_MAX]; /* Filename for *out */
  sqlite3_stmt *pStmt;   /* Current statement if any. */
  FILE *pLog;            /* Write log output here */
  Mode mode;             /* Current display mode */
  Mode modePrior;        /* Backup */
  struct SavedMode {     /* Ability to define custom mode configurations */
    char *zTag;            /* Name of this saved mode */
    Mode mode;              /* The saved mode */
  } *aSavedModes;        /* Array of saved .mode settings. system malloc() */
  int nSavedModes;       /* Number of saved .mode settings */
  struct AuxDb {         /* Storage space for auxiliary database connections */
    sqlite3 *db;               /* Connection pointer */
    const char *zDbFilename;   /* Filename used to open the connection */
    char *zFreeOnClose;        /* Free this memory allocation on close */
#if defined(SQLITE_ENABLE_SESSION)
    int nSession;              /* Number of active sessions */
    OpenSession aSession[4];   /* Array of sessions.  [0] is in focus. */
#endif
  } aAuxDb[5],           /* Array of all database connections */
    *pAuxDb;             /* Currently active database connection */
  char *zNonce;          /* Nonce for temporary safe-mode escapes */
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
  ExpertInfo expert;     /* Valid if previous command was ".expert OPT..." */
#endif
  struct DotCmdLine {    /* Info about arguments to a dot-command */
    const char *zOrig;      /* Original text of the dot-command */
    char *zCopy;            /* Copy of zOrig, from malloc() */
    int nAlloc;             /* Size of allocates for arrays below */
    int nArg;               /* Number of argument slots actually used */
    char **azArg;           /* Pointer to each argument, dequoted */
    int *aiOfst;            /* Offset into zOrig[] for start of each arg */
    char *abQuot;           /* True if the argment was originally quoted */
  } dot;
#ifdef SQLITE_SHELL_FIDDLE
  struct {
    const char * zInput; /* Input string from wasm/JS proxy */
    const char * zPos;   /* Cursor pos into zInput */
    const char * zDefaultDbName; /* Default name for db file */
  } wasm;
#endif
};

#ifdef SQLITE_SHELL_FIDDLE
static ShellState shellState;
#endif


/* Allowed values for ShellState.mode.autoEQP
*/
#define AUTOEQP_off      0           /* Automatic EXPLAIN QUERY PLAN is off */
#define AUTOEQP_on       1           /* Automatic EQP is on */
#define AUTOEQP_trigger  2           /* On and also show plans for triggers */
#define AUTOEQP_full     3           /* Show full EXPLAIN */

/* Allowed values for ShellState.openMode
*/
#define SHELL_OPEN_UNSPEC      0      /* No open-mode specified */
#define SHELL_OPEN_NORMAL      1      /* Normal database file */
#define SHELL_OPEN_APPENDVFS   2      /* Use appendvfs */
#define SHELL_OPEN_ZIPFILE     3      /* Use the zipfile virtual table */
#define SHELL_OPEN_DESERIALIZE 4      /* Open using sqlite3_deserialize() */
#define SHELL_OPEN_HEXDB       5      /* Use "dbtotxt" output as data source */

/* Allowed values for ShellState.eTraceType
*/
#define SHELL_TRACE_PLAIN      0      /* Show input SQL text */
#define SHELL_TRACE_EXPANDED   1      /* Show expanded SQL text */
#define SHELL_TRACE_NORMALIZED 2      /* Show normalized SQL text */

/* Bits in the ShellState.flgProgress variable */
#define SHELL_PROGRESS_QUIET 0x01  /* Omit announcing every progress callback */
#define SHELL_PROGRESS_RESET 0x02  /* Reset the count when the progress
                                   ** callback limit is reached, and for each
                                   ** top-level SQL statement */
#define SHELL_PROGRESS_ONCE  0x04  /* Cancel the --limit after firing once */
#define SHELL_PROGRESS_TMOUT 0x08  /* Stop after tmProgress seconds */

/* Names of values for Mode.spec.eEsc and Mode.spec.eText
*/
static const char *qrfEscNames[] = { "auto", "off", "ascii", "symbol" };
static const char *qrfQuoteNames[] = 
      { "off","off","sql","hex","csv","tcl","json","relaxed"};

/*
** These are the allowed shellFlgs values
*/
#define SHFLG_Pagecache      0x00000001 /* The --pagecache option is used */
#define SHFLG_Lookaside      0x00000002 /* Lookaside memory is used */
#define SHFLG_Backslash      0x00000004 /* The --backslash option is used */
#define SHFLG_PreserveRowid  0x00000008 /* .dump preserves rowid values */
#define SHFLG_NoErrLineno    0x00000010 /* Omit line numbers from error msgs */
#define SHFLG_CountChanges   0x00000020 /* .changes setting */
#define SHFLG_DumpDataOnly   0x00000100 /* .dump show data only */
#define SHFLG_DumpNoSys      0x00000200 /* .dump omits system tables */
#define SHFLG_TestingMode    0x00000400 /* allow unsafe testing features */

/*
** Macros for testing and setting shellFlgs
*/
#define ShellHasFlag(P,X)    (((P)->shellFlgs & (X))!=0)
#define ShellSetFlag(P,X)    ((P)->shellFlgs|=(X))
#define ShellClearFlag(P,X)  ((P)->shellFlgs&=(~(X)))

/*
** These are the allowed values for Mode.eMode.  There is a lot of overlap
** between these values and the Mode.spec.eStyle values, but they are not
** one-to-one, and thus need to be tracked separately.
*/
#define MODE_Ascii     0  /* Use ASCII unit and record separators (0x1F/0x1E) */
#define MODE_Box       1  /* Unicode box-drawing characters */
#define MODE_C         2  /* Comma-separated list of C-strings */
#define MODE_Column    3  /* One record per line in neat columns */
#define MODE_Count     4  /* Output only a count of the rows of output */
#define MODE_Csv       5  /* Quote strings, numbers are plain */
#define MODE_Html      6  /* Generate an XHTML table */
#define MODE_Insert    7  /* Generate SQL "insert" statements */
#define MODE_JAtom     8  /* Comma-separated list of JSON atoms */
#define MODE_JObject   9  /* One JSON object per row */
#define MODE_Json     10  /* Output JSON */
#define MODE_Line     11  /* One column per line.  Blank line between records */
#define MODE_List     12  /* One record per line with a separator */
#define MODE_Markdown 13  /* Markdown formatting */
#define MODE_Off      14  /* No query output shown */
#define MODE_Psql     15  /* Similar to psql */
#define MODE_QBox     16  /* BOX with SQL-quoted content */
#define MODE_Quote    17  /* Quote values as for SQL */
#define MODE_Split    18  /* Split-column mode */
#define MODE_Table    19  /* MySQL-style table formatting */
#define MODE_Tabs     20  /* Tab-separated values */
#define MODE_Tcl      21  /* Space-separated list of TCL strings */
#define MODE_Www      22  /* Full web-page output */

#define MODE_BUILTIN  22  /* Maximum built-in mode */
#define MODE_BATCH    50  /* Default mode for batch processing */
#define MODE_TTY      51  /* Default mode for interactive processing */
#define MODE_USER     75  /* First user-defined mode */
#define MODE_N_USER   25  /* Maximum number of user-defined modes */

/*
** Information about built-in display modes
*/
typedef struct ModeInfo ModeInfo;
struct ModeInfo {
  char zName[9];         /* Symbolic name of the mode */
  unsigned char eCSep;   /* Column separator */
  unsigned char eRSep;   /* Row separator */
  unsigned char eNull;   /* Null representation */
  unsigned char eText;   /* Default text encoding */
  unsigned char eHdr;    /* Default header encoding. */
  unsigned char eBlob;   /* Default blob encoding. */
  unsigned char bHdr;    /* Show headers by default.  0: n/a, 1: no 2: yes */
  unsigned char eStyle;  /* Underlying QRF style */
  unsigned char eCx;     /* 0: other, 1: line, 2: columnar */
  unsigned char mFlg;    /* Flags. 1=border-off 2=split-column */
};

/* String constants used by built-in modes */
static const char *aModeStr[] = 
  /* 0    1       2       3       4     5        6        7        8    */
   { 0,   "\n",   "|",    " ",    ",",  "\r\n",  "\036",  "\037",  "\t",
     "",  "NULL", "null", "\"\"", ": ",                                   };
  /* 9    10      11      12      13                                    */

static const ModeInfo aModeInfo[] = {
/*   zName      eCSep  eRSep eNull eText eHdr eBlob bHdr eStyle eCx mFlg */
  { "ascii",    7,     6,    9,    1,    1,    0,   1,   12,    0,  0 },
  { "box",      0,     0,    9,    1,    1,    0,   2,   1,     2,  0 },
  { "c",        4,     1,    10,   5,    5,    4,   1,   12,    0,  0 },
  { "column",   0,     0,    9,    1,    1,    0,   2,   2,     2,  0 },
  { "count",    0,     0,    0,    0,    0,    0,   0,   3,     0,  0 },
  { "csv",      4,     5,    9,    3,    3,    0,   1,   12,    0,  0 },
  { "html",     0,     0,    9,    4,    4,    0,   2,   7,     0,  0 },
  { "insert",   0,     0,    10,   2,    2,    0,   1,   8,     0,  0 },
  { "jatom",    4,     1,    11,   6,    6,    0,   1,   12,    0,  0 },
  { "jobject",  0,     1,    11,   6,    6,    0,   0,   10,    0,  0 },
  { "json",     0,     0,    11,   6,    6,    0,   0,   9,     0,  0 },
  { "line",     13,    1,    9,    1,    1,    0,   0,   11,    1,  0 },
  { "list",     2,     1,    9,    1,    1,    0,   1,   12,    0,  0 },
  { "markdown", 0,     0,    9,    1,    1,    0,   2,   13,    2,  0 },
  { "off",      0,     0,    0,    0,    0,    0,   0,   14,    0,  0 },
  { "psql",     0,     0,    9,    1,    1,    0,   2,   19,    2,  1 },
  { "qbox",     0,     0,    10,   2,    1,    0,   2,   1,     2,  0 },
  { "quote",    4,     1,    10,   2,    2,    0,   1,   12,    0,  0 },
  { "split",    0,     0,    9,    1,    1,    0,   1,   2,     2,  2 },
  { "table",    0,     0,    9,    1,    1,    0,   2,   19,    2,  0 },
  { "tabs",     8,     1,    9,    3,    3,    0,   1,   12,    0,  0 },
  { "tcl",      3,     1,    12,   5,    5,    4,   1,   12,    0,  0 },
  { "www",      0,     0,    9,    4,    4,    0,   2,   7,     0,  0 }
};     /*       |     /     /      |     /    /     |    |       \
       **       |    /     /       |    /    /      |    |        \_ 2: columnar
       ** Index into aModeStr[]    |   /    /       |    |           1: line
       **                          |  /    /        |    |           0: other
       **                          | /    /         |     \
       **           text encoding  |/     |    show |      \
       **      v-------------------'      |   hdrs? |       The QRF style
       **      0: n/a                blob |   v-----'
       **      1: plain        v_---------'   0: n/a
       **      2: sql          0: auto        1: no         
       **      3: csv          1: as-text     2: yes
       **      4: html         2: sql
       **      5: c            3: hex
       **      6: json         4: c
       **                      5: json
       **                      6: size
       ******************************************************************/
/*
** These are the column/row/line separators used by the various
** import/export modes.
*/
#define SEP_Column    "|"
#define SEP_Row       "\n"
#define SEP_Tab       "\t"
#define SEP_Space     " "
#define SEP_Comma     ","
#define SEP_CrLf      "\r\n"
#define SEP_Unit      "\x1F"
#define SEP_Record    "\x1E"

/*
** Default values for the various QRF limits
*/
#ifndef DFLT_CHAR_LIMIT
# define DFLT_CHAR_LIMIT  300
#endif
#ifndef DFLT_LINE_LIMIT
# define DFLT_LINE_LIMIT  5
#endif
#ifndef DFLT_TITLE_LIMIT
# define DFLT_TITLE_LIMIT 20
#endif
#ifndef DFLT_MULTI_INSERT
# define DFLT_MULTI_INSERT 3000
#endif

/*
** If the following flag is set, then command execution stops
** at an error if we are not interactive.
*/
static int bail_on_error = 0;

/*
** Treat stdin as an interactive input if the following variable
** is true.  Otherwise, assume stdin is connected to a file or pipe.
*/
static int stdin_is_interactive = 1;

/*
** Treat stdout like a TTY if true.
*/
static int stdout_is_console = 1;

/*
** Use this value as the width of the output device.  Or, figure it
** out at runtime if the value is negative.  Or use a default width
** if this value is zero.
*/
static int stdout_tty_width = -1;

/*
** The following is the open SQLite database.  We make a pointer
** to this database a static variable so that it can be accessed
** by the SIGINT handler to interrupt database processing.
*/
static sqlite3 *globalDb = 0;

/*
** True if an interrupt (Control-C) has been received.
*/
static volatile int seenInterrupt = 0;

/*
** This is the name of our program. It is set in main(), used
** in a number of other places, mostly for error messages.
*/
static char *Argv0;

/*
** Prompt strings. Initialized in main. Settable with
**   .prompt main continue
*/
#define PROMPT_LEN_MAX 128
/* First line prompt.   default: "sqlite> " */
static char mainPrompt[PROMPT_LEN_MAX];
/* Continuation prompt. default: "   ...> " */
static char continuePrompt[PROMPT_LEN_MAX];

/*
** Write I/O traces to the following stream.
*/
#ifdef SQLITE_ENABLE_IOTRACE
static FILE *iotrace = 0;
#endif

/*
** Output routines that are able to redirect to memory rather than
** doing actually I/O.
**                                                Works like.
**                                                --------------
**   cli_printf(FILE*, const char*, ...);         fprintf()
**   cli_puts(const char*, FILE*);                fputs()
**   cli_vprintf(FILE*, const char*, va_list);    vfprintf()
**
** These are just thin wrappers with the following added semantics:
** If the file-scope variable cli_output_capture is not NULL, and
** if the FILE* argument is stdout or stderr, then rather than
** writing to stdout/stdout, append the text to the cli_output_capture
** variable.
**
** The cli_exit(int) routine works like exit() except that it
** first dumps any capture output to stdout.
*/
static sqlite3_str *cli_output_capture = 0; 
static int cli_printf(FILE *out, const char *zFormat, ...){
  va_list ap;
  int rc;
  va_start(ap,zFormat);
  if( cli_output_capture && (out==stdout || out==stderr) ){
    sqlite3_str_vappendf(cli_output_capture, zFormat, ap);
    rc = 1;
  }else{
    rc = sqlite3_vfprintf(out, zFormat, ap);
  }
  va_end(ap);
  return rc;
}
static int cli_puts(const char *zText, FILE *out){
  if( cli_output_capture && (out==stdout || out==stderr) ){
    sqlite3_str_appendall(cli_output_capture, zText);
    return 1;
  }
  return sqlite3_fputs(zText, out);
}
#if 0 /* Not currently used - available if we need it later */
static int cli_vprintf(FILE *out, const char *zFormat, va_list ap){
  if( cli_output_capture && (out==stdout || out==stderr) ){
    sqlite3_str_vappendf(cli_output_capture, zFormat, ap);
    return 1;
  }else{
    return sqlite3_vfprintf(out, zFormat, ap);
  }
}
#endif
static void cli_exit(int rc){
  if( cli_output_capture ){
    char *z = sqlite3_str_finish(cli_output_capture);
    sqlite3_fputs(z, stdout);
    fflush(stdout);
  }
  exit(rc);
}


#define eputz(z) cli_puts(z,stderr)
#define sputz(fp,z) cli_puts(z,fp)

/* A version of strcmp() that works with NULL values */
static int cli_strcmp(const char *a, const char *b){
  if( a==0 ) a = "";
  if( b==0 ) b = "";
  return strcmp(a,b);
}
static int cli_strncmp(const char *a, const char *b, size_t n){
  if( a==0 ) a = "";
  if( b==0 ) b = "";
  return strncmp(a,b,n);
}

/* Return the current wall-clock time in microseconds since the
** Unix epoch (1970-01-01T00:00:00Z)
*/
static sqlite3_int64 timeOfDay(void){
#if defined(_WIN64) && _WIN32_WINNT >= _WIN32_WINNT_WIN8
  sqlite3_uint64 t;
  FILETIME tm;
  GetSystemTimePreciseAsFileTime(&tm);
  t =  ((u64)tm.dwHighDateTime<<32) | (u64)tm.dwLowDateTime;
  t += 116444736000000000LL;
  t /= 10;
  return t;
#elif defined(_WIN32)
  static sqlite3_vfs *clockVfs = 0;
  sqlite3_int64 t;
  if( clockVfs==0 ) clockVfs = sqlite3_vfs_find(0);
  if( clockVfs==0 ) return 0;  /* Never actually happens */
  if( clockVfs->iVersion>=2 && clockVfs->xCurrentTimeInt64!=0 ){
    clockVfs->xCurrentTimeInt64(clockVfs, &t);
  }else{
    double r;
    clockVfs->xCurrentTime(clockVfs, &r);
    t = (sqlite3_int64)(r*86400000.0);
  }
  return t*1000;
#else
  struct timeval sNow;
  (void)gettimeofday(&sNow,0);
  return ((i64)sNow.tv_sec)*1000000 + sNow.tv_usec;
#endif
}



/* This is variant of the standard-library strncpy() routine with the
** one change that the destination string is always zero-terminated, even
** if there is no zero-terminator in the first n-1 characters of the source
** string.
*/
static char *shell_strncpy(char *dest, const char *src, size_t n){
  size_t i;
  for(i=0; i<n-1 && src[i]!=0; i++) dest[i] = src[i];
  dest[i] = 0;
  return dest;
}

/*
** strcpy() workalike to squelch an unwarranted link-time warning
** from OpenBSD.
*/
static void shell_strcpy(char *dest, const char *src){
  while( (*(dest++) = *(src++))!=0 ){}
}

/*
** Optionally disable dynamic continuation prompt.
** Unless disabled, the continuation prompt shows open SQL lexemes if any,
** or open parentheses level if non-zero, or continuation prompt as set.
** This facility interacts with the scanner and process_input() where the
** below 5 macros are used.
*/
#ifdef SQLITE_OMIT_DYNAPROMPT
# define CONTINUATION_PROMPT continuePrompt
# define CONTINUE_PROMPT_RESET
# define CONTINUE_PROMPT_AWAITS(p,s)
# define CONTINUE_PROMPT_AWAITC(p,c)
# define CONTINUE_PAREN_INCR(p,n)
# define CONTINUE_PROMPT_PSTATE 0
typedef void *t_NoDynaPrompt;
# define SCAN_TRACKER_REFTYPE t_NoDynaPrompt
#else
# define CONTINUATION_PROMPT dynamicContinuePrompt()
# define CONTINUE_PROMPT_RESET \
  do {setLexemeOpen(&dynPrompt,0,0); trackParenLevel(&dynPrompt,0);} while(0)
# define CONTINUE_PROMPT_AWAITS(p,s) \
  if(p && stdin_is_interactive) setLexemeOpen(p, s, 0)
# define CONTINUE_PROMPT_AWAITC(p,c) \
  if(p && stdin_is_interactive) setLexemeOpen(p, 0, c)
# define CONTINUE_PAREN_INCR(p,n) \
  if(p && stdin_is_interactive) (trackParenLevel(p,n))
# define CONTINUE_PROMPT_PSTATE (&dynPrompt)
typedef struct DynaPrompt *t_DynaPromptRef;
# define SCAN_TRACKER_REFTYPE t_DynaPromptRef

static struct DynaPrompt {
  char dynamicPrompt[PROMPT_LEN_MAX];
  char acAwait[2];
  int inParenLevel;
  char *zScannerAwaits;
} dynPrompt = { {0}, {0}, 0, 0 };

/* Record parenthesis nesting level change, or force level to 0. */
static void trackParenLevel(struct DynaPrompt *p, int ni){
  p->inParenLevel += ni;
  if( ni==0 ) p->inParenLevel = 0;
  p->zScannerAwaits = 0;
}

/* Record that a lexeme is opened, or closed with args==0. */
static void setLexemeOpen(struct DynaPrompt *p, char *s, char c){
  if( s!=0 || c==0 ){
    p->zScannerAwaits = s;
    p->acAwait[0] = 0;
  }else{
    p->acAwait[0] = c;
    p->zScannerAwaits = p->acAwait;
  }
}

/* Upon demand, derive the continuation prompt to display. */
static char *dynamicContinuePrompt(void){
  if( continuePrompt[0]==0
      || (dynPrompt.zScannerAwaits==0 && dynPrompt.inParenLevel == 0) ){
    return continuePrompt;
  }else{
    if( dynPrompt.zScannerAwaits ){
      size_t ncp = strlen(continuePrompt);
      size_t ndp = strlen(dynPrompt.zScannerAwaits);
      if( ndp > ncp-3 ) return continuePrompt;
      shell_strcpy(dynPrompt.dynamicPrompt, dynPrompt.zScannerAwaits);
      while( ndp<3 ) dynPrompt.dynamicPrompt[ndp++] = ' ';
      shell_strncpy(dynPrompt.dynamicPrompt+3, continuePrompt+3,
              PROMPT_LEN_MAX-4);
    }else{
      if( dynPrompt.inParenLevel>9 ){
        shell_strncpy(dynPrompt.dynamicPrompt, "(..", 4);
      }else if( dynPrompt.inParenLevel<0 ){
        shell_strncpy(dynPrompt.dynamicPrompt, ")x!", 4);
      }else{
        shell_strncpy(dynPrompt.dynamicPrompt, "(x.", 4);
        dynPrompt.dynamicPrompt[2] = (char)('0'+dynPrompt.inParenLevel);
      }
      shell_strncpy(dynPrompt.dynamicPrompt+3, continuePrompt+3,
                    PROMPT_LEN_MAX-4);
    }
  }
  return dynPrompt.dynamicPrompt;
}
#endif /* !defined(SQLITE_OMIT_DYNAPROMPT) */

/* Indicate out-of-memory and exit. */
static void shell_out_of_memory(void){
  eputz("Error: out of memory\n");
  cli_exit(1);
}

/* Check a pointer to see if it is NULL.  If it is NULL, exit with an
** out-of-memory error.
*/
static void shell_check_oom(const void *p){
  if( p==0 ) shell_out_of_memory();
}

/*
** This routine works like printf in that its first argument is a
** format string and subsequent arguments are values to be substituted
** in place of % fields.  The result of formatting this string
** is written to iotrace.
*/
#ifdef SQLITE_ENABLE_IOTRACE
static void SQLITE_CDECL iotracePrintf(const char *zFormat, ...){
  va_list ap;
  char *z;
  if( iotrace==0 ) return;
  va_start(ap, zFormat);
  z = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
  cli_printf(iotrace, "%s", z);
  sqlite3_free(z);
}
#endif

/*
** Compute a string length that is limited to what can be stored in
** lower 30 bits of a 32-bit signed integer.
*/
static int strlen30(const char *z){
  size_t n;
  if( z==0 ) return 0;
  n = strlen(z);
  return n>0x3fffffff ? 0x3fffffff : (int)n;
}

/*
** Return open FILE * if zFile exists, can be opened for read
** and is an ordinary file or a character stream source.
** Otherwise return 0.
*/
static FILE * openChrSource(const char *zFile){
#if defined(_WIN32) || defined(WIN32)
  struct __stat64 x = {0};
# define STAT_CHR_SRC(mode) ((mode & (_S_IFCHR|_S_IFIFO|_S_IFREG))!=0)
  /* On Windows, open first, then check the stream nature. This order
  ** is necessary because _stat() and sibs, when checking a named pipe,
  ** effectively break the pipe as its supplier sees it. */
  FILE *rv = sqlite3_fopen(zFile, "rb");
  if( rv==0 ) return 0;
  if( _fstat64(_fileno(rv), &x) != 0
      || !STAT_CHR_SRC(x.st_mode)){
    fclose(rv);
    rv = 0;
  }
  return rv;
#else
  struct stat x = {0};
  int rc = stat(zFile, &x);
# define STAT_CHR_SRC(mode) (S_ISREG(mode)||S_ISFIFO(mode)||S_ISCHR(mode))
  if( rc!=0 ) return 0;
  if( STAT_CHR_SRC(x.st_mode) ){
    return sqlite3_fopen(zFile, "rb");
  }else{
    return 0;
  }
#endif
#undef STAT_CHR_SRC
}

/*
** This routine reads a line of text from FILE in, stores
** the text in memory obtained from malloc() and returns a pointer
** to the text.  NULL is returned at end of file, or if malloc()
** fails, or if the length of the line is longer than about a gigabyte.
**
** If zLine is not NULL then it is a malloced buffer returned from
** a previous call to this routine that may be reused.
*/
static char *local_getline(char *zLine, FILE *in){
  int nLine = zLine==0 ? 0 : 100;
  int n = 0;

  while( 1 ){
    if( n+100>nLine ){
      if( nLine>=1073741773 ){
        free(zLine);
        return 0;
      }
      nLine = nLine*2 + 100;
      zLine = realloc(zLine, nLine);
      shell_check_oom(zLine);
    }
    if( sqlite3_fgets(&zLine[n], nLine - n, in)==0 ){
      if( n==0 ){
        free(zLine);
        return 0;
      }
      zLine[n] = 0;
      break;
    }
    while( zLine[n] ) n++;
    if( n>0 && zLine[n-1]=='\n' ){
      n--;
      if( n>0 && zLine[n-1]=='\r' ) n--;
      zLine[n] = 0;
      break;
    }
  }
  return zLine;
}

/*
** Retrieve a single line of input text.
**
** If in==0 then read from standard input and prompt before each line.
** If isContinuation is true, then a continuation prompt is appropriate.
** If isContinuation is zero, then the main prompt should be used.
**
** If zPrior is not NULL then it is a buffer from a prior call to this
** routine that can be reused.
**
** The result is stored in space obtained from malloc() and must either
** be freed by the caller or else passed back into this routine via the
** zPrior argument for reuse.
*/
#ifndef SQLITE_SHELL_FIDDLE
static char *one_input_line(ShellState *p, char *zPrior, int isContinuation){
  char *zPrompt;
  char *zResult;
  FILE *in = p->in;
  if( in!=0 ){
    zResult = local_getline(zPrior, in);
  }else{
    zPrompt = isContinuation ? CONTINUATION_PROMPT : mainPrompt;
#if SHELL_USE_LOCAL_GETLINE
    sputz(stdout, zPrompt);
    fflush(stdout);
    do{
      zResult = local_getline(zPrior, stdin);
      zPrior = 0;
      /* ^C trap creates a false EOF, so let "interrupt" thread catch up. */
      if( zResult==0 ) sqlite3_sleep(50);
    }while( zResult==0 && seenInterrupt>0 );
#else
    free(zPrior);
    zResult = shell_readline(zPrompt);
    while( zResult==0 ){
      /* ^C trap creates a false EOF, so let "interrupt" thread catch up. */
      sqlite3_sleep(50);
      if( seenInterrupt==0 ) break;
      zResult = shell_readline("");
    }
    if( zResult && *zResult ) shell_add_history(zResult);
#endif
  }
  return zResult;
}
#endif /* !SQLITE_SHELL_FIDDLE */

/*
** Return the value of a hexadecimal digit.  Return -1 if the input
** is not a hex digit.
*/
static int hexDigitValue(char c){
  if( c>='0' && c<='9' ) return c - '0';
  if( c>='a' && c<='f' ) return c - 'a' + 10;
  if( c>='A' && c<='F' ) return c - 'A' + 10;
  return -1;
}

/*
** Interpret zArg as an integer value, possibly with suffixes.
**
** If the value specified by zArg is outside the range of values that
** can be represented using a 64-bit twos-complement integer, then return
** the nearest representable value.
*/
static sqlite3_int64 integerValue(const char *zArg){
  sqlite3_uint64 v = 0;
  static const struct { char *zSuffix; unsigned int iMult; } aMult[] = {
    { "KiB", 1024 },
    { "MiB", 1024*1024 },
    { "GiB", 1024*1024*1024 },
    { "KB",  1000 },
    { "MB",  1000000 },
    { "GB",  1000000000 },
    { "K",   1000 },
    { "M",   1000000 },
    { "G",   1000000000 },
  };
  int i;
  int isNeg = 0;
  if( zArg[0]=='-' ){
    isNeg = 1;
    zArg++;
  }else if( zArg[0]=='+' ){
    zArg++;
  }
  if( zArg[0]=='0' && zArg[1]=='x' ){
    int x;
    zArg += 2;
    while( (x = hexDigitValue(zArg[0]))>=0 ){
      if( v > 0x0fffffffffffffffULL ) goto integer_overflow;
      v = (v<<4) + x;
      zArg++;
    }
  }else{
    while( IsDigit(zArg[0]) ){
      if( v>=922337203685477580LL ){
        if( v>922337203685477580LL || zArg[0]>='8' ) goto integer_overflow;
      }
      v = v*10 + (zArg[0] - '0');
      zArg++;
    }
  }
  for(i=0; i<ArraySize(aMult); i++){
    if( sqlite3_stricmp(aMult[i].zSuffix, zArg)==0 ){
      if( 0x7fffffffffffffffULL/aMult[i].iMult < v ) goto integer_overflow;
      v *= aMult[i].iMult;
      break;
    }
  }
  if( isNeg && v>0x7fffffffffffffffULL ) goto integer_overflow;
  return isNeg? -(sqlite3_int64)v : (sqlite3_int64)v;
integer_overflow:
  return isNeg ? (i64)0x8000000000000000LL : 0x7fffffffffffffffLL;
}

/*
** A variable length string to which one can append text.
*/
typedef struct ShellText ShellText;
struct ShellText {
  char *zTxt;       /* The text */
  i64 n;            /* Number of bytes of zTxt[] actually used */
  i64 nAlloc;       /* Number of bytes allocated for zTxt[] */
};

/*
** Initialize and destroy a ShellText object
*/
static void initText(ShellText *p){
  memset(p, 0, sizeof(*p));
}
static void freeText(ShellText *p){
  sqlite3_free(p->zTxt);
  initText(p);
}

/* zIn is either a pointer to a NULL-terminated string in memory obtained
** from malloc(), or a NULL pointer. The string pointed to by zAppend is
** added to zIn, and the result returned in memory obtained from malloc().
** zIn, if it was not NULL, is freed.
**
** If the third argument, quote, is not '\0', then it is used as a
** quote character for zAppend.
*/
static void appendText(ShellText *p, const char *zAppend, char quote){
  i64 len;
  i64 i;
  i64 nAppend = strlen30(zAppend);

  len = nAppend+p->n+1;
  if( quote ){
    len += 2;
    for(i=0; i<nAppend; i++){
      if( zAppend[i]==quote ) len++;
    }
  }

  if( p->zTxt==0 || p->n+len>=p->nAlloc ){
    p->nAlloc = p->nAlloc*2 + len + 20;
    p->zTxt = sqlite3_realloc64(p->zTxt, p->nAlloc);
    shell_check_oom(p->zTxt);
  }

  if( quote ){
    char *zCsr = p->zTxt+p->n;
    *zCsr++ = quote;
    for(i=0; i<nAppend; i++){
      *zCsr++ = zAppend[i];
      if( zAppend[i]==quote ) *zCsr++ = quote;
    }
    *zCsr++ = quote;
    p->n = (i64)(zCsr - p->zTxt);
    *zCsr = '\0';
  }else{
    memcpy(p->zTxt+p->n, zAppend, nAppend);
    p->n += nAppend;
    p->zTxt[p->n] = '\0';
  }
}

/*
** Attempt to determine if identifier zName needs to be quoted, either
** because it contains non-alphanumeric characters, or because it is an
** SQLite keyword.  Be conservative in this estimate:  When in doubt assume
** that quoting is required.
**
** Return '"' if quoting is required.  Return 0 if no quoting is required.
*/
static char quoteChar(const char *zName){
  int i;
  if( zName==0 ) return '"';
  if( !IsAlpha(zName[0]) && zName[0]!='_' ) return '"';
  for(i=0; zName[i]; i++){
    if( !IsAlnum(zName[i]) && zName[i]!='_' ) return '"';
  }
  return sqlite3_keyword_check(zName, i) ? '"' : 0;
}

/*
** Construct a fake object name and column list to describe the structure
** of the view, virtual table, or table valued function zSchema.zName.
**
** The returned string comes from sqlite3_mprintf() and should be freed
** by the caller using sqlite3_free().
*/
static char *shellFakeSchema(
  sqlite3 *db,            /* The database connection containing the vtab */
  const char *zSchema,    /* Schema of the database holding the vtab */
  const char *zName       /* The name of the virtual table */
){
  sqlite3_stmt *pStmt = 0;
  char *zSql;
  ShellText s;
  char cQuote;
  char *zDiv = "(";
  int nRow = 0;

  zSql = sqlite3_mprintf("PRAGMA \"%w\".table_info=%Q;",
                         zSchema ? zSchema : "main", zName);
  shell_check_oom(zSql);
  sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  initText(&s);
  if( zSchema ){
    cQuote = quoteChar(zSchema);
    if( cQuote && sqlite3_stricmp(zSchema,"temp")==0 ) cQuote = 0;
    appendText(&s, zSchema, cQuote);
    appendText(&s, ".", 0);
  }
  cQuote = quoteChar(zName);
  appendText(&s, zName, cQuote);
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *zCol = (const char*)sqlite3_column_text(pStmt, 1);
    nRow++;
    appendText(&s, zDiv, 0);
    zDiv = ",";
    if( zCol==0 ) zCol = "";
    cQuote = quoteChar(zCol);
    appendText(&s, zCol, cQuote);
  }
  appendText(&s, ")", 0);
  sqlite3_finalize(pStmt);
  if( nRow==0 ){
    freeText(&s);
    s.zTxt = 0;
  }
  return s.zTxt;
}

/*
** SQL function:  strtod(X)
**
** Use the C-library strtod() function to convert string X into a double.
** Used for comparing the accuracy of SQLite's internal text-to-float conversion
** routines against the C-library.
*/
static void shellStrtod(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  char *z = (char*)sqlite3_value_text(apVal[0]);
  UNUSED_PARAMETER(nVal);
  if( z==0 ) return;
  sqlite3_result_double(pCtx, strtod(z,0));
}

/*
** SQL function:  dtostr(X)
**
** Use the C-library printf() function to convert real value X into a string.
** Used for comparing the accuracy of SQLite's internal float-to-text conversion
** routines against the C-library.
*/
static void shellDtostr(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  double r = sqlite3_value_double(apVal[0]);
  int n = nVal>=2 ? sqlite3_value_int(apVal[1]) : 26;
  char z[400];
  if( n<1 ) n = 1;
  if( n>350 ) n = 350;
  sprintf(z, "%#+.*e", n, r);
  sqlite3_result_text(pCtx, z, -1, SQLITE_TRANSIENT);
}

/*
** SQL function:  shell_add_schema(S,X)
**
** Add the schema name X to the CREATE statement in S and return the result.
** Examples:
**
**    CREATE TABLE t1(x)   ->   CREATE TABLE xyz.t1(x);
**
** Also works on
**
**    CREATE INDEX
**    CREATE UNIQUE INDEX
**    CREATE VIEW
**    CREATE TRIGGER
**    CREATE VIRTUAL TABLE
**
** This UDF is used by the .schema command to insert the schema name of
** attached databases into the middle of the sqlite_schema.sql field.
*/
static void shellAddSchemaName(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  static const char *aPrefix[] = {
     "TABLE",
     "INDEX",
     "UNIQUE INDEX",
     "VIEW",
     "TRIGGER",
     "VIRTUAL TABLE"
  };
  int i = 0;
  const char *zIn = (const char*)sqlite3_value_text(apVal[0]);
  const char *zSchema = (const char*)sqlite3_value_text(apVal[1]);
  const char *zName = (const char*)sqlite3_value_text(apVal[2]);
  sqlite3 *db = sqlite3_context_db_handle(pCtx);
  UNUSED_PARAMETER(nVal);
  if( zIn!=0 && cli_strncmp(zIn, "CREATE ", 7)==0 ){
    for(i=0; i<ArraySize(aPrefix); i++){
      int n = strlen30(aPrefix[i]);
      if( cli_strncmp(zIn+7, aPrefix[i], n)==0 && zIn[n+7]==' ' ){
        char *z = 0;
        char *zFake = 0;
        if( zSchema ){
          char cQuote = quoteChar(zSchema);
          if( cQuote && sqlite3_stricmp(zSchema,"temp")!=0 ){
            z = sqlite3_mprintf("%.*s \"%w\".%s", n+7, zIn, zSchema, zIn+n+8);
          }else{
            z = sqlite3_mprintf("%.*s %s.%s", n+7, zIn, zSchema, zIn+n+8);
          }
        }
        if( zName
         && aPrefix[i][0]=='V'
         && (zFake = shellFakeSchema(db, zSchema, zName))!=0
        ){
          if( z==0 ){
            z = sqlite3_mprintf("%s\n/* %s */", zIn, zFake);
          }else{
            z = sqlite3_mprintf("%z\n/* %s */", z, zFake);
          }
          sqlite3_free(zFake);
        }
        if( z ){
          sqlite3_result_text(pCtx, z, -1, sqlite3_free);
          return;
        }
      }
    }
  }
  sqlite3_result_value(pCtx, apVal[0]);
}


/************************* BEGIN PERFORMANCE TIMER *****************************/
#if !defined(_WIN32) && !defined(WIN32) && !defined(__minux)
#include <sys/time.h>
#include <sys/resource.h>
/* VxWorks does not support getrusage() as far as we can determine */
#if defined(_WRS_KERNEL) || defined(__RTP__)
struct rusage {
  struct timeval ru_utime; /* user CPU time used */
  struct timeval ru_stime; /* system CPU time used */
};
#define getrusage(A,B) memset(B,0,sizeof(*B))
#endif

/* Saved resource information for the beginning of an operation */
static struct rusage sBegin;  /* CPU time at start */
static sqlite3_int64 iBegin;  /* Wall-clock time at start */

/*
** Begin timing an operation
*/
static void beginTimer(ShellState *p){
  if( p->enableTimer || (p->flgProgress & SHELL_PROGRESS_TMOUT)!=0 ){
    getrusage(RUSAGE_SELF, &sBegin);
    iBegin = timeOfDay();
  }
}

/* Return the difference of two time_structs in seconds */
static double timeDiff(struct timeval *pStart, struct timeval *pEnd){
  return (pEnd->tv_usec - pStart->tv_usec)*0.000001 +
         (double)(pEnd->tv_sec - pStart->tv_sec);
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/* Return the time since the start of the timer in
** seconds. */
static double elapseTime(ShellState *NotUsed){
  (void)NotUsed;
  if( iBegin==0 ) return 0.0;
  return (timeOfDay() - iBegin)*0.000001;
}
#endif /* SQLITE_OMIT_PROGRESS_CALLBACK */

/*
** Print the timing results.
*/
static void endTimer(ShellState *p){
  if( p->enableTimer ){
    sqlite3_int64 iEnd = timeOfDay();
    struct rusage sEnd;
    getrusage(RUSAGE_SELF, &sEnd);
    p->prevTimer = (iEnd - iBegin)*0.000001;
    cli_printf(p->out, "Run Time: real %.6f user %.6f sys %.6f\n",
          p->prevTimer,
          timeDiff(&sBegin.ru_utime, &sEnd.ru_utime),
          timeDiff(&sBegin.ru_stime, &sEnd.ru_stime));
    if( p->enableTimer==1 ) p->enableTimer = 0;
    iBegin = 0;
  }
}

#define BEGIN_TIMER(X) beginTimer(X)
#define END_TIMER(X)   endTimer(X)
#define ELAPSE_TIME(X) elapseTime(X)
#define HAS_TIMER 1

#elif (defined(_WIN32) || defined(WIN32))

/* Saved resource information for the beginning of an operation */
static HANDLE hProcess;
static FILETIME ftKernelBegin;
static FILETIME ftUserBegin;
static sqlite3_int64 ftWallBegin;
typedef BOOL (WINAPI *GETPROCTIMES)(HANDLE, LPFILETIME, LPFILETIME,
                                    LPFILETIME, LPFILETIME);
static GETPROCTIMES getProcessTimesAddr = NULL;

/*
** Check to see if we have timer support.  Return 1 if necessary
** support found (or found previously).
*/
static int hasTimer(void){
  if( getProcessTimesAddr ){
    return 1;
  } else {
    /* GetProcessTimes() isn't supported in WIN95 and some other Windows
    ** versions. See if the version we are running on has it, and if it
    ** does, save off a pointer to it and the current process handle.
    */
    hProcess = GetCurrentProcess();
    if( hProcess ){
      HINSTANCE hinstLib = LoadLibrary(TEXT("Kernel32.dll"));
      if( NULL != hinstLib ){
        getProcessTimesAddr =
            (GETPROCTIMES) GetProcAddress(hinstLib, "GetProcessTimes");
        if( NULL != getProcessTimesAddr ){
          return 1;
        }
        FreeLibrary(hinstLib);
      }
    }
  }
  return 0;
}

/*
** Begin timing an operation
*/
static void beginTimer(ShellState *p){
  if( (p->enableTimer || (p->flgProgress & SHELL_PROGRESS_TMOUT)!=0)
   && getProcessTimesAddr
  ){
    FILETIME ftCreation, ftExit;
    getProcessTimesAddr(hProcess,&ftCreation,&ftExit,
                        &ftKernelBegin,&ftUserBegin);
    ftWallBegin = timeOfDay();
  }
}

/* Return the difference of two FILETIME structs in seconds */
static double timeDiff(FILETIME *pStart, FILETIME *pEnd){
  sqlite_int64 i64Start = *((sqlite_int64 *) pStart);
  sqlite_int64 i64End = *((sqlite_int64 *) pEnd);
  return (double) ((i64End - i64Start) / 10000000.0);
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/* Return the time since the start of the timer in
** seconds. */
static double elapseTime(ShellState *NotUsed){
  (void)NotUsed;
  if( ftWallBegin==0 ) return 0.0;
  return (timeOfDay() - ftWallBegin)*0.000001;
}
#endif /* SQLITE_OMIT_PROGRESS_CALLBACK */

/*
** Print the timing results.
*/
static void endTimer(ShellState *p){
  if( p->enableTimer && getProcessTimesAddr){
    FILETIME ftCreation, ftExit, ftKernelEnd, ftUserEnd;
    sqlite3_int64 ftWallEnd = timeOfDay();
    getProcessTimesAddr(hProcess,&ftCreation,&ftExit,&ftKernelEnd,&ftUserEnd);
    p->prevTimer = (ftWallEnd - ftWallBegin)*0.000001;
#ifdef _WIN64
    /* microsecond precision on 64-bit windows */
    cli_printf(p->out, "Run Time: real %.6f user %f sys %f\n",
          p->prevTimer,
          timeDiff(&ftUserBegin, &ftUserEnd),
          timeDiff(&ftKernelBegin, &ftKernelEnd));
#else
    /* millisecond precisino on 32-bit windows */
    cli_printf(p->out, "Run Time: real %.3f user %.3f sys %.3f\n",
          p->prevTimer,
          timeDiff(&ftUserBegin, &ftUserEnd),
          timeDiff(&ftKernelBegin, &ftKernelEnd));
#endif
    if( p->enableTimer==1 ) p->enableTimer = 0;
    ftWallBegin = 0;
  }
}

#define BEGIN_TIMER(X) beginTimer(X)
#define ELAPSE_TIME(X) elapseTime(X)
#define END_TIMER(X)   endTimer(X)
#define HAS_TIMER      hasTimer()

#else
#define BEGIN_TIMER(X) /* no-op */
#define ELAPSE_TIME(X) 0.0
#define END_TIMER(X)   /*no-op*/
#define HAS_TIMER 0
#endif
/************************* END PERFORMANCE TIMER ******************************/

/*
** Clear a display mode, freeing any allocated memory that it
** contains.
*/
static void modeFree(Mode *p){
  u8 autoExplain = p->autoExplain;
  free(p->spec.aWidth);
  free(p->spec.aAlign);
  free(p->spec.zColumnSep);
  free(p->spec.zRowSep);
  free(p->spec.zTableName);
  free(p->spec.zNull);
  memset(p, 0, sizeof(*p));
  p->spec.iVersion = 1;
  p->autoExplain = autoExplain;
}

/*
** Duplicate Mode pSrc into pDest.  pDest is assumed to be
** uninitialized prior to invoking this routine.
*/
static void modeDup(Mode *pDest, Mode *pSrc){
  memcpy(pDest, pSrc, sizeof(*pDest));
  if( pDest->spec.aWidth ){
    size_t sz = sizeof(pSrc->spec.aWidth[0]) * pSrc->spec.nWidth;
    pDest->spec.aWidth = malloc( sz );
    if( pDest->spec.aWidth ){
      memcpy(pDest->spec.aWidth, pSrc->spec.aWidth, sz);
    }else{
      pDest->spec.nWidth = 0;
    }
  }
  if( pDest->spec.aAlign ){
    size_t sz = sizeof(pSrc->spec.aAlign[0]) * pSrc->spec.nAlign;
    pDest->spec.aAlign = malloc( sz );
    if( pDest->spec.aAlign ){
      memcpy(pDest->spec.aAlign, pSrc->spec.aAlign, sz);
    }else{
      pDest->spec.nAlign = 0;
    }
  }
  if( pDest->spec.zColumnSep ){
    pDest->spec.zColumnSep = strdup(pSrc->spec.zColumnSep);
  }
  if( pDest->spec.zRowSep ){
    pDest->spec.zRowSep = strdup(pSrc->spec.zRowSep);
  }
  if( pDest->spec.zTableName ){
    pDest->spec.zTableName = strdup(pSrc->spec.zTableName);
  }
  if( pDest->spec.zNull ){
    pDest->spec.zNull = strdup(pSrc->spec.zNull);
  }
}

/*
** Set a string value to a copy of the zNew string in memory
** obtained from system malloc().
*/
static void modeSetStr(char **az, const char *zNew){
  free(*az);
  if( zNew==0 ){
    *az = 0;
  }else{
    size_t n = strlen(zNew);
    *az = malloc( n+1 );
    if( *az ){
      memcpy(*az, zNew, n+1 );
    }
  }
}

/*
** Change the mode to eMode
*/
static void modeChange(ShellState *p, unsigned char eMode){
  const ModeInfo *pI;
  if( eMode<ArraySize(aModeInfo) ){
    Mode *pM = &p->mode;
    pI = &aModeInfo[eMode];
    pM->eMode = eMode;
    if( pI->eCSep ) modeSetStr(&pM->spec.zColumnSep, aModeStr[pI->eCSep]);
    if( pI->eRSep ) modeSetStr(&pM->spec.zRowSep, aModeStr[pI->eRSep]);
    if( pI->eNull ) modeSetStr(&pM->spec.zNull, aModeStr[pI->eNull]);
    pM->spec.eText = pI->eText;
    pM->spec.eBlob = pI->eBlob;
    if( (pM->mFlags & MFLG_HDR)==0 ){
      pM->spec.bTitles = pI->bHdr;
    }
    pM->spec.eTitle = pI->eHdr;
    if( pI->mFlg & 0x01 ){
      pM->spec.bBorder = QRF_No;
    }else{
      pM->spec.bBorder = QRF_Auto;
    }
    if( pI->mFlg & 0x02 ){
      pM->spec.bSplitColumn = QRF_Yes;
      pM->bAutoScreenWidth = 1;
    }else{
      pM->spec.bSplitColumn = QRF_No;
    }
  }else if( eMode>=MODE_USER && eMode-MODE_USER<p->nSavedModes ){
    modeFree(&p->mode);
    modeDup(&p->mode, &p->aSavedModes[eMode-MODE_USER].mode);
  }else if( eMode==MODE_BATCH ){
    u8 mFlags = p->mode.mFlags;
    modeFree(&p->mode);
    modeChange(p, MODE_List);
    p->mode.mFlags = mFlags;
  }else if( eMode==MODE_TTY ){
    u8 mFlags = p->mode.mFlags;
    modeFree(&p->mode);
    modeChange(p, MODE_QBox);
    p->mode.bAutoScreenWidth = 1;
    p->mode.spec.eText = QRF_TEXT_Relaxed;
    p->mode.spec.nCharLimit = DFLT_CHAR_LIMIT;
    p->mode.spec.nLineLimit = DFLT_LINE_LIMIT;
    p->mode.spec.bTextJsonb = QRF_Yes;
    p->mode.spec.nTitleLimit = DFLT_TITLE_LIMIT;
    p->mode.spec.nMultiInsert = DFLT_MULTI_INSERT;
    p->mode.mFlags = mFlags;
  }
}

/*
** Set the mode to the default.  It assumed that the mode has
** already been freed and zeroed prior to calling this routine.
*/
static void modeDefault(ShellState *p){
  p->mode.spec.iVersion = 1;
  p->mode.autoExplain = 1;
  if( stdin_is_interactive || stdout_is_console ){
    modeChange(p, MODE_TTY);
  }else{
    modeChange(p, MODE_BATCH);
  }
}

/*
** Find the number of a display mode given its name.  Return -1 if
** the name does not match any mode.
**
** Saved modes are also searched if p!=NULL.  The number returned
** for a saved mode is the index into the p->aSavedModes[] array 
** plus MODE_USER.
**
** Two special mode names are also available: "batch" and "tty".
** evaluate to the default mode for batch operation and interactive
** operation on a TTY, respectively.
*/
static int modeFind(ShellState *p, const char *zName){
  int i;
  for(i=0; i<ArraySize(aModeInfo); i++){
    if( cli_strcmp(aModeInfo[i].zName,zName)==0 ) return i;
  }
  for(i=0; i<p->nSavedModes; i++){
    if( cli_strcmp(p->aSavedModes[i].zTag,zName)==0 ) return i+MODE_USER;
  }
  if( strcmp(zName,"batch")==0 ) return MODE_BATCH;
  if( strcmp(zName,"tty")==0 ) return MODE_TTY;
  return -1;
}

/*
** Save or restore the current output mode
*/
static void modePush(ShellState *p){
  if( p->nPopMode==0 ){
    modeFree(&p->modePrior);
    modeDup(&p->modePrior,&p->mode);
  }
}
static void modePop(ShellState *p){
  if( p->modePrior.spec.iVersion>0 ){
    modeFree(&p->mode);
    p->mode = p->modePrior;
    memset(&p->modePrior, 0, sizeof(p->modePrior));
  }
}


/*
** A callback for the sqlite3_log() interface.
*/
static void shellLog(void *pArg, int iErrCode, const char *zMsg){
  ShellState *p = (ShellState*)pArg;
  if( p->pLog==0 ) return;
  cli_printf(p->pLog, "(%d) %s\n", iErrCode, zMsg);
  fflush(p->pLog);
}

/*
** SQL function:  shell_putsnl(X)
**
** Write the text X to the screen (or whatever output is being directed)
** adding a newline at the end, and then return X.
*/
static void shellPutsFunc(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  ShellState *p = (ShellState*)sqlite3_user_data(pCtx);
  (void)nVal;
  cli_printf(p->out, "%s\n", sqlite3_value_text(apVal[0]));
  sqlite3_result_value(pCtx, apVal[0]);
}

/*
** Compute the name of the location of an input error in memory
** obtained from sqlite3_malloc().
*/
static char *shellErrorLocation(ShellState *p){
  char *zLoc;
  if( p->zErrPrefix ){
    zLoc = sqlite3_mprintf("%s", p->zErrPrefix);
  }else if( p->zInFile==0 || strcmp(p->zInFile,"<stdin>")==0){
    zLoc = sqlite3_mprintf("line %lld:", p->lineno);
  }else{
    zLoc = sqlite3_mprintf("%s:%lld:", p->zInFile, p->lineno);
  }
  return zLoc;
}

/*
** If in safe mode, print an error message described by the arguments
** and exit immediately.
*/
static void failIfSafeMode(
  ShellState *p,
  const char *zErrMsg,
  ...
){
  if( p->bSafeMode ){
    va_list ap;
    char *zMsg;
    char *zLoc = shellErrorLocation(p);
    va_start(ap, zErrMsg);
    zMsg = sqlite3_vmprintf(zErrMsg, ap);
    va_end(ap);
    cli_printf(stderr, "%s %s\n", zLoc, zMsg);
    cli_exit(1);
  }
}

/*
** Issue an error message from a dot-command.
*/
static void dotCmdError(
  ShellState *p,       /* Shell state */
  int iArg,            /* Index of argument on which error occurred */
  const char *zBrief,  /* Brief (<20 character) error description */
  const char *zDetail, /* Error details */
  ...
){
  FILE *out = stderr;
  char *zLoc = shellErrorLocation(p);
  if( zBrief!=0 && iArg>=0 && iArg<p->dot.nArg ){
    int i = p->dot.aiOfst[iArg];
    int nPrompt = strlen30(zBrief) + 5;
    cli_printf(out, "%s %s\n", zLoc, p->dot.zOrig);
    if( i > nPrompt ){
      cli_printf(out, "%s %*s%s ---^\n", zLoc, 1+i-nPrompt, "", zBrief);
    }else{
      cli_printf(out, "%s %*s^--- %s\n", zLoc, i, "", zBrief);
    }
  }
  if( zDetail ){
    char *zMsg;
    va_list ap;
    va_start(ap, zDetail);
    zMsg = sqlite3_vmprintf(zDetail,ap);
    va_end(ap);
    cli_printf(out,"%s %s\n", zLoc, zMsg);
    sqlite3_free(zMsg);
  }
  sqlite3_free(zLoc);
}
  

/*
** SQL function:   edit(VALUE)
**                 edit(VALUE,EDITOR)
**
** These steps:
**
**     (1) Write VALUE into a temporary file.
**     (2) Run program EDITOR on that temporary file.
**     (3) Read the temporary file back and return its content as the result.
**     (4) Delete the temporary file
**
** If the EDITOR argument is omitted, use the value in the VISUAL
** environment variable.  If still there is no EDITOR, through an error.
**
** Also throw an error if the EDITOR program returns a non-zero exit code.
*/
#ifndef SQLITE_NOHAVE_SYSTEM
static void editFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zEditor;
  char *zTempFile = 0;
  sqlite3 *db;
  char *zCmd = 0;
  int bBin;
  int rc;
  int hasCRLF = 0;
  FILE *f = 0;
  sqlite3_int64 sz;
  sqlite3_int64 x;
  unsigned char *p = 0;

  if( argc==2 ){
    zEditor = (const char*)sqlite3_value_text(argv[1]);
  }else{
    zEditor = getenv("VISUAL");
  }
  if( zEditor==0 ){
    sqlite3_result_error(context, "no editor for edit()", -1);
    return;
  }
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
    sqlite3_result_error(context, "NULL input to edit()", -1);
    return;
  }
  db = sqlite3_context_db_handle(context);
  zTempFile = 0;
  sqlite3_file_control(db, 0, SQLITE_FCNTL_TEMPFILENAME, &zTempFile);
  if( zTempFile==0 ){
    sqlite3_uint64 r = 0;
    sqlite3_randomness(sizeof(r), &r);
    zTempFile = sqlite3_mprintf("temp%llx", r);
    if( zTempFile==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  bBin = sqlite3_value_type(argv[0])==SQLITE_BLOB;
  /* When writing the file to be edited, do \n to \r\n conversions on systems
  ** that want \r\n line endings */
  f = sqlite3_fopen(zTempFile, bBin ? "wb" : "w");
  if( f==0 ){
    sqlite3_result_error(context, "edit() cannot open temp file", -1);
    goto edit_func_end;
  }
  sz = sqlite3_value_bytes(argv[0]);
  if( bBin ){
    x = fwrite(sqlite3_value_blob(argv[0]), 1, (size_t)sz, f);
  }else{
    const char *z = (const char*)sqlite3_value_text(argv[0]);
    /* Remember whether or not the value originally contained \r\n */
    if( z && strstr(z,"\r\n")!=0 ) hasCRLF = 1;
    x = fwrite(sqlite3_value_text(argv[0]), 1, (size_t)sz, f);
  }
  fclose(f);
  f = 0;
  if( x!=sz ){
    sqlite3_result_error(context, "edit() could not write the whole file", -1);
    goto edit_func_end;
  }
  zCmd = sqlite3_mprintf("%s \"%s\"", zEditor, zTempFile);
  if( zCmd==0 ){
    sqlite3_result_error_nomem(context);
    goto edit_func_end;
  }
  rc = system(zCmd);
  sqlite3_free(zCmd);
  if( rc ){
    sqlite3_result_error(context, "EDITOR returned non-zero", -1);
    goto edit_func_end;
  }
  f = sqlite3_fopen(zTempFile, "rb");
  if( f==0 ){
    sqlite3_result_error(context,
      "edit() cannot reopen temp file after edit", -1);
    goto edit_func_end;
  }
  fseek(f, 0, SEEK_END);
  sz = ftell(f);
  rewind(f);
  p = sqlite3_malloc64( sz+1 );
  if( p==0 ){
    sqlite3_result_error_nomem(context);
    goto edit_func_end;
  }
  x = fread(p, 1, (size_t)sz, f);
  fclose(f);
  f = 0;
  if( x!=sz ){
    sqlite3_result_error(context, "could not read back the whole file", -1);
    goto edit_func_end;
  }
  if( bBin ){
    sqlite3_result_blob64(context, p, sz, sqlite3_free);
  }else{
    sqlite3_int64 i, j;
    if( hasCRLF ){
      /* If the original contains \r\n then do no conversions back to \n */
    }else{
      /* If the file did not originally contain \r\n then convert any new
      ** \r\n back into \n */
      p[sz] = 0;
      for(i=j=0; i<sz; i++){
        if( p[i]=='\r' && p[i+1]=='\n' ) i++;
        p[j++] = p[i];
      }
      sz = j;
      p[sz] = 0;
    }
    sqlite3_result_text64(context, (const char*)p, sz,
                          sqlite3_free, SQLITE_UTF8);
  }
  p = 0;

edit_func_end:
  if( f ) fclose(f);
  unlink(zTempFile);
  sqlite3_free(zTempFile);
  sqlite3_free(p);
}
#endif /* SQLITE_NOHAVE_SYSTEM */

/*
** Set output mode to text or binary for Windows.
*/
static void setCrlfMode(ShellState *p){
#ifdef _WIN32
  if( p->mode.mFlags & MFLG_CRLF ){
    sqlite3_fsetmode(p->out, _O_TEXT);
  }else{
    sqlite3_fsetmode(p->out, _O_BINARY);
  }
#else
  UNUSED_PARAMETER(p);
#endif    
}

/*
** Find earliest of chars within s specified in zAny.
** With ns == ~0, is like strpbrk(s,zAny) and s must be 0-terminated.
*/
static const char *anyOfInStr(const char *s, const char *zAny, size_t ns){
  const char *pcFirst = 0;
  if( ns == ~(size_t)0 ) ns = strlen(s);
  while(*zAny){
    const char *pc = (const char*)memchr(s, *zAny&0xff, ns);
    if( pc ){
      pcFirst = pc;
      ns = pcFirst - s;
    }
    ++zAny;
  }
  return pcFirst;
}

/* Skip over as much z[] input char sequence as is valid UTF-8,
** limited per nAccept char's or whole characters and containing
** no char cn such that ((1<<cn) & ccm)!=0. On return, the
** sequence z:return (inclusive:exclusive) is validated UTF-8.
** Limit: nAccept>=0 => char count, nAccept<0 => character
 */
const char *zSkipValidUtf8(const char *z, int nAccept, long ccm){
  int ng = (nAccept<0)? -nAccept : 0;
  const char *pcLimit = (nAccept>=0)? z+nAccept : 0;
  assert(z!=0);
  while( (pcLimit)? (z<pcLimit) : (ng-- != 0) ){
    unsigned char c = *(u8*)z;
    if( c<0x7f ){
      if( ccm != 0L && c < 0x20 && ((1L<<c) & ccm) != 0 ) return z;
      ++z; /* ASCII */
    }else if( (c & 0xC0) != 0xC0 ) return z; /* not a lead byte */
    else{
      const char *zt = z+1; /* Got lead byte, look at trail bytes.*/
      do{
        if( pcLimit && zt >= pcLimit ) return z;
        else{
          char ct = *zt++;
          if( ct==0 || (zt-z)>4 || (ct & 0xC0)!=0x80 ){
            /* Trailing bytes are too few, too many, or invalid. */
            return z;
          }
        }
      } while( ((c <<= 1) & 0x40) == 0x40 ); /* Eat lead byte's count. */
      z = zt;
    }
  }
  return z;
}


/*
** Output the given string as a quoted according to C or TCL quoting rules.
*/
static void output_c_string(FILE *out, const char *z){
  char c;
  static const char *zq = "\"";
  static long ctrlMask = ~0L;
  static const char *zDQBSRO = "\"\\\x7f"; /* double-quote, backslash, rubout */
  char ace[3] = "\\?";
  char cbsSay;
  cli_puts(zq, out);
  if( z==0 ) z = "";
  while( *z!=0 ){
    const char *pcDQBSRO = anyOfInStr(z, zDQBSRO, ~(size_t)0);
    const char *pcPast = zSkipValidUtf8(z, INT_MAX, ctrlMask);
    const char *pcEnd = (pcDQBSRO && pcDQBSRO < pcPast)? pcDQBSRO : pcPast;
    if( pcEnd > z ){
      cli_printf(out, "%.*s", (int)(pcEnd-z), z);
    }
    if( (c = *pcEnd)==0 ) break;
    ++pcEnd;
    switch( c ){
    case '\\': case '"':
      cbsSay = (char)c;
      break;
    case '\t': cbsSay = 't'; break;
    case '\n': cbsSay = 'n'; break;
    case '\r': cbsSay = 'r'; break;
    case '\f': cbsSay = 'f'; break;
    default: cbsSay = 0; break;
    }
    if( cbsSay ){
      ace[1] = cbsSay;
      cli_puts(ace, out);
    }else if( !isprint(c&0xff) ){
      cli_printf(out, "\\%03o", c&0xff);
    }else{
      ace[1] = (char)c;
      cli_puts(ace+1, out);
    }
    z = pcEnd;
  }
  cli_puts(zq, out);
}

/* Encode input string z[] as a C-language string literal and
** append it to the sqlite3_str.  If z is NULL render and empty string.
*/
static void append_c_string(sqlite3_str *out, const char *z){
  char c;
  static const char *zq = "\"";
  static long ctrlMask = ~0L;
  static const char *zDQBSRO = "\"\\\x7f"; /* double-quote, backslash, rubout */
  char ace[3] = "\\?";
  char cbsSay;
  if( z==0 ) z = "";
  sqlite3_str_appendall(out,zq);
  while( *z!=0 ){
    const char *pcDQBSRO = anyOfInStr(z, zDQBSRO, ~(size_t)0);
    const char *pcPast = zSkipValidUtf8(z, INT_MAX, ctrlMask);
    const char *pcEnd = (pcDQBSRO && pcDQBSRO < pcPast)? pcDQBSRO : pcPast;
    if( pcEnd > z ){
      sqlite3_str_appendf(out, "%.*s", (int)(pcEnd-z), z);
    }
    if( (c = *pcEnd)==0 ) break;
    ++pcEnd;
    switch( c ){
    case '\\': case '"':
      cbsSay = (char)c;
      break;
    case '\t': cbsSay = 't'; break;
    case '\n': cbsSay = 'n'; break;
    case '\r': cbsSay = 'r'; break;
    case '\f': cbsSay = 'f'; break;
    default: cbsSay = 0; break;
    }
    if( cbsSay ){
      ace[1] = cbsSay;
      sqlite3_str_appendall(out,ace);
    }else if( !isprint(c&0xff) ){
      sqlite3_str_appendf(out, "\\%03o", c&0xff);
    }else{
      ace[1] = (char)c;
      sqlite3_str_appendall(out, ace+1);
    }
    z = pcEnd;
  }
  sqlite3_str_appendall(out, zq);
}

/*
** This routine runs when the user presses Ctrl-C
*/
static void interrupt_handler(int NotUsed){
  UNUSED_PARAMETER(NotUsed);
  if( ++seenInterrupt>1 ) cli_exit(1);
  if( globalDb ) sqlite3_interrupt(globalDb);
}

/* Try to determine the screen width.  Use the default if unable.
*/
int shellScreenWidth(void){
  if( stdout_tty_width>0 ){
    return stdout_tty_width;
  }else{
#if defined(TIOCGSIZE)
    struct ttysize ts;
    if( ioctl(STDIN_FILENO, TIOCGSIZE, &ts)>=0
     || ioctl(STDOUT_FILENO, TIOCGSIZE, &ts)>=0
     || ioctl(STDERR_FILENO, TIOCGSIZE, &ts)>=0
    ){
      return ts.ts_cols;
    }
#elif defined(TIOCGWINSZ)
    struct winsize ws;
    if( ioctl(STDIN_FILENO, TIOCGWINSZ, &ws)>=0
     || ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws)>=0
     || ioctl(STDERR_FILENO, TIOCGWINSZ, &ws)>=0
    ){
      return ws.ws_col;
    }
#elif defined(_WIN32)
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    if( GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi)
     || GetConsoleScreenBufferInfo(GetStdHandle(STD_ERROR_HANDLE), &csbi)
     || GetConsoleScreenBufferInfo(GetStdHandle(STD_INPUT_HANDLE), &csbi)
    ){
      return csbi.srWindow.Right - csbi.srWindow.Left + 1;
    }
#endif
#define DEFAULT_SCREEN_WIDTH 80
    return DEFAULT_SCREEN_WIDTH;
  }
}

#if (defined(_WIN32) || defined(WIN32)) && !defined(_WIN32_WCE)
/*
** This routine runs for console events (e.g. Ctrl-C) on Win32
*/
static BOOL WINAPI ConsoleCtrlHandler(
  DWORD dwCtrlType /* One of the CTRL_*_EVENT constants */
){
  if( dwCtrlType==CTRL_C_EVENT ){
    interrupt_handler(0);
    return TRUE;
  }
  return FALSE;
}
#endif

#ifndef SQLITE_OMIT_AUTHORIZATION
/*
** This authorizer runs in safe mode.
*/
static int safeModeAuth(
  void *pClientData,
  int op,
  const char *zA1,
  const char *zA2,
  const char *zA3,
  const char *zA4
){
  ShellState *p = (ShellState*)pClientData;
  static const char *azProhibitedFunctions[] = {
    "edit",
    "fts3_tokenizer",
    "load_extension",
    "readfile",
    "realpath",
    "writefile",
    "zipfile",
    "zipfile_cds",
  };
  UNUSED_PARAMETER(zA1);
  UNUSED_PARAMETER(zA3);
  UNUSED_PARAMETER(zA4);
  switch( op ){
    case SQLITE_ATTACH: {
#ifndef SQLITE_SHELL_FIDDLE
      /* In WASM builds the filesystem is a virtual sandbox, so
      ** there's no harm in using ATTACH. */
      failIfSafeMode(p, "cannot run ATTACH in safe mode");
#endif
      break;
    }
    case SQLITE_FUNCTION: {
      int i;
      for(i=0; i<ArraySize(azProhibitedFunctions); i++){
        if( sqlite3_stricmp(zA2, azProhibitedFunctions[i])==0 ){
          failIfSafeMode(p, "cannot use the %s() function in safe mode",
                         azProhibitedFunctions[i]);
        }
      }
      break;
    }
  }
  return SQLITE_OK;
}

/*
** When the ".auth ON" is set, the following authorizer callback is
** invoked.  It always returns SQLITE_OK.
*/
static int shellAuth(
  void *pClientData,
  int op,
  const char *zA1,
  const char *zA2,
  const char *zA3,
  const char *zA4
){
  ShellState *p = (ShellState*)pClientData;
  static const char *azAction[] = { 0,
     "CREATE_INDEX",         "CREATE_TABLE",         "CREATE_TEMP_INDEX",
     "CREATE_TEMP_TABLE",    "CREATE_TEMP_TRIGGER",  "CREATE_TEMP_VIEW",
     "CREATE_TRIGGER",       "CREATE_VIEW",          "DELETE",
     "DROP_INDEX",           "DROP_TABLE",           "DROP_TEMP_INDEX",
     "DROP_TEMP_TABLE",      "DROP_TEMP_TRIGGER",    "DROP_TEMP_VIEW",
     "DROP_TRIGGER",         "DROP_VIEW",            "INSERT",
     "PRAGMA",               "READ",                 "SELECT",
     "TRANSACTION",          "UPDATE",               "ATTACH",
     "DETACH",               "ALTER_TABLE",          "REINDEX",
     "ANALYZE",              "CREATE_VTABLE",        "DROP_VTABLE",
     "FUNCTION",             "SAVEPOINT",            "RECURSIVE"
  };
  int i;
  const char *az[4];
  az[0] = zA1;
  az[1] = zA2;
  az[2] = zA3;
  az[3] = zA4;
  cli_printf(p->out, "authorizer: %s", azAction[op]);
  for(i=0; i<4; i++){
    cli_puts(" ", p->out);
    if( az[i] ){
      output_c_string(p->out, az[i]);
    }else{
      cli_puts("NULL", p->out);
    }
  }
  cli_puts("\n", p->out);
  if( p->bSafeMode ) (void)safeModeAuth(pClientData, op, zA1, zA2, zA3, zA4);
  return SQLITE_OK;
}
#endif

/*
** Print a schema statement.  This is helper routine to dump_callbac().
**
** This routine converts some CREATE TABLE statements for shadow tables
** in FTS3/4/5 into CREATE TABLE IF NOT EXISTS statements.
**
** If the schema statement in z[] contains a start-of-comment and if
** sqlite3_complete() returns false, try to terminate the comment before
** printing the result.  https://sqlite.org/forum/forumpost/d7be961c5c
*/
static void printSchemaLine(FILE *out, const char *z, const char *zTail){
  char *zToFree = 0;
  if( z==0 ) return;
  if( zTail==0 ) return;
  if( zTail[0]==';' && (strstr(z, "/*")!=0 || strstr(z,"--")!=0) ){
    const char *zOrig = z;
    static const char *azTerm[] = { "", "*/", "\n" };
    int i;
    for(i=0; i<ArraySize(azTerm); i++){
      char *zNew = sqlite3_mprintf("%s%s;", zOrig, azTerm[i]);
      shell_check_oom(zNew);
      if( sqlite3_complete(zNew) ){
        size_t n = strlen(zNew);
        zNew[n-1] = 0;
        zToFree = zNew;
        z = zNew;
        break;
      }
      sqlite3_free(zNew);
    }
  }
  if( sqlite3_strglob("CREATE TABLE ['\"]*", z)==0 ){
    cli_printf(out, "CREATE TABLE IF NOT EXISTS %s%s", z+13, zTail);
  }else{
    cli_printf(out, "%s%s", z, zTail);
  }
  sqlite3_free(zToFree);
}

/*
** Return true if string z[] has nothing but whitespace and comments to the
** end of the first line.
*/
static int wsToEol(const char *z){
  int i;
  for(i=0; z[i]; i++){
    if( z[i]=='\n' ) return 1;
    if( IsSpace(z[i]) ) continue;
    if( z[i]=='-' && z[i+1]=='-' ) return 1;
    return 0;
  }
  return 1;
}

/*
** SQL Function:  shell_format_schema(SQL,FLAGS)
**
** This function is internally by the CLI to assist with the
** ".schema", ".fullschema", and ".dump" commands.  The first
** argument is the value from sqlite_schema.sql.  The value returned
** is a modification of the input that can actually be run as SQL
** to recreate the schema object.
**
** When FLAGS is zero, the only changes is to append ";".  If the
** 0x01 bit of FLAGS is set, then transformations are made to implement
** ".schema --indent".
*/
static void shellFormatSchema(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  int flags;          /* Value of 2nd parameter */
  const char *zSql;   /* Value of 1st parameter */
  int nSql;           /* Bytes of text in zSql[] */
  sqlite3_str *pOut;  /* Output buffer */
  char *z;            /* Writable copy of zSql */
  int i, j;           /* Loop counters */
  int nParen = 0;
  char cEnd = 0;
  char c;
  int nLine = 0;
  int isIndex;
  int isWhere = 0;

  assert( nVal==2 );
  pOut = sqlite3_str_new(sqlite3_context_db_handle(pCtx));
  nSql = sqlite3_value_bytes(apVal[0]);
  zSql = (const char*)sqlite3_value_text(apVal[0]);
  if( zSql==0 || zSql[0]==0 ) goto shellFormatSchema_finish;
  flags = sqlite3_value_int(apVal[1]);
  if( (flags & 0x01)==0 ){
    sqlite3_str_append(pOut, zSql, nSql);
    sqlite3_str_append(pOut, ";", 1);
    goto shellFormatSchema_finish;
  }
  if( sqlite3_strlike("CREATE VIEW%", zSql, 0)==0
   || sqlite3_strlike("CREATE TRIG%", zSql, 0)==0
  ){
    sqlite3_str_append(pOut, zSql, nSql);
    sqlite3_str_append(pOut, ";", 1);
    goto shellFormatSchema_finish;
  }
  isIndex = sqlite3_strlike("CREATE INDEX%", zSql, 0)==0
         || sqlite3_strlike("CREATE UNIQUE INDEX%", zSql, 0)==0;
  z = sqlite3_mprintf("%s", zSql);
  if( z==0 ){
    sqlite3_str_free(pOut);
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  j = 0;
  for(i=0; IsSpace(z[i]); i++){}
  for(; (c = z[i])!=0; i++){
    if( IsSpace(c) ){
      if( z[j-1]=='\r' ) z[j-1] = '\n';
      if( IsSpace(z[j-1]) || z[j-1]=='(' ) continue;
    }else if( (c=='(' || c==')') && j>0 && IsSpace(z[j-1]) ){
      j--;
    }
    z[j++] = c;
  }
  while( j>0 && IsSpace(z[j-1]) ){ j--; }
  z[j] = 0;
  if( strlen30(z)>=79 ){
    for(i=j=0; (c = z[i])!=0; i++){ /* Copy from z[i] back to z[j] */
      if( c==cEnd ){
        cEnd = 0;
      }else if( cEnd!=0){
        /* No-op */
      }else if( c=='"' || c=='\'' || c=='`' ){
        cEnd = c;
      }else if( c=='[' ){
        cEnd = ']';
      }else if( c=='-' && z[i+1]=='-' ){
        cEnd = '\n';
      }else if( c=='(' ){
        nParen++;
      }else if( c==')' ){
        nParen--;
        if( nLine>0 && nParen==0 && j>0 && !isWhere ){
          sqlite3_str_append(pOut, z, j);
          sqlite3_str_append(pOut, "\n", 1);
          j = 0;
        }
      }else if( (c=='w' || c=='W')
             && nParen==0 && isIndex
             && sqlite3_strnicmp("WHERE",&z[i],5)==0
             && !IsAlnum(z[i+5]) && z[i+5]!='_' ){
        isWhere = 1;
      }else if( isWhere && (c=='A' || c=='a')
             && nParen==0
             && sqlite3_strnicmp("AND",&z[i],3)==0
             && !IsAlnum(z[i+3]) && z[i+3]!='_' ){
        sqlite3_str_append(pOut, z, j);
        sqlite3_str_append(pOut, "\n    ", 5);
        j = 0;
      }
      z[j++] = c;
      if( nParen==1 && cEnd==0
       && (c=='(' || c=='\n' || (c==',' && !wsToEol(z+i+1)))
       && !isWhere
      ){
        if( c=='\n' ) j--;
        sqlite3_str_append(pOut, z, j);
        sqlite3_str_append(pOut, "\n  ", 3);
        j = 0;
        nLine++;
        while( IsSpace(z[i+1]) ){ i++; }
      }
    }
    z[j] = 0;
  }
  sqlite3_str_appendall(pOut, z);
  sqlite3_str_append(pOut, ";", 1);
  sqlite3_free(z);

shellFormatSchema_finish:
  sqlite3_result_text(pCtx, sqlite3_str_finish(pOut), -1, sqlite3_free);
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*
** Progress handler callback.
*/
static int progress_handler(void *pClientData) {
  ShellState *p = (ShellState*)pClientData;
  p->nProgress++;
  if( (p->flgProgress & SHELL_PROGRESS_TMOUT)!=0
   && ELAPSE_TIME(p)>=p->tmProgress
  ){
    cli_printf(p->out, "Progress timeout after %.6f seconds\n", 
               ELAPSE_TIME(p));
    return 1;
  }
  if( p->nProgress>=p->mxProgress && p->mxProgress>0 ){
    cli_printf(p->out, "Progress limit reached (%u)\n", p->nProgress);
    if( p->flgProgress & SHELL_PROGRESS_RESET ) p->nProgress = 0;
    if( p->flgProgress & SHELL_PROGRESS_ONCE ) p->mxProgress = 0;
    return 1;
  }
  if( (p->flgProgress & SHELL_PROGRESS_QUIET)==0 ){
    cli_printf(p->out, "Progress %u\n", p->nProgress);
  }
  return 0;
}
#endif /* SQLITE_OMIT_PROGRESS_CALLBACK */

/*
** This is the callback routine from sqlite3_exec() that appends all
** output onto the end of a ShellText object.
*/
static int captureOutputCallback(void *pArg, int nArg, char **azArg, char **az){
  ShellText *p = (ShellText*)pArg;
  int i;
  UNUSED_PARAMETER(az);
  if( azArg==0 ) return 0;
  if( p->n ) appendText(p, "|", 0);
  for(i=0; i<nArg; i++){
    if( i ) appendText(p, ",", 0);
    if( azArg[i] ) appendText(p, azArg[i], 0);
  }
  return 0;
}

/*
** Generate an appropriate SELFTEST table in the main database.
*/
static void createSelftestTable(ShellState *p){
  char *zErrMsg = 0;
  sqlite3_exec(p->db,
    "SAVEPOINT selftest_init;\n"
    "CREATE TABLE IF NOT EXISTS selftest(\n"
    "  tno INTEGER PRIMARY KEY,\n"   /* Test number */
    "  op TEXT,\n"                   /* Operator:  memo run */
    "  cmd TEXT,\n"                  /* Command text */
    "  ans TEXT\n"                   /* Desired answer */
    ");"
    "CREATE TEMP TABLE [_shell$self](op,cmd,ans);\n"
    "INSERT INTO [_shell$self](rowid,op,cmd)\n"
    "  VALUES(coalesce((SELECT (max(tno)+100)/10 FROM selftest),10),\n"
    "         'memo','Tests generated by --init');\n"
    "INSERT INTO [_shell$self]\n"
    "  SELECT 'run',\n"
    "    'SELECT hex(sha3_query(''SELECT type,name,tbl_name,sql "
                                 "FROM sqlite_schema ORDER BY 2'',224))',\n"
    "    hex(sha3_query('SELECT type,name,tbl_name,sql "
                          "FROM sqlite_schema ORDER BY 2',224));\n"
    "INSERT INTO [_shell$self]\n"
    "  SELECT 'run',"
    "    'SELECT hex(sha3_query(''SELECT * FROM \"' ||"
    "        printf('%w',name) || '\" NOT INDEXED'',224))',\n"
    "    hex(sha3_query(printf('SELECT * FROM \"%w\" NOT INDEXED',name),224))\n"
    "  FROM (\n"
    "    SELECT name FROM sqlite_schema\n"
    "     WHERE type='table'\n"
    "       AND name<>'selftest'\n"
    "       AND coalesce(rootpage,0)>0\n"
    "  )\n"
    " ORDER BY name;\n"
    "INSERT INTO [_shell$self]\n"
    "  VALUES('run','PRAGMA integrity_check','ok');\n"
    "INSERT INTO selftest(tno,op,cmd,ans)"
    "  SELECT rowid*10,op,cmd,ans FROM [_shell$self];\n"
    "DROP TABLE [_shell$self];"
    ,0,0,&zErrMsg);
  if( zErrMsg ){
    cli_printf(stderr, "SELFTEST initialization failure: %s\n", zErrMsg);
    sqlite3_free(zErrMsg);
  }
  sqlite3_exec(p->db, "RELEASE selftest_init",0,0,0);
}


/*
** Set the destination table field of the ShellState structure to
** the name of the table given.  Escape any quote characters in the
** table name.
*/
static void set_table_name(ShellState *p, const char *zName){
  if( p->zDestTable ){
    sqlite3_free(p->zDestTable);
    p->zDestTable = 0;
  }
  if( zName==0 ) return;
  p->zDestTable = sqlite3_mprintf("%s", zName);
  shell_check_oom(p->zDestTable);
}

/*
** Maybe construct two lines of text that point out the position of a
** syntax error.  Return a pointer to the text, in memory obtained from
** sqlite3_malloc().  Or, if the most recent error does not involve a
** specific token that we can point to, return an empty string.
**
** In all cases, the memory returned is obtained from sqlite3_malloc64()
** and should be released by the caller invoking sqlite3_free().
*/
static char *shell_error_context(const char *zSql, sqlite3 *db){
  int iOffset;
  size_t len;
  char *zCode;
  char *zMsg;
  int i;
  if( db==0
   || zSql==0
   || (iOffset = sqlite3_error_offset(db))<0
   || iOffset>=(int)strlen(zSql)
  ){
    return sqlite3_mprintf("");
  }
  while( iOffset>50 ){
    iOffset--;
    zSql++;
    while( (zSql[0]&0xc0)==0x80 ){ zSql++; iOffset--; }
  }
  len = strlen(zSql);
  if( len>78 ){
    len = 78;
    while( len>0 && (zSql[len]&0xc0)==0x80 ) len--;
  }
  zCode = sqlite3_mprintf("%.*s", len, zSql);
  shell_check_oom(zCode);
  for(i=0; zCode[i]; i++){ if( IsSpace(zSql[i]) ) zCode[i] = ' '; }
  if( iOffset<25 ){
    zMsg = sqlite3_mprintf("\n  %z\n  %*s^--- error here", zCode,iOffset,"");
  }else{
    zMsg = sqlite3_mprintf("\n  %z\n  %*serror here ---^", zCode,iOffset-14,"");
  }
  return zMsg;
}


/*
** Execute a query statement that will generate SQL output.  Print
** the result columns, comma-separated, on a line and then add a
** semicolon terminator to the end of that line.
**
** If the number of columns is 1 and that column contains text "--"
** then write the semicolon on a separate line.  That way, if a
** "--" comment occurs at the end of the statement, the comment
** won't consume the semicolon terminator.
*/
static int run_table_dump_query(
  ShellState *p,           /* Query context */
  const char *zSelect      /* SELECT statement to extract content */
){
  sqlite3_stmt *pSelect;
  int rc;
  int nResult;
  int i;
  const char *z;
  rc = sqlite3_prepare_v2(p->db, zSelect, -1, &pSelect, 0);
  if( rc!=SQLITE_OK || !pSelect ){
    char *zContext = shell_error_context(zSelect, p->db);
    cli_printf(p->out, "/**** ERROR: (%d) %s *****/\n%s",
          rc, sqlite3_errmsg(p->db), zContext);
    sqlite3_free(zContext);
    if( (rc&0xff)!=SQLITE_CORRUPT ) p->nErr++;
    return rc;
  }
  rc = sqlite3_step(pSelect);
  nResult = sqlite3_column_count(pSelect);
  while( rc==SQLITE_ROW ){
    z = (const char*)sqlite3_column_text(pSelect, 0);
    cli_printf(p->out, "%s", z);
    for(i=1; i<nResult; i++){
      cli_printf(p->out, ",%s", sqlite3_column_text(pSelect, i));
    }
    if( z==0 ) z = "";
    while( z[0] && (z[0]!='-' || z[1]!='-') ) z++;
    if( z[0] ){
      cli_puts("\n;\n", p->out);
    }else{
      cli_puts(";\n", p->out);
    }
    rc = sqlite3_step(pSelect);
  }
  rc = sqlite3_finalize(pSelect);
  if( rc!=SQLITE_OK ){
    cli_printf(p->out, "/**** ERROR: (%d) %s *****/\n",
                    rc, sqlite3_errmsg(p->db));
    if( (rc&0xff)!=SQLITE_CORRUPT ) p->nErr++;
  }
  return rc;
}

/*
** Allocate space and save off string indicating current error.
*/
static char *save_err_msg(
  sqlite3 *db,           /* Database to query */
  const char *zPhase,    /* When the error occurs */
  int rc,                /* Error code returned from API */
  const char *zSql       /* SQL string, or NULL */
){
  char *zErr;
  char *zContext;
  sqlite3_str *pStr = sqlite3_str_new(0);
  sqlite3_str_appendf(pStr, "%s, %s", zPhase, sqlite3_errmsg(db));
  if( rc>1 ){
    sqlite3_str_appendf(pStr, " (%d)", rc);
  }
  zContext = shell_error_context(zSql, db);
  if( zContext ){
    sqlite3_str_appendall(pStr, zContext);
    sqlite3_free(zContext);
  }
  zErr = sqlite3_str_finish(pStr);
  shell_check_oom(zErr);
  return zErr;
}

#ifdef __linux__
/*
** Attempt to display I/O stats on Linux using /proc/PID/io
*/
static void displayLinuxIoStats(FILE *out){
  FILE *in;
  char z[200];
  sqlite3_snprintf(sizeof(z), z, "/proc/%d/io", getpid());
  in = sqlite3_fopen(z, "rb");
  if( in==0 ) return;
  while( sqlite3_fgets(z, sizeof(z), in)!=0 ){
    static const struct {
      const char *zPattern;
      const char *zDesc;
    } aTrans[] = {
      { "rchar: ",                  "Bytes received by read():" },
      { "wchar: ",                  "Bytes sent to write():"    },
      { "syscr: ",                  "Read() system calls:"      },
      { "syscw: ",                  "Write() system calls:"     },
      { "read_bytes: ",             "Bytes read from storage:"  },
      { "write_bytes: ",            "Bytes written to storage:" },
      { "cancelled_write_bytes: ",  "Cancelled write bytes:"    },
    };
    int i;
    for(i=0; i<ArraySize(aTrans); i++){
      int n = strlen30(aTrans[i].zPattern);
      if( cli_strncmp(aTrans[i].zPattern, z, n)==0 ){
        cli_printf(out, "%-36s %s", aTrans[i].zDesc, &z[n]);
        break;
      }
    }
  }
  fclose(in);
}
#endif

/*
** Display a single line of status using 64-bit values.
*/
static void displayStatLine(
  FILE *out,                /* Write to this channel */
  char *zLabel,             /* Label for this one line */
  char *zFormat,            /* Format for the result */
  int iStatusCtrl,          /* Which status to display */
  int bReset                /* True to reset the stats */
){
  sqlite3_int64 iCur = -1;
  sqlite3_int64 iHiwtr = -1;
  int i, nPercent;
  char zLine[200];
  sqlite3_status64(iStatusCtrl, &iCur, &iHiwtr, bReset);
  for(i=0, nPercent=0; zFormat[i]; i++){
    if( zFormat[i]=='%' ) nPercent++;
  }
  if( nPercent>1 ){
    sqlite3_snprintf(sizeof(zLine), zLine, zFormat, iCur, iHiwtr);
  }else{
    sqlite3_snprintf(sizeof(zLine), zLine, zFormat, iHiwtr);
  }
  cli_printf(out, "%-36s %s\n", zLabel, zLine);
}

/*
** Display memory stats.
*/
static int display_stats(
  sqlite3 *db,                /* Database to query */
  ShellState *pArg,           /* Pointer to ShellState */
  int bReset                  /* True to reset the stats */
){
  int iCur, iHiwtr;
  sqlite3_int64 iCur64, iHiwtr64;
  FILE *out;
  if( pArg==0 || pArg->out==0 ) return 0;
  out = pArg->out;

  if( pArg->pStmt && pArg->statsOn==2 ){
    int nCol, i, x;
    sqlite3_stmt *pStmt = pArg->pStmt;
    char z[100];
    nCol = sqlite3_column_count(pStmt);
    cli_printf(out, "%-36s %d\n", "Number of output columns:", nCol);
    for(i=0; i<nCol; i++){
      sqlite3_snprintf(sizeof(z),z,"Column %d %nname:", i, &x);
      cli_printf(out, "%-36s %s\n", z, sqlite3_column_name(pStmt,i));
#ifndef SQLITE_OMIT_DECLTYPE
      sqlite3_snprintf(30, z+x, "declared type:");
      cli_printf(out, "%-36s %s\n", z, sqlite3_column_decltype(pStmt, i));
#endif
#ifdef SQLITE_ENABLE_COLUMN_METADATA
      sqlite3_snprintf(30, z+x, "database name:");
      cli_printf(out, "%-36s %s\n", z,
                           sqlite3_column_database_name(pStmt,i));
      sqlite3_snprintf(30, z+x, "table name:");
      cli_printf(out, "%-36s %s\n", z, sqlite3_column_table_name(pStmt,i));
      sqlite3_snprintf(30, z+x, "origin name:");
      cli_printf(out, "%-36s %s\n", z,sqlite3_column_origin_name(pStmt,i));
#endif
    }
  }

  if( pArg->statsOn==3 ){
    if( pArg->pStmt ){
      iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP,bReset);
      cli_printf(out, "VM-steps: %d\n", iCur);
    }
    return 0;
  }

  displayStatLine(out, "Memory Used:",
     "%lld (max %lld) bytes", SQLITE_STATUS_MEMORY_USED, bReset);
  displayStatLine(out, "Number of Outstanding Allocations:",
     "%lld (max %lld)", SQLITE_STATUS_MALLOC_COUNT, bReset);
  if( pArg->shellFlgs & SHFLG_Pagecache ){
    displayStatLine(out, "Number of Pcache Pages Used:",
       "%lld (max %lld) pages", SQLITE_STATUS_PAGECACHE_USED, bReset);
  }
  displayStatLine(out, "Number of Pcache Overflow Bytes:",
     "%lld (max %lld) bytes", SQLITE_STATUS_PAGECACHE_OVERFLOW, bReset);
  displayStatLine(out, "Largest Allocation:",
     "%lld bytes", SQLITE_STATUS_MALLOC_SIZE, bReset);
  displayStatLine(out, "Largest Pcache Allocation:",
     "%lld bytes", SQLITE_STATUS_PAGECACHE_SIZE, bReset);
#ifdef YYTRACKMAXSTACKDEPTH
  displayStatLine(out, "Deepest Parser Stack:",
     "%lld (max %lld)", SQLITE_STATUS_PARSER_STACK, bReset);
#endif

  if( db ){
    if( pArg->shellFlgs & SHFLG_Lookaside ){
      iHiwtr = iCur = -1;
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_USED,
                        &iCur, &iHiwtr, bReset);
      cli_printf(out, 
           "Lookaside Slots Used:                %d (max %d)\n", iCur, iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_HIT,
                        &iCur, &iHiwtr, bReset);
      cli_printf(out,
           "Successful lookaside attempts:       %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE,
                        &iCur, &iHiwtr, bReset);
      cli_printf(out,
           "Lookaside failures due to size:      %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL,
                        &iCur, &iHiwtr, bReset);
      cli_printf(out,
           "Lookaside failures due to OOM:       %d\n", iHiwtr);
    }
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_USED, &iCur, &iHiwtr, bReset);
    cli_printf(out,
           "Pager Heap Usage:                    %d bytes\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_HIT, &iCur, &iHiwtr, 1);
    cli_printf(out,
           "Page cache hits:                     %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_MISS, &iCur, &iHiwtr, 1);
    cli_printf(out,
           "Page cache misses:                   %d\n", iCur);
    iHiwtr64 = iCur64 = -1;
    sqlite3_db_status64(db, SQLITE_DBSTATUS_TEMPBUF_SPILL, &iCur64, &iHiwtr64,
                        0);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_WRITE, &iCur, &iHiwtr, 1);
    cli_printf(out,
           "Page cache writes:                   %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_SPILL, &iCur, &iHiwtr, 1);
    cli_printf(out,
           "Page cache spills:                   %d\n", iCur);
    cli_printf(out,
           "Temporary data spilled to disk:      %lld\n", iCur64);
    sqlite3_db_status64(db, SQLITE_DBSTATUS_TEMPBUF_SPILL, &iCur64, &iHiwtr64,
                        1);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_SCHEMA_USED, &iCur, &iHiwtr, bReset);
    cli_printf(out,
           "Schema Heap Usage:                   %d bytes\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_STMT_USED, &iCur, &iHiwtr, bReset);
    cli_printf(out,
           "Statement Heap/Lookaside Usage:      %d bytes\n", iCur);
  }

  if( pArg->pStmt ){
    int iHit, iMiss;
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FULLSCAN_STEP,
                               bReset);
    cli_printf(out,
           "Fullscan Steps:                      %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_SORT, bReset);
    cli_printf(out,
           "Sort Operations:                     %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_AUTOINDEX,bReset);
    cli_printf(out,
           "Autoindex Inserts:                   %d\n", iCur);
    iHit = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FILTER_HIT,
                               bReset);
    iMiss = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FILTER_MISS,
                                bReset);
    if( iHit || iMiss ){
      cli_printf(out,
           "Bloom filter bypass taken:           %d/%d\n", iHit, iHit+iMiss);
    }
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP, bReset);
    cli_printf(out,
           "Virtual Machine Steps:               %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_REPREPARE,bReset);
    cli_printf(out,
           "Reprepare operations:                %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_RUN, bReset);
    cli_printf(out,
           "Number of times run:                 %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_MEMUSED, bReset);
    cli_printf(out,
           "Memory used by prepared stmt:        %d\n", iCur);
  }

#ifdef __linux__
  displayLinuxIoStats(pArg->out);
#endif

  /* Do not remove this machine readable comment: extra-stats-output-here */

  return 0;
}

/*
** Disable and restore .wheretrace and .treetrace/.selecttrace settings.
*/
static unsigned int savedSelectTrace;
static unsigned int savedWhereTrace;
static void disable_debug_trace_modes(void){
  unsigned int zero = 0;
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 0, &savedSelectTrace);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 1, &zero);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 2, &savedWhereTrace);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 3, &zero);
}
static void restore_debug_trace_modes(void){
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 1, &savedSelectTrace);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 3, &savedWhereTrace);
}

/* Create the TEMP table used to store parameter bindings */
static void bind_table_init(ShellState *p){
  int wrSchema = 0;
  int defensiveMode = 0;
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, -1, &defensiveMode);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, -1, &wrSchema);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, 1, 0);
  sqlite3_exec(p->db,
    "CREATE TABLE IF NOT EXISTS temp.sqlite_parameters(\n"
    "  key TEXT PRIMARY KEY,\n"
    "  value\n"
    ") WITHOUT ROWID;",
    0, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, wrSchema, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, defensiveMode, 0);
}

/*
** Bind parameters on a prepared statement.
**
** Parameter bindings are taken from a TEMP table of the form:
**
**    CREATE TEMP TABLE sqlite_parameters(key TEXT PRIMARY KEY, value)
**    WITHOUT ROWID;
**
** No bindings occur if this table does not exist.  The name of the table
** begins with "sqlite_" so that it will not collide with ordinary application
** tables.  The table must be in the TEMP schema.
*/
static void bind_prepared_stmt(ShellState *pArg, sqlite3_stmt *pStmt){
  int nVar;
  int i;
  int rc;
  sqlite3_stmt *pQ = 0;

  nVar = sqlite3_bind_parameter_count(pStmt);
  if( nVar==0 ) return;  /* Nothing to do */
  if( sqlite3_table_column_metadata(pArg->db, "TEMP", "sqlite_parameters",
                                    "key", 0, 0, 0, 0, 0)!=SQLITE_OK ){
    rc = SQLITE_NOTFOUND;
    pQ = 0;
  }else{
    rc = sqlite3_prepare_v2(pArg->db,
            "SELECT value FROM temp.sqlite_parameters"
            " WHERE key=?1", -1, &pQ, 0);
  }
  for(i=1; i<=nVar; i++){
    char zNum[30];
    const char *zVar = sqlite3_bind_parameter_name(pStmt, i);
    if( zVar==0 ){
      sqlite3_snprintf(sizeof(zNum),zNum,"?%d",i);
      zVar = zNum;
    }
    sqlite3_bind_text(pQ, 1, zVar, -1, SQLITE_STATIC);
    if( rc==SQLITE_OK && pQ && sqlite3_step(pQ)==SQLITE_ROW ){
      sqlite3_bind_value(pStmt, i, sqlite3_column_value(pQ, 0));
#ifdef NAN
    }else if( sqlite3_strlike("_NAN", zVar, 0)==0 ){
      sqlite3_bind_double(pStmt, i, NAN);
#endif
#ifdef INFINITY
    }else if( sqlite3_strlike("_INF", zVar, 0)==0 ){
      sqlite3_bind_double(pStmt, i, INFINITY);
#endif
    }else if( strncmp(zVar, "$int_", 5)==0 ){
      sqlite3_bind_int(pStmt, i, atoi(&zVar[5]));
    }else if( strncmp(zVar, "$text_", 6)==0 ){
      size_t szVar = strlen(zVar);
      char *zBuf = sqlite3_malloc64( szVar-5 );
      if( zBuf ){
        memcpy(zBuf, &zVar[6], szVar-5);
        sqlite3_bind_text64(pStmt, i, zBuf, szVar-6, sqlite3_free, SQLITE_UTF8);
      }
    }else if( strcmp(zVar, "$TIMER")==0 ){
      sqlite3_bind_double(pStmt, i, pArg->prevTimer);
#ifdef SQLITE_ENABLE_CARRAY
    }else if( strncmp(zVar, "$carray_", 8)==0 ){
      static char *azColorNames[] = {
        "azure", "black", "blue",   "brown", "cyan",   "fuchsia", "gold",
        "gray",  "green", "indigo", "khaki", "lime",   "magenta", "maroon",
        "navy",  "olive", "orange", "pink",  "purple", "red",     "silver",
        "tan",   "teal",  "violet", "white", "yellow"
      };
      static int aPrimes[] = {
        1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47,
       53, 59, 61, 67, 71, 73, 79, 83, 89, 97
      };
      /* Special bindings:  carray($carray_clr), carray($carray_primes)
      ** with --unsafe-testing:  carray($carray_clr_p,26,'char*'),
      **                         carray($carray_primes_p,26,'int32')
      */
      if( strcmp(zVar+8,"clr")==0 ){
        sqlite3_carray_bind(pStmt,i,azColorNames,26,SQLITE_CARRAY_TEXT,0);
      }else if( strcmp(zVar+8,"primes")==0 ){
        sqlite3_carray_bind(pStmt,i,aPrimes,26,SQLITE_CARRAY_INT32,0);
      }else if( strcmp(zVar+8,"clr_p")==0
             && ShellHasFlag(pArg,SHFLG_TestingMode) ){
        sqlite3_bind_pointer(pStmt,i,azColorNames,"carray",0);
      }else if( strcmp(zVar+8,"primes_p")==0
             && ShellHasFlag(pArg,SHFLG_TestingMode) ){
        sqlite3_bind_pointer(pStmt,i,aPrimes,"carray",0);
      }else{
        sqlite3_bind_null(pStmt, i);
      }
#endif  
    }else{
      sqlite3_bind_null(pStmt, i);
    }
    sqlite3_reset(pQ);
  }
  sqlite3_finalize(pQ);
}

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
/*
** This function is called to process SQL if the previous shell command
** was ".expert". It passes the SQL in the second argument directly to
** the sqlite3expert object.
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error
** code. In this case, (*pzErr) may be set to point to a buffer containing
** an English language error message. It is the responsibility of the
** caller to eventually free this buffer using sqlite3_free().
*/
static int expertHandleSQL(
  ShellState *pState,
  const char *zSql,
  char **pzErr
){
  assert( pState->expert.pExpert );
  assert( pzErr==0 || *pzErr==0 );
  return sqlite3_expert_sql(pState->expert.pExpert, zSql, pzErr);
}

/*
** This function is called either to silently clean up the object
** created by the ".expert" command (if bCancel==1), or to generate a
** report from it and then clean it up (if bCancel==0).
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error
** code. In this case, (*pzErr) may be set to point to a buffer containing
** an English language error message. It is the responsibility of the
** caller to eventually free this buffer using sqlite3_free().
*/
static int expertFinish(
  ShellState *pState,
  int bCancel,
  char **pzErr
){
  int rc = SQLITE_OK;
  sqlite3expert *p = pState->expert.pExpert;
  FILE *out = pState->out;
  assert( p );
  assert( bCancel || pzErr==0 || *pzErr==0 );
  if( bCancel==0 ){
    int bVerbose = pState->expert.bVerbose;

    rc = sqlite3_expert_analyze(p, pzErr);
    if( rc==SQLITE_OK ){
      int nQuery = sqlite3_expert_count(p);
      int i;

      if( bVerbose ){
        const char *zCand = sqlite3_expert_report(p,0,EXPERT_REPORT_CANDIDATES);
        cli_puts("-- Candidates -----------------------------\n", out);
        cli_printf(out, "%s\n", zCand);
      }
      for(i=0; i<nQuery; i++){
        const char *zSql = sqlite3_expert_report(p, i, EXPERT_REPORT_SQL);
        const char *zIdx = sqlite3_expert_report(p, i, EXPERT_REPORT_INDEXES);
        const char *zEQP = sqlite3_expert_report(p, i, EXPERT_REPORT_PLAN);
        if( zIdx==0 ) zIdx = "(no new indexes)\n";
        if( bVerbose ){
          cli_printf(out,
              "-- Query %d --------------------------------\n"
              "%s\n\n"
              ,i+1, zSql);
        }
        cli_printf(out, "%s\n%s\n", zIdx, zEQP);
      }
    }
  }
  sqlite3_expert_destroy(p);
  pState->expert.pExpert = 0;
  return rc;
}

/*
** Implementation of ".expert" dot command.
*/
static int expertDotCommand(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  int rc = SQLITE_OK;
  char *zErr = 0;
  int i;
  int iSample = 0;

  assert( pState->expert.pExpert==0 );
  memset(&pState->expert, 0, sizeof(ExpertInfo));

  for(i=1; rc==SQLITE_OK && i<nArg; i++){
    char *z = azArg[i];
    int n;
    if( z[0]=='-' && z[1]=='-' ) z++;
    n = strlen30(z);
    if( n>=2 && 0==cli_strncmp(z, "-verbose", n) ){
      pState->expert.bVerbose = 1;
    }
    else if( n>=2 && 0==cli_strncmp(z, "-sample", n) ){
      if( i==(nArg-1) ){
        cli_printf(stderr, "option requires an argument: %s\n", z);
        rc = SQLITE_ERROR;
      }else{
        iSample = (int)integerValue(azArg[++i]);
        if( iSample<0 || iSample>100 ){
          cli_printf(stderr,"value out of range: %s\n", azArg[i]);
          rc = SQLITE_ERROR;
        }
      }
    }
    else{
      cli_printf(stderr,"unknown option: %s\n", z);
      rc = SQLITE_ERROR;
    }
  }

  if( rc==SQLITE_OK ){
    pState->expert.pExpert = sqlite3_expert_new(pState->db, &zErr);
    if( pState->expert.pExpert==0 ){
      cli_printf(stderr,
          "sqlite3_expert_new: %s\n", zErr ? zErr : "out of memory");
      rc = SQLITE_ERROR;
    }else{
      sqlite3_expert_config(
          pState->expert.pExpert, EXPERT_CONFIG_SAMPLE, iSample
      );
    }
  }
  sqlite3_free(zErr);

  return rc;
}
#endif /* !SQLITE_OMIT_VIRTUALTABLE && !SQLITE_OMIT_AUTHORIZATION */

/*
** QRF write callback
*/
static int shellWriteQR(void *pX, const char *z, sqlite3_int64 n){
  ShellState *pArg = (ShellState*)pX;
  cli_printf(pArg->out, "%.*s", (int)n, z);
  return SQLITE_OK;
}

/*
** Execute a statement or set of statements.  Print
** any result rows/columns depending on the current mode
** set via the supplied callback.
**
** This is very similar to SQLite's built-in sqlite3_exec()
** function except it takes a slightly different callback
** and callback data argument.
*/
static int shell_exec(
  ShellState *pArg,                         /* Pointer to ShellState */
  const char *zSql,                         /* SQL to be evaluated */
  char **pzErrMsg                           /* Error msg written here */
){
  sqlite3_stmt *pStmt = NULL;     /* Statement to execute. */
  int rc = SQLITE_OK;             /* Return Code */
  int rc2;
  const char *zLeftover;          /* Tail of unprocessed SQL */
  sqlite3 *db = pArg->db;
  unsigned char eStyle;
  sqlite3_qrf_spec spec;

  if( pzErrMsg ){
    *pzErrMsg = NULL;
  }
  memcpy(&spec, &pArg->mode.spec, sizeof(spec));
  spec.xWrite = shellWriteQR;
  spec.pWriteArg = (void*)pArg;
  if( pArg->mode.eMode==MODE_Insert && ShellHasFlag(pArg,SHFLG_PreserveRowid) ){
    spec.bTitles = QRF_SW_On;
  }
         /*                        ,- This is true, but it is omitted
         ** vvvvvvvvvvvvvvvvvvv ----- to avoid compiler warnings.         */
  assert( /*pArg->mode.eMode>=0 &&*/ pArg->mode.eMode<ArraySize(aModeInfo) );
  eStyle = aModeInfo[pArg->mode.eMode].eStyle;
  if( pArg->mode.bAutoScreenWidth ){
    spec.nScreenWidth = shellScreenWidth();
  }
  if( spec.eBlob==QRF_BLOB_Auto ){
    switch( spec.eText ){
      case QRF_TEXT_Relaxed: /* fall through */
      case QRF_TEXT_Sql:  spec.eBlob = QRF_BLOB_Sql;   break;
      case QRF_TEXT_Json: spec.eBlob = QRF_BLOB_Json;  break;
      default:            spec.eBlob = QRF_BLOB_Text;  break;
    }
  }

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
  if( pArg->expert.pExpert ){
    rc = expertHandleSQL(pArg, zSql, pzErrMsg);
    return expertFinish(pArg, (rc!=SQLITE_OK), pzErrMsg);
  }
#endif

  while( zSql && zSql[0] && (SQLITE_OK == rc) ){
    static const char *zStmtSql;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
    if( SQLITE_OK != rc ){
      if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db, "in prepare", rc, zSql);
      }
    }else{
      int isExplain;
      if( !pStmt ){
        /* this happens for a comment or white-space */
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
        continue;
      }
      zStmtSql = sqlite3_sql(pStmt);
      if( zStmtSql==0 ) zStmtSql = "";
      while( IsSpace(zStmtSql[0]) ) zStmtSql++;

      /* save off the prepared statement handle */
      if( pArg ){
        pArg->pStmt = pStmt;
      }
     
      /* Show the EXPLAIN QUERY PLAN if .eqp is on */
      isExplain = sqlite3_stmt_isexplain(pStmt);
      if( pArg && pArg->mode.autoEQP && isExplain==0 && pArg->dot.nArg==0 ){
        int triggerEQP = 0;
        u8 savedEnableTimer = pArg->enableTimer;
        pArg->enableTimer = 0;
        disable_debug_trace_modes();
        sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, -1, &triggerEQP);
        if( pArg->mode.autoEQP>=AUTOEQP_trigger ){
          sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 1, 0);
        }
        sqlite3_reset(pStmt);
        spec.eStyle = QRF_STYLE_Auto;
        sqlite3_stmt_explain(pStmt, 2);
        sqlite3_format_query_result(pStmt, &spec, 0);
        if( pArg->mode.autoEQP>=AUTOEQP_full ){
          sqlite3_reset(pStmt);
          sqlite3_stmt_explain(pStmt, 1);
          sqlite3_format_query_result(pStmt, &spec, 0);
        }

        if( pArg->mode.autoEQP>=AUTOEQP_trigger && triggerEQP==0 ){
          sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 0, 0);
        }
        sqlite3_reset(pStmt);
        sqlite3_stmt_explain(pStmt, 0);
        restore_debug_trace_modes();
        pArg->enableTimer = savedEnableTimer;
      }

      bind_prepared_stmt(pArg, pStmt);
      if( isExplain && pArg->mode.autoExplain ){
        spec.eStyle = isExplain==1 ? QRF_STYLE_Explain : QRF_STYLE_Eqp;
        sqlite3_format_query_result(pStmt, &spec, pzErrMsg);
      }else if( pArg->mode.eMode==MODE_Www ){
        cli_printf(pArg->out,
              "</PRE>\n"
              "<TABLE border='1' cellspacing='0' cellpadding='2'>\n");
        spec.eStyle = QRF_STYLE_Html;
        sqlite3_format_query_result(pStmt, &spec, pzErrMsg);
        cli_printf(pArg->out,
              "</TABLE>\n"
              "<PRE>");
      }else{
        spec.eStyle = eStyle;
        sqlite3_format_query_result(pStmt, &spec, pzErrMsg);
      }

      /* print usage stats if stats on */
      if( pArg && pArg->statsOn ){
        display_stats(db, pArg, 0);
      }

      /* print loop-counters if required */
      if( pArg && pArg->mode.scanstatsOn ){
        char *zErr = 0;
        switch( pArg->mode.scanstatsOn ){
          case 1:   spec.eStyle = QRF_STYLE_Stats;     break;
          case 2:   spec.eStyle = QRF_STYLE_StatsEst;  break;
          default:  spec.eStyle = QRF_STYLE_StatsVm;   break;
        }
        sqlite3_reset(pStmt);
        rc = sqlite3_format_query_result(pStmt, &spec, &zErr);
        if( rc ){
          cli_printf(stderr, "Stats query failed: %s\n", zErr);
          sqlite3_free(zErr);
        }          
      }

      /* Finalize the statement just executed. If this fails, save a
      ** copy of the error message. Otherwise, set zSql to point to the
      ** next statement to execute. */
      rc2 = sqlite3_finalize(pStmt);
      if( rc!=SQLITE_NOMEM ) rc = rc2;
      if( rc==SQLITE_OK ){
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
      }else if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db, "stepping", rc, 0);
      }

      /* clear saved stmt handle */
      if( pArg ){
        pArg->pStmt = NULL;
      }
    }
  } /* end while */

  return rc;
}

/*
** Release memory previously allocated by tableColumnList().
*/
static void freeColumnList(char **azCol){
  int i;
  for(i=1; azCol[i]; i++){
    sqlite3_free(azCol[i]);
  }
  /* azCol[0] is a static string */
  sqlite3_free(azCol);
}

/*
** Return a list of pointers to strings which are the names of all
** columns in table zTab.   The memory to hold the names is dynamically
** allocated and must be released by the caller using a subsequent call
** to freeColumnList().
**
** The azCol[0] entry is usually NULL.  However, if zTab contains a rowid
** value that needs to be preserved, then azCol[0] is filled in with the
** name of the rowid column.
**
** The first regular column in the table is azCol[1].  The list is terminated
** by an entry with azCol[i]==0.
*/
static char **tableColumnList(ShellState *p, const char *zTab){
  char **azCol = 0;
  sqlite3_stmt *pStmt;
  char *zSql;
  int nCol = 0;
  i64 nAlloc = 0;
  int nPK = 0;       /* Number of PRIMARY KEY columns seen */
  int isIPK = 0;     /* True if one PRIMARY KEY column of type INTEGER */
  int preserveRowid = ShellHasFlag(p, SHFLG_PreserveRowid);
  int rc;

  zSql = sqlite3_mprintf("PRAGMA table_info=%Q", zTab);
  shell_check_oom(zSql);
  rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  if( rc ) return 0;
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    if( nCol>=nAlloc-2 ){
      nAlloc = nAlloc*2 + nCol + 10;
      azCol = sqlite3_realloc64(azCol, nAlloc*sizeof(azCol[0]));
      shell_check_oom(azCol);
    }
    azCol[++nCol] = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 1));
    shell_check_oom(azCol[nCol]);
    if( sqlite3_column_int(pStmt, 5) ){
      nPK++;
      if( nPK==1
       && sqlite3_stricmp((const char*)sqlite3_column_text(pStmt,2),
                          "INTEGER")==0
      ){
        isIPK = 1;
      }else{
        isIPK = 0;
      }
    }
  }
  sqlite3_finalize(pStmt);
  if( azCol==0 ) return 0;
  azCol[0] = 0;
  azCol[nCol+1] = 0;

  /* The decision of whether or not a rowid really needs to be preserved
  ** is tricky.  We never need to preserve a rowid for a WITHOUT ROWID table
  ** or a table with an INTEGER PRIMARY KEY.  We are unable to preserve
  ** rowids on tables where the rowid is inaccessible because there are other
  ** columns in the table named "rowid", "_rowid_", and "oid".
  */
  if( preserveRowid && isIPK ){
    /* If a single PRIMARY KEY column with type INTEGER was seen, then it
    ** might be an alias for the ROWID.  But it might also be a WITHOUT ROWID
    ** table or a INTEGER PRIMARY KEY DESC column, neither of which are
    ** ROWID aliases.  To distinguish these cases, check to see if
    ** there is a "pk" entry in "PRAGMA index_list".  There will be
    ** no "pk" index if the PRIMARY KEY really is an alias for the ROWID.
    */
    zSql = sqlite3_mprintf("SELECT 1 FROM pragma_index_list(%Q)"
                           " WHERE origin='pk'", zTab);
    shell_check_oom(zSql);
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    if( rc ){
      freeColumnList(azCol);
      return 0;
    }
    rc = sqlite3_step(pStmt);
    sqlite3_finalize(pStmt);
    preserveRowid = rc==SQLITE_ROW;
  }
  if( preserveRowid ){
    /* Only preserve the rowid if we can find a name to use for the
    ** rowid */
    static char *azRowid[] = { "rowid", "_rowid_", "oid" };
    int i, j;
    for(j=0; j<3; j++){
      for(i=1; i<=nCol; i++){
        if( sqlite3_stricmp(azRowid[j],azCol[i])==0 ) break;
      }
      if( i>nCol ){
        /* At this point, we know that azRowid[j] is not the name of any
        ** ordinary column in the table.  Verify that azRowid[j] is a valid
        ** name for the rowid before adding it to azCol[0].  WITHOUT ROWID
        ** tables will fail this last check */
        rc = sqlite3_table_column_metadata(p->db,0,zTab,azRowid[j],0,0,0,0,0);
        if( rc==SQLITE_OK ) azCol[0] = azRowid[j];
        break;
      }
    }
  }
  return azCol;
}

/*
** Toggle the reverse_unordered_selects setting.
*/
static void toggleSelectOrder(sqlite3 *db){
  sqlite3_stmt *pStmt = 0;
  int iSetting = 0;
  char zStmt[100];
  sqlite3_prepare_v2(db, "PRAGMA reverse_unordered_selects", -1, &pStmt, 0);
  if( sqlite3_step(pStmt)==SQLITE_ROW ){
    iSetting = sqlite3_column_int(pStmt, 0);
  }
  sqlite3_finalize(pStmt);
  sqlite3_snprintf(sizeof(zStmt), zStmt,
       "PRAGMA reverse_unordered_selects(%d)", !iSetting);
  sqlite3_exec(db, zStmt, 0, 0, 0);
}

/* Forward reference */
static int db_int(sqlite3 *db, const char *zSql, ...);

/*
** This is a different callback routine used for dumping the database.
** Each row received by this callback consists of a table name,
** the table type ("index" or "table") and SQL to create the table.
** This routine should print text sufficient to recreate the table.
*/
static int dump_callback(void *pArg, int nArg, char **azArg, char **azNotUsed){
  int rc;
  const char *zTable;
  const char *zType;
  const char *zSql;
  ShellState *p = (ShellState *)pArg;
  int dataOnly;
  int noSys;

  UNUSED_PARAMETER(azNotUsed);
  if( nArg!=3 || azArg==0 ) return 0;
  zTable = azArg[0];
  zType = azArg[1];
  zSql = azArg[2];
  if( zTable==0 ) return 0;
  if( zType==0 ) return 0;
  dataOnly = (p->shellFlgs & SHFLG_DumpDataOnly)!=0;
  noSys    = (p->shellFlgs & SHFLG_DumpNoSys)!=0;

  if( cli_strcmp(zTable, "sqlite_sequence")==0 && !noSys ){
    /* The sqlite_sequence table is repopulated last.  Delete content
    ** in the sqlite_sequence table added by prior repopulations prior to
    ** repopulating sqlite_sequence itself.  But only do this if the
    ** table is non-empty, because if it is empty the table might not
    ** have been recreated by prior repopulations. See forum posts:
    ** 2024-10-13T17:10:01z and 2025-10-29T19:38:43z
    */
    if( db_int(p->db, "SELECT count(*) FROM sqlite_sequence")>0 ){
      if( !p->writableSchema ){
        cli_puts("PRAGMA writable_schema=ON;\n", p->out);
        p->writableSchema = 1;
      }
      cli_puts("CREATE TABLE IF NOT EXISTS sqlite_sequence(name,seq);\n"
                    "DELETE FROM sqlite_sequence;\n", p->out);
    }
  }else if( sqlite3_strglob("sqlite_stat?", zTable)==0 && !noSys ){
    if( !dataOnly ) cli_puts("ANALYZE sqlite_schema;\n", p->out);
  }else if( cli_strncmp(zTable, "sqlite_", 7)==0 ){
    return 0;
  }else if( dataOnly ){
    /* no-op */
  }else if( cli_strncmp(zSql, "CREATE VIRTUAL TABLE", 20)==0 ){
    char *zIns;
    if( !p->writableSchema ){
      cli_puts("PRAGMA writable_schema=ON;\n", p->out);
      p->writableSchema = 1;
    }
    zIns = sqlite3_mprintf(
       "INSERT INTO sqlite_schema(type,name,tbl_name,rootpage,sql)"
       "VALUES('table','%q','%q',0,'%q');",
       zTable, zTable, zSql);
    shell_check_oom(zIns);
    cli_printf(p->out, "%s\n", zIns);
    sqlite3_free(zIns);
    return 0;
  }else{
    printSchemaLine(p->out, zSql, ";\n");
  }

  if( cli_strcmp(zType, "table")==0 ){
    ShellText sSelect;
    ShellText sTable;
    char **azCol;
    int i;
    Mode savedMode;

    azCol = tableColumnList(p, zTable);
    if( azCol==0 ){
      p->nErr++;
      return 0;
    }

    /* Always quote the table name, even if it appears to be pure ascii,
    ** in case it is a keyword. Ex:  INSERT INTO "table" ... */
    initText(&sTable);
    appendText(&sTable, zTable, quoteChar(zTable));
    /* If preserving the rowid, add a column list after the table name.
    ** In other words:  "INSERT INTO tab(rowid,a,b,c,...) VALUES(...)"
    ** instead of the usual "INSERT INTO tab VALUES(...)".
    */
    if( azCol[0] ){
      appendText(&sTable, "(", 0);
      appendText(&sTable, azCol[0], 0);
      for(i=1; azCol[i]; i++){
        appendText(&sTable, ",", 0);
        appendText(&sTable, azCol[i], quoteChar(azCol[i]));
      }
      appendText(&sTable, ")", 0);
    }

    /* Build an appropriate SELECT statement */
    initText(&sSelect);
    appendText(&sSelect, "SELECT ", 0);
    if( azCol[0] ){
      appendText(&sSelect, azCol[0], 0);
      appendText(&sSelect, ",", 0);
    }
    for(i=1; azCol[i]; i++){
      appendText(&sSelect, azCol[i], quoteChar(azCol[i]));
      if( azCol[i+1] ){
        appendText(&sSelect, ",", 0);
      }
    }
    freeColumnList(azCol);
    appendText(&sSelect, " FROM ", 0);
    appendText(&sSelect, zTable, quoteChar(zTable));


    savedMode = p->mode;
    p->mode.spec.zTableName = (char*)zTable;
    p->mode.eMode = MODE_Insert;
    p->mode.spec.eText = QRF_TEXT_Sql;
    p->mode.spec.eBlob = QRF_BLOB_Sql;
    p->mode.spec.bTitles = QRF_No;
    p->mode.spec.nCharLimit = 0;
    rc = shell_exec(p, sSelect.zTxt, 0);
    if( (rc&0xff)==SQLITE_CORRUPT ){
      cli_puts("/****** CORRUPTION ERROR *******/\n", p->out);
      toggleSelectOrder(p->db);
      shell_exec(p, sSelect.zTxt, 0);
      toggleSelectOrder(p->db);
    }
    p->mode = savedMode;
    freeText(&sTable);
    freeText(&sSelect);
    if( rc ) p->nErr++;
  }
  return 0;
}

/*
** Run zQuery.  Use dump_callback() as the callback routine so that
** the contents of the query are output as SQL statements.
**
** If we get a SQLITE_CORRUPT error, rerun the query after appending
** "ORDER BY rowid DESC" to the end.
*/
static int run_schema_dump_query(
  ShellState *p,
  const char *zQuery
){
  int rc;
  char *zErr = 0;
  rc = sqlite3_exec(p->db, zQuery, dump_callback, p, &zErr);
  if( rc==SQLITE_CORRUPT ){
    char *zQ2;
    int len = strlen30(zQuery);
    cli_puts("/****** CORRUPTION ERROR *******/\n", p->out);
    if( zErr ){
      cli_printf(p->out, "/****** %s ******/\n", zErr);
      sqlite3_free(zErr);
      zErr = 0;
    }
    zQ2 = malloc( len+100 );
    if( zQ2==0 ) return rc;
    sqlite3_snprintf(len+100, zQ2, "%s ORDER BY rowid DESC", zQuery);
    rc = sqlite3_exec(p->db, zQ2, dump_callback, p, &zErr);
    if( rc ){
      cli_printf(p->out, "/****** ERROR: %s ******/\n", zErr);
    }else{
      rc = SQLITE_CORRUPT;
    }
    free(zQ2);
  }
  sqlite3_free(zErr);
  return rc;
}

/*
** Text of help messages.
**
** The help text for each individual command begins with a line that starts
** with ".".  Subsequent lines are supplemental information.
**
** There must be two or more spaces between the end of the command and the
** start of the description of what that command does.
*/
static const char *(azHelp[]) = {
#if defined(SQLITE_HAVE_ZLIB) && !defined(SQLITE_OMIT_VIRTUALTABLE) \
  && !defined(SQLITE_SHELL_FIDDLE)
  ".archive ...             Manage SQL archives",
  "   Each command must have exactly one of the following options:",
  "     -c, --create               Create a new archive",
  "     -u, --update               Add or update files with changed mtime",
  "     -i, --insert               Like -u but always add even if unchanged",
  "     -r, --remove               Remove files from archive",
  "     -t, --list                 List contents of archive",
  "     -x, --extract              Extract files from archive",
  "   Optional arguments:",
  "     -v, --verbose              Print each filename as it is processed",
  "     -f FILE, --file FILE       Use archive FILE (default is current db)",
  "     -a FILE, --append FILE     Open FILE using the apndvfs VFS",
  "     -C DIR, --directory DIR    Read/extract files from directory DIR",
  "     -g, --glob                 Use glob matching for names in archive",
  "     -n, --dryrun               Show the SQL that would have occurred",
  "   Examples:",
  "     .ar -cf ARCHIVE foo bar  # Create ARCHIVE from files foo and bar",
  "     .ar -tf ARCHIVE          # List members of ARCHIVE",
  "     .ar -xvf ARCHIVE         # Verbosely extract files from ARCHIVE",
  "   See also:",
  "      http://sqlite.org/cli.html#sqlite_archive_support",
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
  ".auth ON|OFF             Show authorizer callbacks",
#endif
#ifndef SQLITE_SHELL_FIDDLE
  ".backup ?DB? FILE        Backup DB (default \"main\") to FILE",
  "   Options:",
  "       --append            Use the appendvfs",
  "       --async             Write to FILE without journal and fsync()",
#endif
  ".bail on|off             Stop after hitting an error.  Default OFF",
#ifndef SQLITE_SHELL_FIDDLE
  ".cd DIRECTORY            Change the working directory to DIRECTORY",
#endif
  ".changes on|off          Show number of rows changed by SQL",
  ".check OPTIONS ...       Verify the results of a .testcase",
#ifndef SQLITE_SHELL_FIDDLE
  ".clone NEWDB             Clone data into NEWDB from the existing database",
#endif
  ".connection [close] [#]  Open or close an auxiliary database connection",
  ".crlf ?on|off?           Whether or not to use \\r\\n line endings",
  ".databases               List names and files of attached databases",
  ".dbconfig ?op? ?val?     List or change sqlite3_db_config() options",
#if SQLITE_SHELL_HAVE_RECOVER
  ".dbinfo ?DB?             Show status information about the database",
#endif
  ".dbtotxt                 Hex dump of the database file",
  ".dump ?OBJECTS?          Render database content as SQL",
  "   Options:",
  "     --data-only            Output only INSERT statements",
  "     --newlines             Allow unescaped newline characters in output",
  "     --nosys                Omit system tables (ex: \"sqlite_stat1\")",
  "     --preserve-rowids      Include ROWID values in the output",
  "   OBJECTS is a LIKE pattern for tables, indexes, triggers or views to dump",
  "   Additional LIKE patterns can be given in subsequent arguments",
  ".echo on|off             Turn command echo on or off",
  ".eqp on|off|full|...     Enable or disable automatic EXPLAIN QUERY PLAN",
  "   Other Modes:",
#ifdef SQLITE_DEBUG
  "      test                  Show raw EXPLAIN QUERY PLAN output",
  "      trace                 Like \"full\" but enable \"PRAGMA vdbe_trace\"",
#endif
  "      trigger               Like \"full\" but also show trigger bytecode",
#ifndef SQLITE_SHELL_FIDDLE
  ".excel                   Display the output of next command in spreadsheet",
  "   --bom                   Put a UTF8 byte-order mark on intermediate file",
#endif
#ifndef SQLITE_SHELL_FIDDLE
  ".exit ?CODE?             Exit this program with return-code CODE",
#endif
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
  ".expert                  EXPERIMENTAL. Suggest indexes for queries",
#endif
  ".explain ?on|off|auto?   Change the EXPLAIN formatting mode.  Default: auto",
  ".filectrl CMD ...        Run various sqlite3_file_control() operations",
  "   --schema SCHEMA         Use SCHEMA instead of \"main\"",
  "   --help                  Show CMD details",
  ".fullschema ?--indent?   Show schema and the content of sqlite_stat tables",
  ",headers on|off          Turn display of headers on or off",
  ".help ?-all? ?PATTERN?   Show help text for PATTERN",
#ifndef SQLITE_SHELL_FIDDLE
  ".import FILE TABLE       Import data from FILE into TABLE",
#endif
#ifndef SQLITE_OMIT_TEST_CONTROL
  ".imposter INDEX TABLE    Create imposter table TABLE on index INDEX",
#endif
  ".indexes ?PATTERN?       Show names of indexes matching PATTERN",
  "   -a|--all                Also show system-generated indexes",
  "   --expr                  Show only expression indexes",
  "   --sys                   Show only system-generated indexes",
  ".intck ?STEPS_PER_UNLOCK?  Run an incremental integrity check on the db",
#ifdef SQLITE_ENABLE_IOTRACE
  ",iotrace FILE            Enable I/O diagnostic logging to FILE",
#endif
  ".limit ?LIMIT? ?VAL?     Display or change the value of an SQLITE_LIMIT",
  ".lint OPTIONS            Report potential schema issues.",
  "     Options:",
  "        fkey-indexes     Find missing foreign key indexes",
#if !defined(SQLITE_OMIT_LOAD_EXTENSION) && !defined(SQLITE_SHELL_FIDDLE)
  ".load FILE ?ENTRY?       Load an extension library",
#endif
#if !defined(SQLITE_SHELL_FIDDLE)
  ".log FILE|on|off         Turn logging on or off.  FILE can be stderr/stdout",
#else
  ".log on|off              Turn logging on or off.",
#endif
  ".mode ?MODE? ?OPTIONS?   Set output mode",
#ifndef SQLITE_SHELL_FIDDLE
  ".nonce STRING            Suspend safe mode for one command if nonce matches",
#endif
  ".nullvalue STRING        Use STRING in place of NULL values",
#ifndef SQLITE_SHELL_FIDDLE
  ".once ?OPTIONS? ?FILE?   Output for the next SQL command only to FILE",
  /* Note that .open is (partially) available in WASM builds but is
  ** currently only intended to be used by the fiddle tool, not
  ** end users, so is "undocumented." */
  ".open ?OPTIONS? ?FILE?   Close existing database and reopen FILE",
  "     Options:",
  "        --append        Use appendvfs to append database to the end of FILE",
#endif
#ifndef SQLITE_OMIT_DESERIALIZE
  "        --deserialize   Load into memory using sqlite3_deserialize()",
#endif
/*"        --exclusive     Set the SQLITE_OPEN_EXCLUSIVE flag", UNDOCUMENTED */
#ifndef SQLITE_OMIT_DESERIALIZE
  "        --hexdb         Load the output of \"dbtotxt\" as an in-memory db",
#endif
  "        --ifexist       Only open if FILE already exists",
#ifndef SQLITE_OMIT_DESERIALIZE
  "        --maxsize N     Maximum size for --hexdb or --deserialized database",
#endif
  "        --new           Initialize FILE to an empty database",
  "        --normal        FILE is an ordinary SQLite database",
  "        --nofollow      Do not follow symbolic links",
  "        --readonly      Open FILE readonly",
  "        --zip           FILE is a ZIP archive",
#ifndef SQLITE_SHELL_FIDDLE
  ".output ?FILE?           Send output to FILE or stdout if FILE is omitted",
#endif
  ".parameter CMD ...       Manage SQL parameter bindings",
  "   clear                   Erase all bindings",
  "   init                    Initialize the TEMP table that holds bindings",
  "   list                    List the current parameter bindings",
  "   set PARAMETER VALUE     Given SQL parameter PARAMETER a value of VALUE",
  "                           PARAMETER should start with one of: $ : @ ?",
  "   unset PARAMETER         Remove PARAMETER from the binding table",
  ".print STRING...         Print literal STRING",
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  ".progress N              Invoke progress handler after every N opcodes",
  "   --limit N                 Interrupt after N progress callbacks",
  "   --once                    Do no more than one progress interrupt",
  "   --quiet|-q                No output except at interrupts",
  "   --reset                   Reset the count for each input and interrupt",
  "   --timeout S               Halt after running for S seconds",
#endif
  ".prompt MAIN CONTINUE    Replace the standard prompts",
#ifndef SQLITE_SHELL_FIDDLE
  ".quit                    Stop interpreting input stream, exit if primary.",
  ".read FILE               Read input from FILE or command output",
  "    If FILE begins with \"|\", it is a command that generates the input.",
#endif
#if SQLITE_SHELL_HAVE_RECOVER
  ".recover                 Recover as much data as possible from corrupt db.",
  "   --ignore-freelist        Ignore pages that appear to be on db freelist",
  "   --lost-and-found TABLE   Alternative name for the lost-and-found table",
  "   --no-rowids              Do not attempt to recover rowid values",
  "                            that are not also INTEGER PRIMARY KEYs",
#endif
#ifndef SQLITE_SHELL_FIDDLE
  ".restore ?DB? FILE       Restore content of DB (default \"main\") from FILE",
  ".save ?OPTIONS? FILE     Write database to FILE (an alias for .backup ...)",
#endif
  ".scanstats on|off|est    Turn sqlite3_stmt_scanstatus() metrics on or off",
  ".schema ?PATTERN?        Show the CREATE statements matching PATTERN",
  "   Options:",
  "      --indent             Try to pretty-print the schema",
  "      --nosys              Omit objects whose names start with \"sqlite_\"",
  ",selftest ?OPTIONS?      Run tests defined in the SELFTEST table",
  "    Options:",
  "       --init               Create a new SELFTEST table",
  "       -v                   Verbose output",
  ",separator COL ?ROW?     Change the column and row separators",
#if defined(SQLITE_ENABLE_SESSION)
  ".session ?NAME? CMD ...  Create or control sessions",
  "   Subcommands:",
  "     attach TABLE             Attach TABLE",
  "     changeset FILE           Write a changeset into FILE",
  "     close                    Close one session",
  "     enable ?BOOLEAN?         Set or query the enable bit",
  "     filter GLOB...           Reject tables matching GLOBs",
  "     indirect ?BOOLEAN?       Mark or query the indirect status",
  "     isempty                  Query whether the session is empty",
  "     list                     List currently open session names",
  "     open DB NAME             Open a new session on DB",
  "     patchset FILE            Write a patchset into FILE",
  "   If ?NAME? is omitted, the first defined session is used.",
#endif
  ".sha3sum ...             Compute a SHA3 hash of database content",
  "    Options:",
  "      --schema              Also hash the sqlite_schema table",
  "      --sha3-224            Use the sha3-224 algorithm",
  "      --sha3-256            Use the sha3-256 algorithm (default)",
  "      --sha3-384            Use the sha3-384 algorithm",
  "      --sha3-512            Use the sha3-512 algorithm",
  "    Any other argument is a LIKE pattern for tables to hash",
#if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
  ".shell CMD ARGS...       Run CMD ARGS... in a system shell",
#endif
  ",show                    Show the current values for various settings",
  ".stats ?ARG?             Show stats or turn stats on or off",
  "   off                      Turn off automatic stat display",
  "   on                       Turn on automatic stat display",
  "   stmt                     Show statement stats",
  "   vmstep                   Show the virtual machine step count only",
#if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
  ".system CMD ARGS...      Run CMD ARGS... in a system shell",
#endif
  ".tables ?TABLE?          List names of tables matching LIKE pattern TABLE",
  ".testcase NAME           Begin a test case.",
  ",testctrl CMD ...        Run various sqlite3_test_control() operations",
  "                           Run \".testctrl\" with no arguments for details",
  ".timeout MS              Try opening locked tables for MS milliseconds",
  ".timer on|off|once       Turn SQL timer on or off.",
#ifndef SQLITE_OMIT_TRACE
  ".trace ?OPTIONS?         Output each SQL statement as it is run",
  "    FILE                    Send output to FILE",
  "    stdout                  Send output to stdout",
  "    stderr                  Send output to stderr",
  "    off                     Disable tracing",
  "    --expanded              Expand query parameters",
#ifdef SQLITE_ENABLE_NORMALIZE
  "    --normalized            Normal the SQL statements",
#endif
  "    --plain                 Show SQL as it is input",
  "    --stmt                  Trace statement execution (SQLITE_TRACE_STMT)",
  "    --profile               Profile statements (SQLITE_TRACE_PROFILE)",
  "    --row                   Trace each row (SQLITE_TRACE_ROW)",
  "    --close                 Trace connection close (SQLITE_TRACE_CLOSE)",
#endif /* SQLITE_OMIT_TRACE */
#ifdef SQLITE_DEBUG
  ".unmodule NAME ...       Unregister virtual table modules",
  "    --allexcept             Unregister everything except those named",
#endif
  ".version                 Show source, library and compiler versions",
  ".vfsinfo ?AUX?           Information about the top-level VFS",
  ".vfslist                 List all available VFSes",
  ".vfsname ?AUX?           Print the name of the VFS stack",
  ",width NUM1 NUM2 ...     Set minimum column widths for columnar output",
  "     Negative values right-justify",
#ifndef SQLITE_SHELL_FIDDLE
  ".www                     Display output of the next command in web browser",
  "    --plain                 Show results as text/plain, not as HTML",
#endif
};

/**************************************************************
** "Usage" help text automatically generated from comments */
static const struct {
  const char *zCmd;   /* Name of the dot-command */
  const char *zUsage; /* Documentation */
} aUsage[] = {
  { ".import",
"USAGE: .import [OPTIONS] FILE TABLE\n"
"\n"
"Import CSV or similar text from FILE into TABLE.  If TABLE does\n"
"not exist, it is created using the first row of FILE as the column\n"
"names.  If FILE begins with \"|\" then it is a command that is run\n"
"and the output from the command is used as the input data.  If\n"
"FILE begins with \"<<\" followed by a label, then content is read from\n"
"the script until the first line that matches the label.\n"
"\n"
"The content of FILE is interpreted using RFC-4180 (\"CSV\") quoting\n"
"rules unless the current mode is \"ascii\" or \"tabs\" or unless one\n"
"the --ascii option is used.\n"
"\n"
"The column and row separators must be single ASCII characters.  If\n"
"multiple characters or a Unicode character are specified for the\n"
"separators, then only the first byte of the separator is used.  Except,\n"
"if the row separator is \\n and the mode is not --ascii, then \\r\\n is\n"
"understood as a row separator too.\n"
"\n"
"Options:\n"
"  --ascii         Do not use RFC-4180 quoting.  Use \\037 and \\036\n"
"                  as column and row separators on input, unless other\n"
"                  delimiters are specified using --colsep and/or --rowsep\n"
"  --colsep CHAR   Use CHAR as the column separator.\n"
"  --csv           Input is standard RFC-4180 CSV.\n"
"  --esc CHAR      Use CHAR as an escape character in unquoted CSV inputs.\n"
"  --qesc CHAR     Use CHAR as an escape character in quoted CSV inputs.\n"
"  --rowsep CHAR   Use CHAR as the row separator.\n"
"  --schema S      When creating TABLE, put it in schema S\n"
"  --skip N        Ignore the first N rows of input\n"
"  -v              Verbose mode\n"
  },
  { ".mode",
"USAGE: .mode [MODE] [OPTIONS]\n"
"\n"
"Change the output mode to MODE and/or apply OPTIONS to the output mode.\n"
"Arguments are processed from left to right.  If no arguments, show the\n"
"current output mode and relevant options.\n"
"\n"
"Options:\n"
"  --align STRING           Set the alignment of text in columnar modes\n"
"                           String consists of characters 'L', 'C', 'R'\n"
"                           meaning \"left\", \"centered\", and \"right\", with\n"
"                           one letter per column starting from the left.\n"
"                           Unspecified alignment defaults to 'L'.\n"
"  --blob-quote ARG         ARG can be \"auto\", \"text\", \"sql\", \"hex\", \"tcl\",\n"
"                           \"json\", or \"size\".  Default is \"auto\".\n"
"  --border on|off          Show outer border on \"box\" and \"table\" modes.\n"
"  --charlimit N            Set the maximum number of output characters to\n"
"                           show for any single SQL value to N. Longer values\n"
"                           truncated. Zero means \"no limit\".\n"
"  --colsep STRING          Use STRING as the column separator\n"
"  --escape ESC             Enable/disable escaping of control characters\n"
"                           found in the output. ESC can be \"off\", \"ascii\",\n"
"                           or \"symbol\".\n"
"  --linelimit N            Set the maximum number of output lines to show for\n"
"                           any single SQL value to N. Longer values are\n"
"                           truncated. Zero means \"no limit\". Only works\n"
"                           in \"line\" mode and in columnar modes.\n"
"  --limits L,C,T           Shorthand for \"--linelimit L --charlimit C\n"
"                           --titlelimit T\". The \",T\" can be omitted in which\n"
"                           case the --titlelimit is unchanged.  The argument\n"
"                           can also be \"off\" to mean \"0,0,0\" or \"on\" to\n"
"                           mean \"5,300,20\".\n"
"  --list                   List available modes\n"
"  --multiinsert N          In \"insert\" mode, put multiple rows on a single\n"
"                           INSERT statement until the size exceeds N bytes.\n"
"  --null STRING            Render SQL NULL values as the given string\n"
"  --once                   Setting changes to the right are reverted after\n"
"                           the next SQL command.\n"
"  --quote ARG              Enable/disable quoting of text. ARG can be\n"
"                           \"off\", \"on\", \"sql\", \"relaxed\", \"csv\", \"html\",\n"
"                           \"tcl\", or \"json\". \"off\" means show the text as-is.\n"
"                           \"on\" is an alias for \"sql\".\n"
"  --reset                  Changes all mode settings back to their default.\n"
"  --rowsep STRING          Use STRING as the row separator\n"
"  --sw|--screenwidth N     Declare the screen width of the output device\n"
"                           to be N characters.  An attempt may be made to\n"
"                           wrap output text to fit within this limit. Zero\n"
"                           means \"no limit\".  Or N can be \"auto\" to set the\n"
"                           width automatically.\n"
"  --tablename NAME         Set the name of the table for \"insert\" mode.\n"
"  --tag NAME               Save mode to the left as NAME.\n"
"  --textjsonb BOOLEAN      If enabled, JSONB text is displayed as text JSON.\n"
"  --title ARG              Whether or not to show column headers, and if so\n"
"                           how to encode them.  ARG can be \"off\", \"on\",\n"
"                           \"sql\", \"csv\", \"html\", \"tcl\", or \"json\".\n"
"  --titlelimit N           Limit the length of column titles to N characters.\n"
"  -v|--verbose             Verbose output\n"
"  --widths LIST            Set the columns widths for columnar modes. The\n"
"                           argument is a list of integers, one for each\n"
"                           column. A \"0\" width means use a dynamic width\n"
"                           based on the actual width of data. If there are\n"
"                           fewer entries in LIST than columns, \"0\" is used\n"
"                           for the unspecified widths.\n"
"  --wordwrap BOOLEAN       Enable/disable word wrapping\n"
"  --wrap N                 Wrap columns wider than N characters\n"
"  --ww                     Shorthand for \"--wordwrap on\"\n"
  },
  { ".output",
"USAGE: .output [OPTIONS] [FILE]\n"
"\n"
"Begin redirecting output to FILE.  Or if FILE is omitted, revert\n"
"to sending output to the console.  If FILE begins with \"|\" then\n"
"the remainder of file is taken as a pipe and output is directed\n"
"into that pipe.  If FILE is \"memory\" then output is captured in an\n"
"internal memory buffer.  If FILE is \"off\" then output is redirected\n"
"into /dev/null or the equivalent.\n"
"\n"
"Options:\n"
"  --bom             Prepend a byte-order mark to the output\n"
"  -e                Accumulate output in a temporary text file then\n"
"                    launch a text editor when the redirection ends.\n"
"  --error-prefix X  Use X as the left-margin prefix for error messages.\n"
"                    Set to an empty string to restore the default.\n"
"  --keep            Keep redirecting output to its current destination.\n"
"                    Use this option in combination with --show or\n"
"                    with --error-prefix when you do not want to stop\n"
"                    a current redirection.\n"
"  --plain           Use plain text rather than HTML tables with -w\n"
"  --show            Show output text captured by .testcase or by\n"
"                    redirecting to \"memory\".\n"
"  -w                Show the output in a web browser.  Output is\n"
"                    written into a temporary HTML file until the\n"
"                    redirect ends, then the web browser is launched.\n"
"                    Query results  are shown as HTML tables, unless\n"
"                    the --plain is used too.\n"
"  -x                Show the output in a spreadsheet.  Output is\n"
"                    written to a temp file as CSV then the spreadsheet\n"
"                    is launched when\n"
  },
  { ".once",
"USAGE: .once [OPTIONS] FILE ...\n"
"\n"
"Write the output for the next line of SQL or the next dot-command into\n"
"FILE.  If FILE begins with \"|\" then it is a program into which output\n"
"is written. The FILE argument should be omitted if one of the -e, -w,\n"
"or -x options is used.\n"
"\n"
"Options:\n"
"  -e                Capture output into a temporary file then bring up\n"
"                    a text editor on that temporary file.\n"
"  --plain           Use plain text rather than HTML tables with -w\n"
"  -w                Capture output into an HTML file then bring up that\n"
"                    file in a web browser\n"
"  -x                Show the output in a spreadsheet.  Output is\n"
"                    written to a temp file as CSV then the spreadsheet\n"
"                    is launched when\n"
  },
  { ".check",
"USAGE: .check [OPTIONS] PATTERN\n"
"\n"
"Verify results of commands since the most recent .testcase command.\n"
"Restore output to the console, unless --keep is used.\n"
"\n"
"If PATTERN starts with \"<<ENDMARK\" then the actual pattern is taken from\n"
"subsequent lines of text up to the first line that begins with ENDMARK.\n"
"All pattern lines and the ENDMARK are discarded.\n"
"\n"
"Options:\n"
"  --exact                Do an exact comparison including leading and\n"
"                         trailing whitespace.\n"
"  --glob                 Treat PATTERN as a GLOB\n"
"  --keep                 Do not reset the testcase.  More .check commands\n"
"                         will follow.\n"
"  --notglob              Output should not match PATTERN\n"
"  --show                 Write testcase output to the screen, for debugging.\n"
  },
  { ".testcase",
"USAGE: .testcase [OPTIONS] NAME\n"
"\n"
"Start a new test case identified by NAME.  All output\n"
"through the next \".check\" command is captured for comparison. See the\n"
"\".check\" commandn for additional informatioon.\n"
"\n"
"Options:\n"
"  --error-prefix TEXT       Change error message prefix text to TEXT\n"
  },
};

/*
** Return a pointer to usage text for zCmd, or NULL if none exists.
*/
static const char *findUsage(const char *zCmd){
  int i;
  for(i=0; i<ArraySize(aUsage); i++){
    if( sqlite3_strglob(zCmd, aUsage[i].zCmd)==0 ) return aUsage[i].zUsage;
  }
  return 0;
}

/*
** Output help text for commands that match zPattern.
**
**    *   If zPattern is NULL, then show all documented commands, but
**        only give a one-line summary of each.
**
**    *   If zPattern is "-a" or "-all" or "--all" then show all help text
**        for all commands except undocumented commands.
**
**    *   If zPattern is "0" then show all help for undocumented commands.
**        Undocumented commands begin with "," instead of "." in the azHelp[]
**        array.
**
**    *   If zPattern is a prefix for one or more documented commands, then
**        show help for those commands.  If only a single command matches the
**        prefix, show the full text of the help.  If multiple commands match,
**        Only show just the first line of each.
**
**    *   Otherwise, show the complete text of any documented command for which
**        zPattern is a LIKE match for any text within that command help
**        text.
**
** Return the number commands that match zPattern.
*/
static int showHelp(FILE *out, const char *zPattern){
  int i = 0;
  int j = 0;
  int n = 0;
  char *zPat;
  const char *zHit = 0;
  if( zPattern==0 ){
    /* Show just the first line for all help topics */
    zPattern = "[a-z]";
  }else if( cli_strcmp(zPattern,"-a")==0
         || cli_strcmp(zPattern,"-all")==0
         || cli_strcmp(zPattern,"--all")==0
  ){
    /* Show everything except undocumented commands */
    zPattern = ".";
  }else if( cli_strcmp(zPattern,"0")==0 ){
    /* Show complete help text of undocumented commands */
    int show = 0;
    for(i=0; i<ArraySize(azHelp); i++){
      if( azHelp[i][0]=='.' ){
        show = 0;
      }else if( azHelp[i][0]==',' ){
        show = 1;
        cli_printf(out, ".%s\n", &azHelp[i][1]);
        n++;
      }else if( show ){
        cli_printf(out, "%s\n", azHelp[i]);
      }
    }
    return n;
  }

  /* Seek documented commands for which zPattern is an exact prefix */
  zPat = sqlite3_mprintf(".%s*", zPattern[0]=='.' ? &zPattern[1] : zPattern);
  shell_check_oom(zPat);
  for(i=0; i<ArraySize(azHelp); i++){
    if( sqlite3_strglob(zPat, azHelp[i])==0 ){
      if( zHit ) cli_printf(out, "%s\n", zHit);
      zHit = azHelp[i];
      j = i+1;
      n++;
    }
  }
  if( n ){
    if( n==1 ){
      const char *zUsage = findUsage(zPat);
      if( zUsage ){
        cli_puts(zUsage, out);
      }else{
        /* when zPattern is a prefix of exactly one command, then include
        ** the details of that command, which should begin at offset j */
        cli_printf(out, "%s\n", zHit);
        while( j<ArraySize(azHelp)-1 && azHelp[j][0]==' ' ){
          cli_printf(out, "%s\n", azHelp[j]);
          j++;
        }
      }
    }else{
      cli_printf(out, "%s\n", zHit);
    }
  }
  sqlite3_free(zPat);
  if( n ) return n;

  /* Look for documented commands that contain zPattern anywhere.
  ** Show complete text of all documented commands that match. */
  zPat = sqlite3_mprintf("%%%s%%", zPattern);
  shell_check_oom(zPat);
  for(i=0; i<ArraySize(azHelp); i++){
    if( azHelp[i][0]==',' ){
      while( i<ArraySize(azHelp)-1 && azHelp[i+1][0]==' ' ) ++i;
      continue;
    }
    if( azHelp[i][0]=='.' ) j = i;
    if( sqlite3_strlike(zPat, azHelp[i], 0)==0 ){
      cli_printf(out, "%s\n", azHelp[j]);
      while( j<ArraySize(azHelp)-1 && azHelp[j+1][0]==' ' ){
        j++;
        cli_printf(out, "%s\n", azHelp[j]);
      }
      i = j;
      n++;
    }
  }
  sqlite3_free(zPat);
  return n;
}

/* Forward reference */
static int process_input(ShellState *p, const char*);

/*
** Read the content of file zName into memory obtained from sqlite3_malloc64()
** and return a pointer to the buffer. The caller is responsible for freeing
** the memory.
**
** If parameter pnByte is not NULL, (*pnByte) is set to the number of bytes
** read.
**
** For convenience, a nul-terminator byte is always appended to the data read
** from the file before the buffer is returned. This byte is not included in
** the final value of (*pnByte), if applicable.
**
** NULL is returned if any error is encountered. The final value of *pnByte
** is undefined in this case.
*/
static char *readFile(const char *zName, int *pnByte){
  FILE *in = sqlite3_fopen(zName, "rb");
  long nIn;
  size_t nRead;
  char *pBuf;
  int rc;
  if( in==0 ) return 0;
  rc = fseek(in, 0, SEEK_END);
  if( rc!=0 ){
    cli_printf(stderr,"Error: '%s' not seekable\n", zName);
    fclose(in);
    return 0;
  }
  nIn = ftell(in);
  rewind(in);
  pBuf = sqlite3_malloc64( nIn+1 );
  if( pBuf==0 ){
    cli_puts("Error: out of memory\n", stderr);
    fclose(in);
    return 0;
  }
  nRead = fread(pBuf, nIn, 1, in);
  fclose(in);
  if( nRead!=1 ){
    sqlite3_free(pBuf);
    cli_printf(stderr,"Error: cannot read '%s'\n", zName);
    return 0;
  }
  pBuf[nIn] = 0;
  if( pnByte ) *pnByte = nIn;
  return pBuf;
}

#if defined(SQLITE_ENABLE_SESSION)
/*
** Close a single OpenSession object and release all of its associated
** resources.
*/
static void session_close(OpenSession *pSession){
  int i;
  sqlite3session_delete(pSession->p);
  sqlite3_free(pSession->zName);
  for(i=0; i<pSession->nFilter; i++){
    sqlite3_free(pSession->azFilter[i]);
  }
  sqlite3_free(pSession->azFilter);
  memset(pSession, 0, sizeof(OpenSession));
}
#endif

/*
** Close all OpenSession objects and release all associated resources.
*/
#if defined(SQLITE_ENABLE_SESSION)
static void session_close_all(ShellState *p, int i){
  int j;
  struct AuxDb *pAuxDb = i<0 ? p->pAuxDb : &p->aAuxDb[i];
  for(j=0; j<pAuxDb->nSession; j++){
    session_close(&pAuxDb->aSession[j]);
  }
  pAuxDb->nSession = 0;
}
#else
# define session_close_all(X,Y)
#endif

/*
** Implementation of the xFilter function for an open session.  Omit
** any tables named by ".session filter" but let all other table through.
*/
#if defined(SQLITE_ENABLE_SESSION)
static int session_filter(void *pCtx, const char *zTab){
  OpenSession *pSession = (OpenSession*)pCtx;
  int i;
  for(i=0; i<pSession->nFilter; i++){
    if( sqlite3_strglob(pSession->azFilter[i], zTab)==0 ) return 0;
  }
  return 1;
}
#endif

/*
** Return the size of the named file in bytes.  Or return a negative
** number if the file does not exist.
*/
static sqlite3_int64 fileSize(const char *zFile){
#if defined(_WIN32) || defined(WIN32)
  struct _stat64 x;
  if( _stat64(zFile, &x)!=0 ) return -1;
  return (sqlite3_int64)x.st_size;
#else
  struct stat x;
  if( stat(zFile, &x)!=0 ) return -1;
  return (sqlite3_int64)x.st_size;
#endif
}

/*
** Return true if zFile is an SQLite database.
**
** Algorithm:
**    * If the file does not exist -> return false
**    * If the size of the file is not a multiple of 512 -> return false
**    * If sqlite3_open() fails -> return false
**    * if sqlite3_prepare() or sqlite3_step() fails -> return false
**    * Otherwise -> return true
*/
static int isDatabaseFile(const char *zFile, int openFlags){
  sqlite3 *db = 0;
  sqlite3_stmt *pStmt = 0;
  int rc;
  sqlite3_int64 sz = fileSize(zFile);
  if( sz<512 || (sz%512)!=0 ) return 0;
  if( sqlite3_open_v2(zFile, &db, openFlags, 0)==SQLITE_OK
   && sqlite3_prepare_v2(db,"SELECT count(*) FROM sqlite_schema",-1,&pStmt,0)
           ==SQLITE_OK
   && sqlite3_step(pStmt)==SQLITE_ROW
  ){
    rc = 1;
  }else{
    rc = 0;
  }
  sqlite3_finalize(pStmt);
  sqlite3_close(db);
  return rc;
}

/*
** Try to deduce the type of file for zName based on its content.  Return
** one of the SHELL_OPEN_* constants.
**
** If the file does not exist or is empty but its name looks like a ZIP
** archive and the dfltZip flag is true, then assume it is a ZIP archive.
** Otherwise, assume an ordinary database regardless of the filename if
** the type cannot be determined from content.
*/
int deduceDatabaseType(const char *zName, int dfltZip, int openFlags){
  FILE *f;
  size_t n;
  int rc = SHELL_OPEN_UNSPEC;
  char zBuf[100];
  if( access(zName,0)!=0 ) goto database_type_by_name;
  if( isDatabaseFile(zName, openFlags) ){
    rc = SHELL_OPEN_NORMAL;
  }
  if( rc==SHELL_OPEN_NORMAL ) return SHELL_OPEN_NORMAL;
  f = sqlite3_fopen(zName, "rb");
  if( f==0 ) goto database_type_by_name;
  n = fread(zBuf, 16, 1, f);
  if( n==1 && memcmp(zBuf, "SQLite format 3", 16)==0 ){
    fclose(f);
    return SHELL_OPEN_NORMAL;
  }
  fseek(f, -25, SEEK_END);
  n = fread(zBuf, 25, 1, f);
  if( n==1 && memcmp(zBuf, "Start-Of-SQLite3-", 17)==0 ){
    rc = SHELL_OPEN_APPENDVFS;
  }else{
    fseek(f, -22, SEEK_END);
    n = fread(zBuf, 22, 1, f);
    if( n==1 && zBuf[0]==0x50 && zBuf[1]==0x4b && zBuf[2]==0x05
       && zBuf[3]==0x06 ){
      rc = SHELL_OPEN_ZIPFILE;
    }else if( n==0 && dfltZip && sqlite3_strlike("%.zip",zName,0)==0 ){
      rc = SHELL_OPEN_ZIPFILE;
    }
  }
  fclose(f);
  return rc;

database_type_by_name:
  if( dfltZip && sqlite3_strlike("%.zip",zName,0)==0 ){
    rc = SHELL_OPEN_ZIPFILE;
  }else{
    rc = SHELL_OPEN_NORMAL;
  }
  return rc;
}

/*
** If the text in z[] is the name of a readable file and that file appears
** to contain SQL text and/or dot-commands, then return true.  If z[] is
** not a file, or if the file is unreadable, or if the file is a database
** or anything else that is not SQL text and dot-commands, then return false.
**
** If the bLeaveUninit flag is set, then be sure to leave SQLite in an
** uninitialized state.  This means invoking sqlite3_shutdown() after any
** SQLite API is used.
**
** Some amount of guesswork is involved in this decision.
*/
static int isScriptFile(const char *z, int bLeaveUninit){
  sqlite3_int64 sz = fileSize(z);
  if( sz<=0 ) return 0;
  if( (sz%512)==0 ){
    int rc;
    sqlite3_initialize();
    rc = isDatabaseFile(z, SQLITE_OPEN_READONLY);
    if( bLeaveUninit ){
      sqlite3_shutdown();
    }
    if( rc ) return 0;  /* Is a database */
  }
  if( sqlite3_strlike("%.sql",z,0)==0 ) return 1;
  if( sqlite3_strlike("%.txt",z,0)==0 ) return 1;
  return 0;
}

#ifndef SQLITE_OMIT_DESERIALIZE
/*
** Reconstruct an in-memory database using the output from the "dbtotxt"
** program.  Read content from the file in p->aAuxDb[].zDbFilename.
** If p->aAuxDb[].zDbFilename is 0, then read from standard input.
*/
static unsigned char *readHexDb(ShellState *p, int *pnData){
  unsigned char *a = 0;
  i64 nLine;
  int n = 0;                      /* Size of db per first line of hex dump */
  i64 sz = 0;                     /* n rounded up to nearest page boundary */
  int pgsz = 0;
  i64 iOffset = 0;
  int rc;
  FILE *in;
  const char *zDbFilename = p->pAuxDb->zDbFilename;
  unsigned int x[16];
  char zLine[1000];
  if( zDbFilename ){
    in = sqlite3_fopen(zDbFilename, "r");
    if( in==0 ){
      cli_printf(stderr,"cannot open \"%s\" for reading\n", zDbFilename);
      return 0;
    }
    nLine = 0;
  }else{
    in = p->in;
    nLine = p->lineno;
    if( in==0 ) in = stdin;
  }
  *pnData = 0;
  nLine++;
  if( sqlite3_fgets(zLine, sizeof(zLine), in)==0 ) goto readHexDb_error;
  rc = sscanf(zLine, "| size %d pagesize %d", &n, &pgsz);
  if( rc!=2 ) goto readHexDb_error;
  if( n<0 ) goto readHexDb_error;
  if( pgsz<512 || pgsz>65536 || (pgsz & (pgsz-1))!=0 ){
    cli_puts("invalid pagesize\n", stderr);
    goto readHexDb_error;
  }
  sz = ((i64)n+pgsz-1)&~(pgsz-1); /* Round up to nearest multiple of pgsz */
  a = sqlite3_malloc64( sz ? sz : 1 );
  shell_check_oom(a);
  memset(a, 0, sz);
  for(nLine++; sqlite3_fgets(zLine, sizeof(zLine), in)!=0; nLine++){
    int j = 0;                    /* Page number from "| page" line */
    int k = 0;                    /* Offset from "| page" line */
    if( nLine>=2000000000 ){
      cli_printf(stderr, "input too big\n");
      goto readHexDb_error;
    }
    rc = sscanf(zLine, "| page %d offset %d", &j, &k);
    if( rc==2 ){
      iOffset = k;
      continue;
    }
    if( cli_strncmp(zLine, "| end ", 6)==0 ){
      break;
    }
    rc = sscanf(zLine,"| %d: %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x",
                &j, &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
                &x[8], &x[9], &x[10], &x[11], &x[12], &x[13], &x[14], &x[15]);
    if( rc==17 ){
      i64 iOff = iOffset+j;
      if( iOff+16<=sz && iOff>=0 ){
        int ii;
        for(ii=0; ii<16; ii++) a[iOff+ii] = x[ii]&0xff;
      }
    }
  }
  *pnData = sz;
  if( in!=p->in ){
    fclose(in);
  }else{
    p->lineno = nLine;
  }
  return a;

readHexDb_error:
  if( in!=p->in ){
    fclose(in);
  }else{
    while( sqlite3_fgets(zLine, sizeof(zLine), p->in)!=0 ){
      nLine++;
      if(cli_strncmp(zLine, "| end ", 6)==0 ) break;
    }
    p->lineno = nLine;
  }
  sqlite3_free(a);
  cli_printf(stderr,"Error on line %lld of --hexdb input\n", nLine);
  return 0;
}
#endif /* SQLITE_OMIT_DESERIALIZE */

/*
** Scalar function "usleep(X)" invokes sqlite3_sleep(X) and returns X.
*/
static void shellUSleepFunc(
  sqlite3_context *context,
  int argcUnused,
  sqlite3_value **argv
){
  int sleep = sqlite3_value_int(argv[0]);
  (void)argcUnused;
  sqlite3_sleep(sleep/1000);
  sqlite3_result_int(context, sleep);
}

/*
** SQL function:  shell_module_schema(X)
**
** Return a fake schema for the table-valued function or eponymous virtual
** table X.
*/
static void shellModuleSchema(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  const char *zName;
  char *zFake;
  ShellState *p = (ShellState*)sqlite3_user_data(pCtx);
  FILE *pSavedLog = p->pLog;
  UNUSED_PARAMETER(nVal);
  zName = (const char*)sqlite3_value_text(apVal[0]);

  /* Temporarily disable the ".log" when calling shellFakeSchema() because
  ** shellFakeSchema() might generate failures for some ephemeral virtual
  ** tables due to missing arguments.  Example: fts4aux.
  ** https://sqlite.org/forum/forumpost/42fe6520b803be51 */
  p->pLog = 0;
  zFake = zName? shellFakeSchema(sqlite3_context_db_handle(pCtx), 0, zName) : 0;
  p->pLog = pSavedLog;

  if( zFake ){
    sqlite3_result_text(pCtx, sqlite3_mprintf("/* %s */", zFake),
                        -1, sqlite3_free);
    sqlite3_free(zFake);
  }
}

/* Flags for open_db().
**
** The default behavior of open_db() is to exit(1) if the database fails to
** open.  The OPEN_DB_KEEPALIVE flag changes that so that it prints an error
** but still returns without calling exit.
**
** The OPEN_DB_ZIPFILE flag causes open_db() to prefer to open files as a
** ZIP archive if the file does not exist or is empty and its name matches
** the *.zip pattern.
*/
#define OPEN_DB_KEEPALIVE   0x001   /* Return after error if true */
#define OPEN_DB_ZIPFILE     0x002   /* Open as ZIP if name matches *.zip */

/*
** Make sure the database is open.  If it is not, then open it.  If
** the database fails to open, print an error message and exit.
*/
static void open_db(ShellState *p, int openFlags){
  if( p->db==0 ){
    const char *zDbFilename = p->pAuxDb->zDbFilename;
    if( p->openMode==SHELL_OPEN_UNSPEC ){
      if( zDbFilename==0 || zDbFilename[0]==0 ){
        p->openMode = SHELL_OPEN_NORMAL;
      }else{
        p->openMode = (u8)deduceDatabaseType(zDbFilename,
                             (openFlags & OPEN_DB_ZIPFILE)!=0, p->openFlags);
      }
    }
    if( (p->openFlags & (SQLITE_OPEN_READONLY|SQLITE_OPEN_READWRITE))==0 ){
      if( p->openFlags==0 ) p->openFlags = SQLITE_OPEN_CREATE;
      p->openFlags |= SQLITE_OPEN_READWRITE;
    }
    switch( p->openMode ){
      case SHELL_OPEN_APPENDVFS: {
        sqlite3_open_v2(zDbFilename, &p->db, p->openFlags, "apndvfs");
        break;
      }
      case SHELL_OPEN_HEXDB:
      case SHELL_OPEN_DESERIALIZE: {
        sqlite3_open(0, &p->db);
        break;
      }
      case SHELL_OPEN_ZIPFILE: {
        sqlite3_open(":memory:", &p->db);
        break;
      }
      case SHELL_OPEN_UNSPEC:
      case SHELL_OPEN_NORMAL: {
        sqlite3_open_v2(zDbFilename, &p->db, p->openFlags, 0);
        break;
      }
    }
    if( p->db==0 || SQLITE_OK!=sqlite3_errcode(p->db) ){
      cli_printf(stderr,"Error: unable to open database \"%s\": %s\n",
            zDbFilename, sqlite3_errmsg(p->db));
      if( (openFlags & OPEN_DB_KEEPALIVE)==0 ){
        cli_exit(1);
      }
      sqlite3_close(p->db);
      sqlite3_open(":memory:", &p->db);
      if( p->db==0 || SQLITE_OK!=sqlite3_errcode(p->db) ){
        cli_puts("Also: unable to open substitute in-memory database.\n",
                      stderr);
        cli_exit(1);
      }else{
        cli_printf(stderr,
              "Notice: using substitute in-memory database instead of \"%s\"\n",
              zDbFilename);
      }
    }
    globalDb = p->db;
    sqlite3_db_config(p->db, SQLITE_DBCONFIG_STMT_SCANSTATUS, (int)0, (int*)0);

    /* Reflect the use or absence of --unsafe-testing invocation. */
    {
      int testmode_on = ShellHasFlag(p,SHFLG_TestingMode);
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_TRUSTED_SCHEMA, testmode_on,0);
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, !testmode_on,0);
    }

#ifndef SQLITE_OMIT_LOAD_EXTENSION
    sqlite3_enable_load_extension(p->db, 1);
#endif
    sqlite3_sha_init(p->db, 0, 0);
    sqlite3_shathree_init(p->db, 0, 0);
    sqlite3_uint_init(p->db, 0, 0);
    sqlite3_stmtrand_init(p->db, 0, 0);
    sqlite3_decimal_init(p->db, 0, 0);
    sqlite3_base64_init(p->db, 0, 0);
    sqlite3_base85_init(p->db, 0, 0);
    sqlite3_regexp_init(p->db, 0, 0);
    sqlite3_ieee_init(p->db, 0, 0);
    sqlite3_series_init(p->db, 0, 0);
#ifndef SQLITE_SHELL_FIDDLE
    sqlite3_fileio_init(p->db, 0, 0);
    sqlite3_completion_init(p->db, 0, 0);
#endif
#ifdef SQLITE_HAVE_ZLIB
    if( !p->bSafeModePersist ){
      sqlite3_zipfile_init(p->db, 0, 0);
      sqlite3_sqlar_init(p->db, 0, 0);
    }
#endif
#ifdef SQLITE_SHELL_EXTFUNCS
    /* Create a preprocessing mechanism for extensions to make
     * their own provisions for being built into the shell.
     * This is a short-span macro. See further below for usage.
     */
#define SHELL_SUB_MACRO(base, variant) base ## _ ## variant
#define SHELL_SUBMACRO(base, variant) SHELL_SUB_MACRO(base, variant)
    /* Let custom-included extensions get their ..._init() called.
     * The WHATEVER_INIT( db, pzErrorMsg, pApi ) macro should cause
     * the extension's sqlite3_*_init( db, pzErrorMsg, pApi )
     * initialization routine to be called.
     */
    {
      int irc = SHELL_SUBMACRO(SQLITE_SHELL_EXTFUNCS, INIT)(p->db);
    /* Let custom-included extensions expose their functionality.
     * The WHATEVER_EXPOSE( db, pzErrorMsg ) macro should cause
     * the SQL functions, virtual tables, collating sequences or
     * VFS's implemented by the extension to be registered.
     */
      if( irc==SQLITE_OK
          || irc==SQLITE_OK_LOAD_PERMANENTLY ){
        SHELL_SUBMACRO(SQLITE_SHELL_EXTFUNCS, EXPOSE)(p->db, 0);
      }
#undef SHELL_SUB_MACRO
#undef SHELL_SUBMACRO
    }
#endif

    sqlite3_create_function(p->db, "strtod", 1, SQLITE_UTF8, 0,
                            shellStrtod, 0, 0);
    sqlite3_create_function(p->db, "dtostr", 1, SQLITE_UTF8, 0,
                            shellDtostr, 0, 0);
    sqlite3_create_function(p->db, "dtostr", 2, SQLITE_UTF8, 0,
                            shellDtostr, 0, 0);
    sqlite3_create_function(p->db, "shell_add_schema", 3, SQLITE_UTF8, 0,
                            shellAddSchemaName, 0, 0);
    sqlite3_create_function(p->db, "shell_module_schema", 1, SQLITE_UTF8, p,
                            shellModuleSchema, 0, 0);
    sqlite3_create_function(p->db, "shell_putsnl", 1, SQLITE_UTF8, p,
                            shellPutsFunc, 0, 0);
    sqlite3_create_function(p->db, "shell_format_schema", 2, SQLITE_UTF8, p,
                            shellFormatSchema, 0, 0);
    sqlite3_create_function(p->db, "usleep",1,SQLITE_UTF8,0,
                            shellUSleepFunc, 0, 0);
#ifndef SQLITE_NOHAVE_SYSTEM
    sqlite3_create_function(p->db, "edit", 1, SQLITE_UTF8, 0,
                            editFunc, 0, 0);
    sqlite3_create_function(p->db, "edit", 2, SQLITE_UTF8, 0,
                            editFunc, 0, 0);
#endif

    if( p->openMode==SHELL_OPEN_ZIPFILE ){
      char *zSql = sqlite3_mprintf(
         "CREATE VIRTUAL TABLE zip USING zipfile(%Q);", zDbFilename);
      shell_check_oom(zSql);
      sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_free(zSql);
    }
#ifndef SQLITE_OMIT_DESERIALIZE
    else
    if( p->openMode==SHELL_OPEN_DESERIALIZE || p->openMode==SHELL_OPEN_HEXDB ){
      int rc;
      int nData = 0;
      unsigned char *aData;
      if( p->openMode==SHELL_OPEN_DESERIALIZE ){
        aData = (unsigned char*)readFile(zDbFilename, &nData);
      }else{
        aData = readHexDb(p, &nData);
      }
      if( aData==0 ){
        return;
      }
      rc = sqlite3_deserialize(p->db, "main", aData, nData, nData,
                   SQLITE_DESERIALIZE_RESIZEABLE |
                   SQLITE_DESERIALIZE_FREEONCLOSE);
      if( rc ){
        cli_printf(stderr,"Error: sqlite3_deserialize() returns %d\n", rc);
      }
      if( p->szMax>0 ){
        sqlite3_file_control(p->db, "main", SQLITE_FCNTL_SIZE_LIMIT, &p->szMax);
      }
    }
#endif
  }
  if( p->db!=0 ){
#ifndef SQLITE_OMIT_AUTHORIZATION
    if( p->bSafeModePersist ){
      sqlite3_set_authorizer(p->db, safeModeAuth, p);
    }
#endif
    sqlite3_db_config(
        p->db, SQLITE_DBCONFIG_STMT_SCANSTATUS, p->mode.scanstatsOn, (int*)0
    );
  }
}

/*
** Attempt to close the database connection.  Report errors.
*/
void close_db(sqlite3 *db){
  int rc = sqlite3_close(db);
  if( rc ){
    cli_printf(stderr,
        "Error: sqlite3_close() returns %d: %s\n", rc, sqlite3_errmsg(db));
  }
}

#if (HAVE_READLINE || HAVE_EDITLINE) \
  && !defined(SQLITE_OMIT_READLINE_COMPLETION)
/*
** Readline completion callbacks
*/
static char *readline_completion_generator(const char *text, int state){
  static sqlite3_stmt *pStmt = 0;
  char *zRet;
  if( state==0 ){
    char *zSql;
    sqlite3_finalize(pStmt);
    zSql = sqlite3_mprintf("SELECT DISTINCT candidate COLLATE nocase"
                           "  FROM completion(%Q) ORDER BY 1", text);
    shell_check_oom(zSql);
    sqlite3_prepare_v2(globalDb, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
  }
  if( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *z = (const char*)sqlite3_column_text(pStmt,0);
    zRet = z ? strdup(z) : 0;
  }else{
    sqlite3_finalize(pStmt);
    pStmt = 0;
    zRet = 0;
  }
  return zRet;
}
static char **readline_completion(const char *zText, int iStart, int iEnd){
  (void)iStart;
  (void)iEnd;
  rl_attempted_completion_over = 1;
  return rl_completion_matches(zText, readline_completion_generator);
}

#elif HAVE_LINENOISE
/*
** Linenoise completion callback. Note that the 3rd argument is from
** the "msteveb" version of linenoise, not the "antirez" version.
*/
static void linenoise_completion(
  const char *zLine,
  linenoiseCompletions *lc
#if HAVE_LINENOISE==2
  ,void *pUserData
#endif
){
  i64 nLine = strlen(zLine);
  i64 i, iStart;
  sqlite3_stmt *pStmt = 0;
  char *zSql;
  char zBuf[1000];

#if HAVE_LINENOISE==2
  UNUSED_PARAMETER(pUserData);
#endif
  if( nLine>(i64)sizeof(zBuf)-30 ) return;
  if( zLine[0]=='.' || zLine[0]=='#') return;
  for(i=nLine-1; i>=0 && (IsAlnum(zLine[i]) || zLine[i]=='_'); i--){}
  if( i==nLine-1 ) return;
  iStart = i+1;
  memcpy(zBuf, zLine, iStart);
  zSql = sqlite3_mprintf("SELECT DISTINCT candidate COLLATE nocase"
                         "  FROM completion(%Q,%Q) ORDER BY 1",
                         &zLine[iStart], zLine);
  shell_check_oom(zSql);
  sqlite3_prepare_v2(globalDb, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  sqlite3_exec(globalDb, "PRAGMA page_count", 0, 0, 0); /* Load the schema */
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *zCompletion = (const char*)sqlite3_column_text(pStmt, 0);
    int nCompletion = sqlite3_column_bytes(pStmt, 0);
    if( iStart+nCompletion < (i64)sizeof(zBuf)-1 && zCompletion ){
      memcpy(zBuf+iStart, zCompletion, nCompletion+1);
      linenoiseAddCompletion(lc, zBuf);
    }
  }
  sqlite3_finalize(pStmt);
}
#endif

/*
** Do C-language style dequoting.
**
**    \a    -> alarm
**    \b    -> backspace
**    \t    -> tab
**    \n    -> newline
**    \v    -> vertical tab
**    \f    -> form feed
**    \r    -> carriage return
**    \s    -> space
**    \"    -> "
**    \'    -> '
**    \\    -> backslash
**    \NNN  -> ascii character NNN in octal
**    \xHH  -> ascii character HH in hexadecimal
*/
static void resolve_backslashes(char *z){
  int i, j;
  char c;
  while( *z && *z!='\\' ) z++;
  for(i=j=0; (c = z[i])!=0; i++, j++){
    if( c=='\\' && z[i+1]!=0 ){
      c = z[++i];
      if( c=='a' ){
        c = '\a';
      }else if( c=='b' ){
        c = '\b';
      }else if( c=='t' ){
        c = '\t';
      }else if( c=='n' ){
        c = '\n';
      }else if( c=='v' ){
        c = '\v';
      }else if( c=='f' ){
        c = '\f';
      }else if( c=='r' ){
        c = '\r';
      }else if( c=='"' ){
        c = '"';
      }else if( c=='\'' ){
        c = '\'';
      }else if( c=='\\' ){
        c = '\\';
      }else if( c=='x' ){
        int nhd = 0, hdv;
        u8 hv = 0;
        while( nhd<2 && (c=z[i+1+nhd])!=0 && (hdv=hexDigitValue(c))>=0 ){
          hv = (u8)((hv<<4)|hdv);
          ++nhd;
        }
        i += nhd;
        c = (u8)hv;
      }else if( c>='0' && c<='7' ){
        c -= '0';
        if( z[i+1]>='0' && z[i+1]<='7' ){
          i++;
          c = (c<<3) + z[i] - '0';
          if( z[i+1]>='0' && z[i+1]<='7' ){
            i++;
            c = (c<<3) + z[i] - '0';
          }
        }
      }
    }
    z[j] = c;
  }
  if( j<i ) z[j] = 0;
}

/*
** Interpret zArg as either an integer or a boolean value.  Return 1 or 0
** for TRUE and FALSE.  Return the integer value if appropriate.
*/
static int booleanValue(const char *zArg){
  int i;
  if( zArg[0]=='0' && zArg[1]=='x' ){
    for(i=2; hexDigitValue(zArg[i])>=0; i++){}
  }else{
    for(i=0; zArg[i]>='0' && zArg[i]<='9'; i++){}
  }
  if( i>0 && zArg[i]==0 ) return (int)(integerValue(zArg) & 0xffffffff);
  if( sqlite3_stricmp(zArg, "on")==0 || sqlite3_stricmp(zArg,"yes")==0 ){
    return 1;
  }
  if( sqlite3_stricmp(zArg, "off")==0 || sqlite3_stricmp(zArg,"no")==0 ){
    return 0;
  }
  cli_printf(stderr,
       "ERROR: Not a boolean value: \"%s\". Assuming \"no\".\n", zArg);
  return 0;
}

/*
** Set or clear a shell flag according to a boolean value.
*/
static void setOrClearFlag(ShellState *p, unsigned mFlag, const char *zArg){
  if( booleanValue(zArg) ){
    ShellSetFlag(p, mFlag);
  }else{
    ShellClearFlag(p, mFlag);
  }
}

/*
** Close an output file, assuming it is not stderr or stdout
*/
static void output_file_close(FILE *f){
  if( f && f!=stdout && f!=stderr ) fclose(f);
}

/*
** Try to open an output file.   The names "stdout" and "stderr" are
** recognized and do the right thing.  NULL is returned if the output
** filename is "off".
*/
static FILE *output_file_open(ShellState *p, const char *zFile){
  FILE *f;
  if( cli_strcmp(zFile,"stdout")==0 ){
    f = stdout;
  }else if( cli_strcmp(zFile, "stderr")==0 ){
    f = stderr;
  }else if( cli_strcmp(zFile, "off")==0 || p->bSafeMode ){
    f = 0;
  }else{
    f = sqlite3_fopen(zFile, "w");
    if( f==0 ){
      cli_printf(stderr,"Error: cannot open \"%s\"\n", zFile);
    }
  }
  return f;
}

#ifndef SQLITE_OMIT_TRACE
/*
** A routine for handling output from sqlite3_trace().
*/
static int sql_trace_callback(
  unsigned mType,         /* The trace type */
  void *pArg,             /* The ShellState pointer */
  void *pP,               /* Usually a pointer to sqlite_stmt */
  void *pX                /* Auxiliary output */
){
  ShellState *p = (ShellState*)pArg;
  sqlite3_stmt *pStmt;
  const char *zSql;
  i64 nSql;
  if( p->traceOut==0 ) return 0;
  if( mType==SQLITE_TRACE_CLOSE ){
    sputz(p->traceOut, "-- closing database connection\n");
    return 0;
  }
  if( mType!=SQLITE_TRACE_ROW && pX!=0 && ((const char*)pX)[0]=='-' ){
    zSql = (const char*)pX;
  }else{
    pStmt = (sqlite3_stmt*)pP;
    switch( p->eTraceType ){
      case SHELL_TRACE_EXPANDED: {
        zSql = sqlite3_expanded_sql(pStmt);
        break;
      }
#ifdef SQLITE_ENABLE_NORMALIZE
      case SHELL_TRACE_NORMALIZED: {
        zSql = sqlite3_normalized_sql(pStmt);
        break;
      }
#endif
      default: {
        zSql = sqlite3_sql(pStmt);
        break;
      }
    }
  }
  if( zSql==0 ) return 0;
  nSql = strlen(zSql);
  if( nSql>1000000000 ) nSql = 1000000000;
  while( nSql>0 && zSql[nSql-1]==';' ){ nSql--; }
  switch( mType ){
    case SQLITE_TRACE_ROW:
    case SQLITE_TRACE_STMT: {
      cli_printf(p->traceOut, "%.*s;\n", (int)nSql, zSql);
      break;
    }
    case SQLITE_TRACE_PROFILE: {
      sqlite3_int64 nNanosec = pX ? *(sqlite3_int64*)pX : 0;
      cli_printf(p->traceOut,
                      "%.*s; -- %lld ns\n", (int)nSql, zSql, nNanosec);
      break;
    }
  }
  return 0;
}
#endif

/*
** A no-op routine that runs with the ".breakpoint" doc-command.  This is
** a useful spot to set a debugger breakpoint.
**
** This routine does not do anything practical.  The code are there simply
** to prevent the compiler from optimizing this routine out.
*/
static void test_breakpoint(void){
  static unsigned int nCall = 0;
  if( (nCall++)==0xffffffff ) printf("Many .breakpoints have run\n");
}

/*
** An object used to read a CSV and other files for import.
*/
typedef struct ImportCtx ImportCtx;
struct ImportCtx {
  const char *zFile;  /* Name of the input file */
  FILE *in;           /* Read the CSV text from this input stream */
  int (SQLITE_CDECL *xCloser)(FILE*);      /* Func to close in */
  char *zIn;          /* Input text */
  char *z;            /* Accumulated text for a field */
  i64 nUsed;          /* Bytes of zIn[] used so far */
  i64 n;              /* Number of bytes in z */
  i64 nAlloc;         /* Space allocated for z[] */
  int nLine;          /* Current line number */
  int nRow;           /* Number of rows imported */
  int nErr;           /* Number of errors encountered */
  int bNotFirst;      /* True if one or more bytes already read */
  int cTerm;          /* Character that terminated the most recent field */
  int cColSep;        /* The column separator character.  (Usually ",") */
  int cRowSep;        /* The row separator character.  (Usually "\n") */
  int cQEscape;       /* Escape character with "...".  0 for none */
  int cUQEscape;      /* Escape character not with "...".  0 for none */
};

/* Clean up resourced used by an ImportCtx */
static void import_cleanup(ImportCtx *p){
  if( p->in!=0 && p->xCloser!=0 ){
    p->xCloser(p->in);
    p->in = 0;
  }
  sqlite3_free(p->z);
  p->z = 0;
  if( p->zIn ){
    sqlite3_free(p->zIn);
    p->zIn = 0;
  }
}

/* Read a single character of the .import input text.  Return EOF
** at end-of-file.
*/
static int import_getc(ImportCtx *p){
  if( p->in ){
    return fgetc(p->in);
  }else if( p->zIn && p->zIn[p->nUsed]!=0 ){
    return p->zIn[p->nUsed++];
  }else{
    return EOF;
  }
}

/* Append a single byte to the field value begin constructed
** in the p->z[] buffer
*/
static void import_append_char(ImportCtx *p, int c){
  if( p->n+1>=p->nAlloc ){
    p->nAlloc += p->nAlloc + 100;
    p->z = sqlite3_realloc64(p->z, p->nAlloc);
    shell_check_oom(p->z);
  }
  p->z[p->n++] = (char)c;
}

/* Read a single field of CSV text.  Compatible with rfc4180 and extended
** with the option of having a separator other than ",".
**
**   +  Input comes from p->in.
**   +  Store results in p->z of length p->n.  Space to hold p->z comes
**      from sqlite3_malloc64().
**   +  Use p->cColSep as the column separator.  The default is ",".
**   +  Use p->cRowSep as the row separator.  The default is "\n".
**   +  Keep track of the line number in p->nLine.
**   +  Store the character that terminates the field in p->cTerm.  Store
**      EOF on end-of-file.
**   +  Report syntax errors on stderr
*/
static char *SQLITE_CDECL csv_read_one_field(ImportCtx *p){
  int c;
  int cSep = (u8)p->cColSep;
  int rSep = (u8)p->cRowSep;
  p->n = 0;
  c = import_getc(p);
  if( c==EOF || seenInterrupt ){
    p->cTerm = EOF;
    return 0;
  }
  if( c=='"' ){
    int pc, ppc;
    int startLine = p->nLine;
    int cQuote = c;
    int cEsc = (u8)p->cQEscape;
    pc = ppc = 0;
    while( 1 ){
      c = import_getc(p);
      if( c==rSep ) p->nLine++;
      if( c==cEsc && cEsc!=0 ){
        c = import_getc(p);
        import_append_char(p, c);
        ppc = pc = 0;
        continue;
      }
      if( c==cQuote ){
        if( pc==cQuote ){
          pc = 0;
          continue;
        }
      }
      if( (c==cSep && pc==cQuote)
       || (c==rSep && pc==cQuote)
       || (c==rSep && pc=='\r' && ppc==cQuote)
       || (c==EOF && pc==cQuote)
      ){
        do{ p->n--; }while( p->z[p->n]!=cQuote );
        p->cTerm = c;
        break;
      }
      if( pc==cQuote && c!='\r' ){
        cli_printf(stderr,"%s:%d: unescaped %c character\n", 
                   p->zFile, p->nLine, cQuote);
      }
      if( c==EOF ){
        cli_printf(stderr,"%s:%d: unterminated %c-quoted field\n",
              p->zFile, startLine, cQuote);
        p->cTerm = c;
        break;
      }
      import_append_char(p, c);
      ppc = pc;
      pc = c;
    }
  }else{
    /* If this is the first field being parsed and it begins with the
    ** UTF-8 BOM  (0xEF BB BF) then skip the BOM */
    int cEsc = p->cUQEscape;
    if( (c&0xff)==0xef && p->bNotFirst==0 ){
      import_append_char(p, c);
      c = import_getc(p);
      if( (c&0xff)==0xbb ){
        import_append_char(p, c);
        c = import_getc(p);
        if( (c&0xff)==0xbf ){
          p->bNotFirst = 1;
          p->n = 0;
          return csv_read_one_field(p);
        }
      }
    }
    while( c!=EOF && c!=cSep && c!=rSep ){
      if( c==cEsc && cEsc!=0 ) c = import_getc(p);
      import_append_char(p, c);
      c = import_getc(p);
    }
    if( c==rSep ){
      p->nLine++;
      if( p->n>0 && p->z[p->n-1]=='\r' ) p->n--;
    }
    p->cTerm = c;
  }
  if( p->z ) p->z[p->n] = 0;
  p->bNotFirst = 1;
  return p->z;
}

/* Read a single field of ASCII delimited text.
**
**   +  Input comes from p->in.
**   +  Store results in p->z of length p->n.  Space to hold p->z comes
**      from sqlite3_malloc64().
**   +  Use p->cColSep as the column separator.  The default is "\x1F".
**   +  Use p->cRowSep as the row separator.  The default is "\x1E".
**   +  Keep track of the row number in p->nLine.
**   +  Store the character that terminates the field in p->cTerm.  Store
**      EOF on end-of-file.
**   +  Report syntax errors on stderr
*/
static char *SQLITE_CDECL ascii_read_one_field(ImportCtx *p){
  int c;
  int cSep = (u8)p->cColSep;
  int rSep = (u8)p->cRowSep;
  p->n = 0;
  c = import_getc(p);
  if( c==EOF || seenInterrupt ){
    p->cTerm = EOF;
    return 0;
  }
  while( c!=EOF && c!=cSep && c!=rSep ){
    import_append_char(p, c);
    c = import_getc(p);
  }
  if( c==rSep ){
    p->nLine++;
  }
  p->cTerm = c;
  if( p->z ) p->z[p->n] = 0;
  return p->z;
}

/*
** Try to transfer data for table zTable.  If an error is seen while
** moving forward, try to go backwards.  The backwards movement won't
** work for WITHOUT ROWID tables.
*/
static void tryToCloneData(
  ShellState *p,
  sqlite3 *newDb,
  const char *zTable
){
  sqlite3_stmt *pQuery = 0;
  sqlite3_stmt *pInsert = 0;
  char *zQuery = 0;
  char *zInsert = 0;
  int rc;
  int i, j, n;
  int nTable = strlen30(zTable);
  int k = 0;
  int cnt = 0;
  const int spinRate = 10000;

  zQuery = sqlite3_mprintf("SELECT * FROM \"%w\"", zTable);
  shell_check_oom(zQuery);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    cli_printf(stderr,"Error %d: %s on [%s]\n",
          sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db), zQuery);
    goto end_data_xfer;
  }
  n = sqlite3_column_count(pQuery);
  zInsert = sqlite3_malloc64(200 + nTable + n*3);
  shell_check_oom(zInsert);
  sqlite3_snprintf(200+nTable,zInsert,
                   "INSERT OR IGNORE INTO \"%s\" VALUES(?", zTable);
  i = strlen30(zInsert);
  for(j=1; j<n; j++){
    memcpy(zInsert+i, ",?", 2);
    i += 2;
  }
  memcpy(zInsert+i, ");", 3);
  rc = sqlite3_prepare_v2(newDb, zInsert, -1, &pInsert, 0);
  if( rc ){
    cli_printf(stderr,"Error %d: %s on [%s]\n",
          sqlite3_extended_errcode(newDb), sqlite3_errmsg(newDb), zInsert);
    goto end_data_xfer;
  }
  for(k=0; k<2; k++){
    while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
      for(i=0; i<n; i++){
        switch( sqlite3_column_type(pQuery, i) ){
          case SQLITE_NULL: {
            sqlite3_bind_null(pInsert, i+1);
            break;
          }
          case SQLITE_INTEGER: {
            sqlite3_bind_int64(pInsert, i+1, sqlite3_column_int64(pQuery,i));
            break;
          }
          case SQLITE_FLOAT: {
            sqlite3_bind_double(pInsert, i+1, sqlite3_column_double(pQuery,i));
            break;
          }
          case SQLITE_TEXT: {
            sqlite3_bind_text(pInsert, i+1,
                             (const char*)sqlite3_column_text(pQuery,i),
                             -1, SQLITE_STATIC);
            break;
          }
          case SQLITE_BLOB: {
            sqlite3_bind_blob(pInsert, i+1, sqlite3_column_blob(pQuery,i),
                                            sqlite3_column_bytes(pQuery,i),
                                            SQLITE_STATIC);
            break;
          }
        }
      } /* End for */
      rc = sqlite3_step(pInsert);
      if( rc!=SQLITE_OK && rc!=SQLITE_ROW && rc!=SQLITE_DONE ){
        cli_printf(stderr,"Error %d: %s\n",
              sqlite3_extended_errcode(newDb), sqlite3_errmsg(newDb));
      }
      sqlite3_reset(pInsert);
      cnt++;
      if( (cnt%spinRate)==0 ){
        printf("%c\b", "|/-\\"[(cnt/spinRate)%4]);
        fflush(stdout);
      }
    } /* End while */
    if( rc==SQLITE_DONE ) break;
    sqlite3_finalize(pQuery);
    sqlite3_free(zQuery);
    zQuery = sqlite3_mprintf("SELECT * FROM \"%w\" ORDER BY rowid DESC;",
                             zTable);
    shell_check_oom(zQuery);
    rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
    if( rc ){
      cli_printf(stderr,"Warning: cannot step \"%s\" backwards", zTable);
      break;
    }
  } /* End for(k=0...) */

end_data_xfer:
  sqlite3_finalize(pQuery);
  sqlite3_finalize(pInsert);
  sqlite3_free(zQuery);
  sqlite3_free(zInsert);
}


/*
** Try to transfer all rows of the schema that match zWhere.  For
** each row, invoke xForEach() on the object defined by that row.
** If an error is encountered while moving forward through the
** sqlite_schema table, try again moving backwards.
*/
static void tryToCloneSchema(
  ShellState *p,
  sqlite3 *newDb,
  const char *zWhere,
  void (*xForEach)(ShellState*,sqlite3*,const char*)
){
  sqlite3_stmt *pQuery = 0;
  char *zQuery = 0;
  int rc;
  const unsigned char *zName;
  const unsigned char *zSql;
  char *zErrMsg = 0;

  zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_schema"
                           " WHERE %s ORDER BY rowid ASC", zWhere);
  shell_check_oom(zQuery);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    cli_printf(stderr,
          "Error: (%d) %s on [%s]\n", sqlite3_extended_errcode(p->db),
          sqlite3_errmsg(p->db), zQuery);
    goto end_schema_xfer;
  }
  while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
    zName = sqlite3_column_text(pQuery, 0);
    zSql = sqlite3_column_text(pQuery, 1);
    if( zName==0 || zSql==0 ) continue;
    if( sqlite3_stricmp((char*)zName, "sqlite_sequence")!=0 ){
      cli_printf(stdout, "%s... ", zName); fflush(stdout);
      sqlite3_exec(newDb, (const char*)zSql, 0, 0, &zErrMsg);
      if( zErrMsg ){
        cli_printf(stderr,"Error: %s\nSQL: [%s]\n", zErrMsg, zSql);
        sqlite3_free(zErrMsg);
        zErrMsg = 0;
      }
    }
    if( xForEach ){
      xForEach(p, newDb, (const char*)zName);
    }
    sputz(stdout, "done\n");
  }
  if( rc!=SQLITE_DONE ){
    sqlite3_finalize(pQuery);
    sqlite3_free(zQuery);
    zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_schema"
                             " WHERE %s ORDER BY rowid DESC", zWhere);
    shell_check_oom(zQuery);
    rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
    if( rc ){
      cli_printf(stderr,"Error: (%d) %s on [%s]\n",
            sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db), zQuery);
      goto end_schema_xfer;
    }
    while( sqlite3_step(pQuery)==SQLITE_ROW ){
      zName = sqlite3_column_text(pQuery, 0);
      zSql = sqlite3_column_text(pQuery, 1);
      if( zName==0 || zSql==0 ) continue;
      if( sqlite3_stricmp((char*)zName, "sqlite_sequence")==0 ) continue;
      cli_printf(stdout, "%s... ", zName); fflush(stdout);
      sqlite3_exec(newDb, (const char*)zSql, 0, 0, &zErrMsg);
      if( zErrMsg ){
        cli_printf(stderr,"Error: %s\nSQL: [%s]\n", zErrMsg, zSql);
        sqlite3_free(zErrMsg);
        zErrMsg = 0;
      }
      if( xForEach ){
        xForEach(p, newDb, (const char*)zName);
      }
      sputz(stdout, "done\n");
    }
  }
end_schema_xfer:
  sqlite3_finalize(pQuery);
  sqlite3_free(zQuery);
}

/*
** Open a new database file named "zNewDb".  Try to recover as much information
** as possible out of the main database (which might be corrupt) and write it
** into zNewDb.
*/
static void tryToClone(ShellState *p, const char *zNewDb){
  int rc;
  sqlite3 *newDb = 0;
  if( access(zNewDb,0)==0 ){
    cli_printf(stderr,"File \"%s\" already exists.\n", zNewDb);
    return;
  }
  rc = sqlite3_open(zNewDb, &newDb);
  if( rc ){
    cli_printf(stderr,
        "Cannot create output database: %s\n", sqlite3_errmsg(newDb));
  }else{
    sqlite3_exec(p->db, "PRAGMA writable_schema=ON;", 0, 0, 0);
    sqlite3_exec(newDb, "BEGIN EXCLUSIVE;", 0, 0, 0);
    tryToCloneSchema(p, newDb, "type='table'", tryToCloneData);
    tryToCloneSchema(p, newDb, "type!='table'", 0);
    sqlite3_exec(newDb, "COMMIT;", 0, 0, 0);
    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
  }
  close_db(newDb);
}

#ifndef SQLITE_SHELL_FIDDLE
/*
** Change the output stream (file or pipe or console) to something else.
*/
static void output_redir(ShellState *p, FILE *pfNew){
  if( p->out != stdout ){
    cli_puts("Output already redirected.\n", stderr);
  }else{
    p->out = pfNew;
    setCrlfMode(p);
    if( p->mode.eMode==MODE_Www ){
      cli_puts(
        "<!DOCTYPE html>\n"
        "<HTML><BODY><PRE>\n",
        p->out
      );
    }
  }
}

/*
** Change the output file back to stdout.
**
** If the p->doXdgOpen flag is set, that means the output was being
** redirected to a temporary file named by p->zTempFile.  In that case,
** launch start/open/xdg-open on that temporary file.
*/
static void output_reset(ShellState *p){
  if( p->outfile[0]=='|' ){
#ifndef SQLITE_OMIT_POPEN
    pclose(p->out);
#endif
  }else{
    if( p->mode.eMode==MODE_Www ){
      cli_puts("</PRE></BODY></HTML>\n", p->out);
    }
    output_file_close(p->out);
#ifndef SQLITE_NOHAVE_SYSTEM
    if( p->doXdgOpen ){
      const char *zXdgOpenCmd =
#if defined(_WIN32)
      "start";
#elif defined(__APPLE__)
      "open";
#else
      "xdg-open";
#endif
      char *zCmd;
      zCmd = sqlite3_mprintf("%s %s", zXdgOpenCmd, p->zTempFile);
      if( system(zCmd) ){
        cli_printf(stderr,"Failed: [%s]\n", zCmd);
      }else{
        /* Give the start/open/xdg-open command some time to get
        ** going before we continue, and potential delete the
        ** p->zTempFile data file out from under it */
        sqlite3_sleep(2000);
      }
      sqlite3_free(zCmd);
      modePop(p);
      p->doXdgOpen = 0;
    }
#endif /* !defined(SQLITE_NOHAVE_SYSTEM) */
  }
  p->outfile[0] = 0;
  p->out = stdout;
  setCrlfMode(p);
  if( cli_output_capture ){
    sqlite3_str_free(cli_output_capture);
    cli_output_capture = 0;
  }
}
#else
# define output_redir(SS,pfO)
# define output_reset(SS)
#endif

/*
** Run an SQL command and return the single integer result.
*/
static int db_int(sqlite3 *db, const char *zSql, ...){
  sqlite3_stmt *pStmt;
  int res = 0;
  char *z;
  va_list ap;
  va_start(ap, zSql);
  z = sqlite3_vmprintf(zSql, ap);
  va_end(ap);
  sqlite3_prepare_v2(db, z, -1, &pStmt, 0);
  if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
    res = sqlite3_column_int(pStmt,0);
  }
  sqlite3_finalize(pStmt);
  sqlite3_free(z);
  return res;
}

#if SQLITE_SHELL_HAVE_RECOVER
/*
** Convert a 2-byte or 4-byte big-endian integer into a native integer
*/
static unsigned int get2byteInt(unsigned char *a){
  return ((unsigned int)a[0]<<8) + (unsigned int)a[1];
}
static unsigned int get4byteInt(unsigned char *a){
  return ((unsigned int)a[0]<<24)
       + ((unsigned int)a[1]<<16)
       + ((unsigned int)a[2]<<8)
       + (unsigned int)a[3];
}

/*
** Implementation of the ".dbinfo" command.
**
** Return 1 on error, 2 to exit, and 0 otherwise.
*/
static int shell_dbinfo_command(ShellState *p, int nArg, char **azArg){
  static const struct { const char *zName; int ofst; } aField[] = {
     { "file change counter:",  24  },
     { "database page count:",  28  },
     { "freelist page count:",  36  },
     { "schema cookie:",        40  },
     { "schema format:",        44  },
     { "default cache size:",   48  },
     { "autovacuum top root:",  52  },
     { "incremental vacuum:",   64  },
     { "text encoding:",        56  },
     { "user version:",         60  },
     { "application id:",       68  },
     { "software version:",     96  },
  };
  static const struct { const char *zName; const char *zSql; } aQuery[] = {
     { "number of tables:",
       "SELECT count(*) FROM %s WHERE type='table'" },
     { "number of indexes:",
       "SELECT count(*) FROM %s WHERE type='index'" },
     { "number of triggers:",
       "SELECT count(*) FROM %s WHERE type='trigger'" },
     { "number of views:",
       "SELECT count(*) FROM %s WHERE type='view'" },
     { "schema size:",
       "SELECT total(length(sql)) FROM %s" },
  };
  int i, rc;
  unsigned iDataVersion;
  char *zSchemaTab;
  char *zDb = nArg>=2 ? azArg[1] : "main";
  sqlite3_stmt *pStmt = 0;
  unsigned char aHdr[100];
  open_db(p, 0);
  if( p->db==0 ) return 1;
  rc = sqlite3_prepare_v2(p->db,
             "SELECT data FROM sqlite_dbpage(?1) WHERE pgno=1",
             -1, &pStmt, 0);
  if( rc ){
    cli_printf(stderr,"error: %s\n", sqlite3_errmsg(p->db));
    sqlite3_finalize(pStmt);
    return 1;
  }
  sqlite3_bind_text(pStmt, 1, zDb, -1, SQLITE_STATIC);
  if( sqlite3_step(pStmt)==SQLITE_ROW
   && sqlite3_column_bytes(pStmt,0)>100
  ){
    const u8 *pb = sqlite3_column_blob(pStmt,0);
    shell_check_oom(pb);
    memcpy(aHdr, pb, 100);
    sqlite3_finalize(pStmt);
  }else{
    cli_puts("unable to read database header\n", stderr);
    sqlite3_finalize(pStmt);
    return 1;
  }
  i = get2byteInt(aHdr+16);
  if( i==1 ) i = 65536;
  cli_printf(p->out, "%-20s %d\n", "database page size:", i);
  cli_printf(p->out, "%-20s %d\n", "write format:", aHdr[18]);
  cli_printf(p->out, "%-20s %d\n", "read format:", aHdr[19]);
  cli_printf(p->out, "%-20s %d\n", "reserved bytes:", aHdr[20]);
  for(i=0; i<ArraySize(aField); i++){
    int ofst = aField[i].ofst;
    unsigned int val = get4byteInt(aHdr + ofst);
    cli_printf(p->out, "%-20s %u", aField[i].zName, val);
    switch( ofst ){
      case 56: {
        if( val==1 ) cli_puts(" (utf8)", p->out);
        if( val==2 ) cli_puts(" (utf16le)", p->out);
        if( val==3 ) cli_puts(" (utf16be)", p->out);
      }
    }
    cli_puts("\n", p->out);
  }
  if( zDb==0 ){
    zSchemaTab = sqlite3_mprintf("main.sqlite_schema");
  }else if( cli_strcmp(zDb,"temp")==0 ){
    zSchemaTab = sqlite3_mprintf("%s", "sqlite_temp_schema");
  }else{
    zSchemaTab = sqlite3_mprintf("\"%w\".sqlite_schema", zDb);
  }
  for(i=0; i<ArraySize(aQuery); i++){
    int val = db_int(p->db, aQuery[i].zSql, zSchemaTab);
    cli_printf(p->out, "%-20s %d\n", aQuery[i].zName, val);
  }
  sqlite3_free(zSchemaTab);
  sqlite3_file_control(p->db, zDb, SQLITE_FCNTL_DATA_VERSION, &iDataVersion);
  cli_printf(p->out, "%-20s %u\n", "data version", iDataVersion);
  return 0;
}
#endif /* SQLITE_SHELL_HAVE_RECOVER */

/*
** Implementation of the ".dbtotxt" command.
**
** Return 1 on error, 2 to exit, and 0 otherwise.
*/
static int shell_dbtotxt_command(ShellState *p, int nArg, char **azArg){
  sqlite3_stmt *pStmt = 0;
  sqlite3_int64 nPage = 0;
  int pgSz = 0;
  const char *zTail;
  char *zName = 0;
  int rc, i, j;
  unsigned char bShow[256];   /* Characters ok to display */

  UNUSED_PARAMETER(nArg);
  UNUSED_PARAMETER(azArg);
  memset(bShow, '.', sizeof(bShow));
  for(i=' '; i<='~'; i++){
    if( i!='{' && i!='}' && i!='"' && i!='\\' ) bShow[i] = (unsigned char)i;
  }
  rc = sqlite3_prepare_v2(p->db, "PRAGMA page_size", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;
  rc = 0;
  if( sqlite3_step(pStmt)!=SQLITE_ROW ) goto dbtotxt_error;
  pgSz = sqlite3_column_int(pStmt, 0);
  sqlite3_finalize(pStmt);
  pStmt = 0;
  if( pgSz<512 || pgSz>65536 || (pgSz&(pgSz-1))!=0 ) goto dbtotxt_error;
  rc = sqlite3_prepare_v2(p->db, "PRAGMA page_count", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;
  rc = 0;
  if( sqlite3_step(pStmt)!=SQLITE_ROW ) goto dbtotxt_error;
  nPage = sqlite3_column_int64(pStmt, 0);
  sqlite3_finalize(pStmt);
  pStmt = 0;
  if( nPage<1 ) goto dbtotxt_error;
  rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;
  if( sqlite3_step(pStmt)!=SQLITE_ROW ){
    zTail = "unk.db";
  }else{
    const char *zFilename = (const char*)sqlite3_column_text(pStmt, 2);
    if( zFilename==0 || zFilename[0]==0 ) zFilename = "unk.db";
    zTail = strrchr(zFilename, '/');
#if defined(_WIN32)
    if( zTail==0 ) zTail = strrchr(zFilename, '\\');
#endif
    if( zTail==0 ){
      zTail = zFilename;
    }else if( zTail[1]!=0 ){
      zTail++;
    }
  }
  zName = strdup(zTail);
  shell_check_oom(zName);
  cli_printf(p->out, "| size %lld pagesize %d filename %s\n",
                  nPage*pgSz, pgSz, zName);
  sqlite3_finalize(pStmt);
  pStmt = 0;
  rc = sqlite3_prepare_v2(p->db,
           "SELECT pgno, data FROM sqlite_dbpage ORDER BY pgno", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    sqlite3_int64 pgno = sqlite3_column_int64(pStmt, 0);
    const u8 *aData = sqlite3_column_blob(pStmt, 1);
    int seenPageLabel = 0;
    for(i=0; i<pgSz; i+=16){
      const u8 *aLine = aData+i;
      for(j=0; j<16 && aLine[j]==0; j++){}
      if( j==16 ) continue;
      if( !seenPageLabel ){
        cli_printf(p->out, "| page %lld offset %lld\n",pgno,(pgno-1)*pgSz);
        seenPageLabel = 1;
      }
      cli_printf(p->out, "|  %5d:", i);
      for(j=0; j<16; j++) cli_printf(p->out, " %02x", aLine[j]);
      cli_printf(p->out, "   ");
      for(j=0; j<16; j++){
        unsigned char c = (unsigned char)aLine[j];
        cli_printf(p->out, "%c", bShow[c]);
      }
      cli_printf(p->out, "\n");
    }
  }
  sqlite3_finalize(pStmt);
  cli_printf(p->out, "| end %s\n", zName);
  free(zName);
  return 0;

dbtotxt_error:
  if( rc ){
    cli_printf(stderr, "ERROR: %s\n", sqlite3_errmsg(p->db));
  }
  sqlite3_finalize(pStmt);
  free(zName);
  return 1;
}

/*
** Print the given string as an error message.
*/
static void shellEmitError(const char *zErr){
  cli_printf(stderr,"Error: %s\n", zErr);
}
/*
** Print the current sqlite3_errmsg() value to stderr and return 1.
*/
static int shellDatabaseError(sqlite3 *db){
  shellEmitError(sqlite3_errmsg(db));
  return 1;
}

/*
** Compare the pattern in zGlob[] against the text in z[].  Return TRUE
** if they match and FALSE (0) if they do not match.
**
** Globbing rules:
**
**      '*'       Matches any sequence of zero or more characters.
**
**      '?'       Matches exactly one character.
**
**     [...]      Matches one character from the enclosed list of
**                characters.
**
**     [^...]     Matches one character not in the enclosed list.
**
**      '#'       Matches any sequence of one or more digits with an
**                optional + or - sign in front
**
**      ' '       Any span of whitespace matches any other span of
**                whitespace.
**
** Extra whitespace at the end of z[] is ignored.
*/
static int testcase_glob(const char *zGlob, const char *z){
  int c, c2;
  int invert;
  int seen;

  while( (c = (*(zGlob++)))!=0 ){
    if( IsSpace(c) ){
      if( !IsSpace(*z) ) return 0;
      while( IsSpace(*zGlob) ) zGlob++;
      while( IsSpace(*z) ) z++;
    }else if( c=='*' ){
      while( (c=(*(zGlob++))) == '*' || c=='?' ){
        if( c=='?' && (*(z++))==0 ) return 0;
      }
      if( c==0 ){
        return 1;
      }else if( c=='[' ){
        while( *z && testcase_glob(zGlob-1,z)==0 ){
          z++;
        }
        return (*z)!=0;
      }
      while( (c2 = (*(z++)))!=0 ){
        while( c2!=c ){
          c2 = *(z++);
          if( c2==0 ) return 0;
        }
        if( testcase_glob(zGlob,z) ) return 1;
      }
      return 0;
    }else if( c=='?' ){
      if( (*(z++))==0 ) return 0;
    }else if( c=='[' ){
      int prior_c = 0;
      seen = 0;
      invert = 0;
      c = *(z++);
      if( c==0 ) return 0;
      c2 = *(zGlob++);
      if( c2=='^' ){
        invert = 1;
        c2 = *(zGlob++);
      }
      if( c2==']' ){
        if( c==']' ) seen = 1;
        c2 = *(zGlob++);
      }
      while( c2 && c2!=']' ){
        if( c2=='-' && zGlob[0]!=']' && zGlob[0]!=0 && prior_c>0 ){
          c2 = *(zGlob++);
          if( c>=prior_c && c<=c2 ) seen = 1;
          prior_c = 0;
        }else{
          if( c==c2 ){
            seen = 1;
          }
          prior_c = c2;
        }
        c2 = *(zGlob++);
      }
      if( c2==0 || (seen ^ invert)==0 ) return 0;
    }else if( c=='#' ){
      if( (z[0]=='-' || z[0]=='+') && IsDigit(z[1]) ) z++;
      if( !IsDigit(z[0]) ) return 0;
      z++;
      while( IsDigit(z[0]) ){ z++; }
    }else{
      if( c!=(*(z++)) ) return 0;
    }
  }
  while( IsSpace(*z) ){ z++; }
  return *z==0;
}


/*
** Compare the string as a command-line option with either one or two
** initial "-" characters.
*/
static int optionMatch(const char *zStr, const char *zOpt){
  if( zStr[0]!='-' ) return 0;
  zStr++;
  if( zStr[0]=='-' ) zStr++;
  return cli_strcmp(zStr, zOpt)==0;
}

/*
** The input zFN is guaranteed to start with "file:" and is thus a URI
** filename.  Extract the actual filename and return a pointer to that
** filename in spaced obtained from sqlite3_malloc().
**
** The caller is responsible for freeing space using sqlite3_free() when
** it has finished with the filename.
*/
static char *shellFilenameFromUri(const char *zFN){
  char *zOut;
  int i, j, d1, d2;

  assert( cli_strncmp(zFN,"file:",5)==0 );
  zOut = sqlite3_mprintf("%s", zFN+5);
  shell_check_oom(zOut);
  for(i=j=0; zOut[i]!=0 && zOut[i]!='?'; i++){
    if( zOut[i]!='%' ){
      zOut[j++] = zOut[i];
      continue;
    }
    d1 = hexDigitValue(zOut[i+1]);
    if( d1<0 ){
      zOut[j] = 0;
      break;
    }
    d2 = hexDigitValue(zOut[i+2]);
    if( d2<0 ){
      zOut[j] = 0;
      break;
    }
    zOut[j++] = d1*16 + d2;
    i += 2;
  }
  zOut[j] = 0;
  return zOut;
}

/*
** Delete a file.
*/
int shellDeleteFile(const char *zFilename){
  int rc;
#ifdef _WIN32
  wchar_t *z = sqlite3_win32_utf8_to_unicode(zFilename);
  rc = _wunlink(z);
  sqlite3_free(z);
#else
  rc = unlink(zFilename);
#endif
  return rc;
}

/*
** Try to delete the temporary file (if there is one) and free the
** memory used to hold the name of the temp file.
*/
static void clearTempFile(ShellState *p){
  if( p->zTempFile==0 ) return;
  if( p->doXdgOpen ) return;
  if( shellDeleteFile(p->zTempFile) ) return;
  sqlite3_free(p->zTempFile);
  p->zTempFile = 0;
}

/* Forward reference */
static char *find_home_dir(int clearFlag);

/*
** Create a new temp file name with the given suffix.
**
** Because the classic temp folders like /tmp are no longer
** accessible to web browsers, for security reasons, create the
** temp file in the user's home directory.
*/
static void newTempFile(ShellState *p, const char *zSuffix){
  char *zHome;          /* Home directory */
  int i;                /* Loop counter */
  sqlite3_uint64 r = 0; /* Integer with 64 bits of randomness */
  char zRand[32];       /* Text string with 160 bits of randomness */
#ifdef _WIN32
  const char cDirSep = '\\';
#else
  const char cDirSep = '/';
#endif

  for(i=0; i<31; i++){
    if( (i%12)==0 ) sqlite3_randomness(sizeof(r),&r);
    zRand[i] = "0123456789abcdefghijklmnopqrstuvwxyz"[r%36];
    r /= 36;
  }
  zRand[i] = 0;
  clearTempFile(p);
  sqlite3_free(p->zTempFile);
  p->zTempFile = 0;
  zHome = find_home_dir(0);
  p->zTempFile = sqlite3_mprintf("%s%ctemp-%s.%s",
                                 zHome,cDirSep,zRand,zSuffix);
  shell_check_oom(p->zTempFile);
}

/*
** The implementation of SQL scalar function fkey_collate_clause(), used
** by the ".lint fkey-indexes" command. This scalar function is always
** called with four arguments - the parent table name, the parent column name,
** the child table name and the child column name.
**
**   fkey_collate_clause('parent-tab', 'parent-col', 'child-tab', 'child-col')
**
** If either of the named tables or columns do not exist, this function
** returns an empty string. An empty string is also returned if both tables
** and columns exist but have the same default collation sequence. Or,
** if both exist but the default collation sequences are different, this
** function returns the string " COLLATE <parent-collation>", where
** <parent-collation> is the default collation sequence of the parent column.
*/
static void shellFkeyCollateClause(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  sqlite3 *db = sqlite3_context_db_handle(pCtx);
  const char *zParent;
  const char *zParentCol;
  const char *zParentSeq;
  const char *zChild;
  const char *zChildCol;
  const char *zChildSeq = 0;  /* Initialize to avoid false-positive warning */
  int rc;

  assert( nVal==4 );
  zParent = (const char*)sqlite3_value_text(apVal[0]);
  zParentCol = (const char*)sqlite3_value_text(apVal[1]);
  zChild = (const char*)sqlite3_value_text(apVal[2]);
  zChildCol = (const char*)sqlite3_value_text(apVal[3]);

  sqlite3_result_text(pCtx, "", -1, SQLITE_STATIC);
  rc = sqlite3_table_column_metadata(
      db, "main", zParent, zParentCol, 0, &zParentSeq, 0, 0, 0
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3_table_column_metadata(
        db, "main", zChild, zChildCol, 0, &zChildSeq, 0, 0, 0
    );
  }

  if( rc==SQLITE_OK && sqlite3_stricmp(zParentSeq, zChildSeq) ){
    char *z = sqlite3_mprintf(" COLLATE %s", zParentSeq);
    sqlite3_result_text(pCtx, z, -1, SQLITE_TRANSIENT);
    sqlite3_free(z);
  }
}


/*
** The implementation of dot-command ".lint fkey-indexes".
*/
static int lintFkeyIndexes(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  sqlite3 *db = pState->db;       /* Database handle to query "main" db of */
  int bVerbose = 0;               /* If -verbose is present */
  int bGroupByParent = 0;         /* If -groupbyparent is present */
  int i;                          /* To iterate through azArg[] */
  const char *zIndent = "";       /* How much to indent CREATE INDEX by */
  int rc;                         /* Return code */
  sqlite3_stmt *pSql = 0;         /* Compiled version of SQL statement below */
  FILE *out = pState->out;        /* Send output here */

  /*
  ** This SELECT statement returns one row for each foreign key constraint
  ** in the schema of the main database. The column values are:
  **
  ** 0. The text of an SQL statement similar to:
  **
  **      "EXPLAIN QUERY PLAN SELECT 1 FROM child_table WHERE child_key=?"
  **
  **    This SELECT is similar to the one that the foreign keys implementation
  **    needs to run internally on child tables. If there is an index that can
  **    be used to optimize this query, then it can also be used by the FK
  **    implementation to optimize DELETE or UPDATE statements on the parent
  **    table.
  **
  ** 1. A GLOB pattern suitable for sqlite3_strglob(). If the plan output by
  **    the EXPLAIN QUERY PLAN command matches this pattern, then the schema
  **    contains an index that can be used to optimize the query.
  **
  ** 2. Human readable text that describes the child table and columns. e.g.
  **
  **       "child_table(child_key1, child_key2)"
  **
  ** 3. Human readable text that describes the parent table and columns. e.g.
  **
  **       "parent_table(parent_key1, parent_key2)"
  **
  ** 4. A full CREATE INDEX statement for an index that could be used to
  **    optimize DELETE or UPDATE statements on the parent table. e.g.
  **
  **       "CREATE INDEX child_table_child_key ON child_table(child_key)"
  **
  ** 5. The name of the parent table.
  **
  ** These six values are used by the C logic below to generate the report.
  */
  const char *zSql =
  "SELECT "
    "     'EXPLAIN QUERY PLAN SELECT 1 FROM ' || quote(s.name) || ' WHERE '"
    "  || group_concat(quote(s.name) || '.' || quote(f.[from]) || '=?' "
    "  || fkey_collate_clause("
    "       f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]),' AND ')"
    ", "
    "     'SEARCH ' || s.name || ' USING COVERING INDEX*('"
    "  || group_concat('*=?', ' AND ') || ')'"
    ", "
    "     s.name  || '(' || group_concat(f.[from],  ', ') || ')'"
    ", "
    "     f.[table] || '(' || group_concat(COALESCE(f.[to], p.[name])) || ')'"
    ", "
    "     'CREATE INDEX ' || quote(s.name ||'_'|| group_concat(f.[from], '_'))"
    "  || ' ON ' || quote(s.name) || '('"
    "  || group_concat(quote(f.[from]) ||"
    "        fkey_collate_clause("
    "          f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]), ', ')"
    "  || ');'"
    ", "
    "     f.[table] "
    "FROM sqlite_schema AS s, pragma_foreign_key_list(s.name) AS f "
    "LEFT JOIN pragma_table_info AS p ON (pk-1=seq AND p.arg=f.[table]) "
    "GROUP BY s.name, f.id "
    "ORDER BY (CASE WHEN ? THEN f.[table] ELSE s.name END)"
  ;
  const char *zGlobIPK = "SEARCH * USING INTEGER PRIMARY KEY (rowid=?)";

  for(i=2; i<nArg; i++){
    int n = strlen30(azArg[i]);
    if( n>1 && sqlite3_strnicmp("-verbose", azArg[i], n)==0 ){
      bVerbose = 1;
    }
    else if( n>1 && sqlite3_strnicmp("-groupbyparent", azArg[i], n)==0 ){
      bGroupByParent = 1;
      zIndent = "    ";
    }
    else{
      cli_printf(stderr,
           "Usage: %s %s ?-verbose? ?-groupbyparent?\n", azArg[0], azArg[1]);
      return SQLITE_ERROR;
    }
  }

  /* Register the fkey_collate_clause() SQL function */
  rc = sqlite3_create_function(db, "fkey_collate_clause", 4, SQLITE_UTF8,
      0, shellFkeyCollateClause, 0, 0
  );


  if( rc==SQLITE_OK ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pSql, 0);
  }
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pSql, 1, bGroupByParent);
  }

  if( rc==SQLITE_OK ){
    int rc2;
    char *zPrev = 0;
    while( SQLITE_ROW==sqlite3_step(pSql) ){
      int res = -1;
      sqlite3_stmt *pExplain = 0;
      const char *zEQP = (const char*)sqlite3_column_text(pSql, 0);
      const char *zGlob = (const char*)sqlite3_column_text(pSql, 1);
      const char *zFrom = (const char*)sqlite3_column_text(pSql, 2);
      const char *zTarget = (const char*)sqlite3_column_text(pSql, 3);
      const char *zCI = (const char*)sqlite3_column_text(pSql, 4);
      const char *zParent = (const char*)sqlite3_column_text(pSql, 5);

      if( zEQP==0 ) continue;
      if( zGlob==0 ) continue;
      rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
      if( rc!=SQLITE_OK ) break;
      if( SQLITE_ROW==sqlite3_step(pExplain) ){
        const char *zPlan = (const char*)sqlite3_column_text(pExplain, 3);
        res = zPlan!=0 && (  0==sqlite3_strglob(zGlob, zPlan)
                          || 0==sqlite3_strglob(zGlobIPK, zPlan));
      }
      rc = sqlite3_finalize(pExplain);
      if( rc!=SQLITE_OK ) break;

      if( res<0 ){
        cli_puts("Error: internal error", stderr);
        break;
      }else{
        if( bGroupByParent
        && (bVerbose || res==0)
        && (zPrev==0 || sqlite3_stricmp(zParent, zPrev))
        ){
          cli_printf(out, "-- Parent table %s\n", zParent);
          sqlite3_free(zPrev);
          zPrev = sqlite3_mprintf("%s", zParent);
        }

        if( res==0 ){
          cli_printf(out, "%s%s --> %s\n", zIndent, zCI, zTarget);
        }else if( bVerbose ){
          cli_printf(out,
                "%s/* no extra indexes required for %s -> %s */\n",
                zIndent, zFrom, zTarget
          );
        }
      }
    }
    sqlite3_free(zPrev);

    if( rc!=SQLITE_OK ){
      cli_printf(stderr,"%s\n", sqlite3_errmsg(db));
    }

    rc2 = sqlite3_finalize(pSql);
    if( rc==SQLITE_OK && rc2!=SQLITE_OK ){
      rc = rc2;
      cli_printf(stderr,"%s\n", sqlite3_errmsg(db));
    }
  }else{
    cli_printf(stderr,"%s\n", sqlite3_errmsg(db));
  }

  return rc;
}

/*
** Implementation of ".lint" dot command.
*/
static int lintDotCommand(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  int n;
  n = (nArg>=2 ? strlen30(azArg[1]) : 0);
  if( n<1 || sqlite3_strnicmp(azArg[1], "fkey-indexes", n) ) goto usage;
  return lintFkeyIndexes(pState, azArg, nArg);

 usage:
  cli_printf(stderr,"Usage %s sub-command ?switches...?\n", azArg[0]);
  cli_printf(stderr, "Where sub-commands are:\n");
  cli_printf(stderr, "    fkey-indexes\n");
  return SQLITE_ERROR;
}

static void shellPrepare(
  sqlite3 *db,
  int *pRc,
  const char *zSql,
  sqlite3_stmt **ppStmt
){
  *ppStmt = 0;
  if( *pRc==SQLITE_OK ){
    int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
    if( rc!=SQLITE_OK ){
      cli_printf(stderr,
         "sql error: %s (%d)\n", sqlite3_errmsg(db), sqlite3_errcode(db));
      *pRc = rc;
    }
  }
}

/*
** Create a prepared statement using printf-style arguments for the SQL.
*/
static void shellPreparePrintf(
  sqlite3 *db,
  int *pRc,
  sqlite3_stmt **ppStmt,
  const char *zFmt,
  ...
){
  *ppStmt = 0;
  if( *pRc==SQLITE_OK ){
    va_list ap;
    char *z;
    va_start(ap, zFmt);
    z = sqlite3_vmprintf(zFmt, ap);
    va_end(ap);
    if( z==0 ){
      *pRc = SQLITE_NOMEM;
    }else{
      shellPrepare(db, pRc, z, ppStmt);
      sqlite3_free(z);
    }
  }
}

/* 
** Finalize the prepared statement created using shellPreparePrintf().
*/
static void shellFinalize(
  int *pRc,
  sqlite3_stmt *pStmt
){
  if( pStmt ){
    sqlite3 *db = sqlite3_db_handle(pStmt);
    int rc = sqlite3_finalize(pStmt);
    if( *pRc==SQLITE_OK ){
      if( rc!=SQLITE_OK ){
        cli_printf(stderr,"SQL error: %s\n", sqlite3_errmsg(db));
      }
      *pRc = rc;
    }
  }
}

#if !defined SQLITE_OMIT_VIRTUALTABLE
/* Reset the prepared statement created using shellPreparePrintf().
**
** This routine is could be marked "static".  But it is not always used,
** depending on compile-time options.  By omitting the "static", we avoid
** nuisance compiler warnings about "defined but not used".
*/
void shellReset(
  int *pRc,
  sqlite3_stmt *pStmt
){
  int rc = sqlite3_reset(pStmt);
  if( *pRc==SQLITE_OK ){
    if( rc!=SQLITE_OK ){
      sqlite3 *db = sqlite3_db_handle(pStmt);
      cli_printf(stderr,"SQL error: %s\n", sqlite3_errmsg(db));
    }
    *pRc = rc;
  }
}
#endif /* !defined SQLITE_OMIT_VIRTUALTABLE */

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
/******************************************************************************
** The ".archive" or ".ar" command.
*/
/*
** Structure representing a single ".ar" command.
*/
typedef struct ArCommand ArCommand;
struct ArCommand {
  u8 eCmd;                        /* An AR_CMD_* value */
  u8 bVerbose;                    /* True if --verbose */
  u8 bZip;                        /* True if the archive is a ZIP */
  u8 bDryRun;                     /* True if --dry-run */
  u8 bAppend;                     /* True if --append */
  u8 bGlob;                       /* True if --glob */
  u8 fromCmdLine;                 /* Run from -A instead of .archive */
  int nArg;                       /* Number of command arguments */
  char *zSrcTable;                /* "sqlar", "zipfile($file)" or "zip" */
  const char *zFile;              /* --file argument, or NULL */
  const char *zDir;               /* --directory argument, or NULL */
  char **azArg;                   /* Array of command arguments */
  ShellState *p;                  /* Shell state */
  FILE *out;                      /* Output to this stream */
  sqlite3 *db;                    /* Database containing the archive */
};

/*
** Print a usage message for the .ar command to stderr and return SQLITE_ERROR.
*/
static int arUsage(FILE *f){
  showHelp(f,"archive");
  return SQLITE_ERROR;
}

/*
** Print an error message for the .ar command to stderr and return
** SQLITE_ERROR.
*/
static int arErrorMsg(ArCommand *pAr, const char *zFmt, ...){
  va_list ap;
  char *z;
  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
  shellEmitError(z);
  if( pAr->fromCmdLine ){
    cli_puts("Use \"-A\" for more help\n", stderr);
  }else{
    cli_puts("Use \".archive --help\" for more help\n", stderr);
  }
  sqlite3_free(z);
  return SQLITE_ERROR;
}

/*
** Values for ArCommand.eCmd.
*/
#define AR_CMD_CREATE       1
#define AR_CMD_UPDATE       2
#define AR_CMD_INSERT       3
#define AR_CMD_EXTRACT      4
#define AR_CMD_LIST         5
#define AR_CMD_HELP         6
#define AR_CMD_REMOVE       7

/*
** Other (non-command) switches.
*/
#define AR_SWITCH_VERBOSE     8
#define AR_SWITCH_FILE        9
#define AR_SWITCH_DIRECTORY  10
#define AR_SWITCH_APPEND     11
#define AR_SWITCH_DRYRUN     12
#define AR_SWITCH_GLOB       13

static int arProcessSwitch(ArCommand *pAr, int eSwitch, const char *zArg){
  switch( eSwitch ){
    case AR_CMD_CREATE:
    case AR_CMD_EXTRACT:
    case AR_CMD_LIST:
    case AR_CMD_REMOVE:
    case AR_CMD_UPDATE:
    case AR_CMD_INSERT:
    case AR_CMD_HELP:
      if( pAr->eCmd ){
        return arErrorMsg(pAr, "multiple command options");
      }
      pAr->eCmd = eSwitch;
      break;

    case AR_SWITCH_DRYRUN:
      pAr->bDryRun = 1;
      break;
    case AR_SWITCH_GLOB:
      pAr->bGlob = 1;
      break;
    case AR_SWITCH_VERBOSE:
      pAr->bVerbose = 1;
      break;
    case AR_SWITCH_APPEND:
      pAr->bAppend = 1;
      deliberate_fall_through; /* FALLTHRU */
    case AR_SWITCH_FILE:
      pAr->zFile = zArg;
      break;
    case AR_SWITCH_DIRECTORY:
      pAr->zDir = zArg;
      break;
  }

  return SQLITE_OK;
}

/*
** Parse the command line for an ".ar" command. The results are written into
** structure (*pAr). SQLITE_OK is returned if the command line is parsed
** successfully, otherwise an error message is written to stderr and
** SQLITE_ERROR returned.
*/
static int arParseCommand(
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg,                       /* Number of entries in azArg[] */
  ArCommand *pAr                  /* Populate this object */
){
  struct ArSwitch {
    const char *zLong;
    char cShort;
    u8 eSwitch;
    u8 bArg;
  } aSwitch[] = {
    { "create",    'c', AR_CMD_CREATE,       0 },
    { "extract",   'x', AR_CMD_EXTRACT,      0 },
    { "insert",    'i', AR_CMD_INSERT,       0 },
    { "list",      't', AR_CMD_LIST,         0 },
    { "remove",    'r', AR_CMD_REMOVE,       0 },
    { "update",    'u', AR_CMD_UPDATE,       0 },
    { "help",      'h', AR_CMD_HELP,         0 },
    { "verbose",   'v', AR_SWITCH_VERBOSE,   0 },
    { "file",      'f', AR_SWITCH_FILE,      1 },
    { "append",    'a', AR_SWITCH_APPEND,    1 },
    { "directory", 'C', AR_SWITCH_DIRECTORY, 1 },
    { "dryrun",    'n', AR_SWITCH_DRYRUN,    0 },
    { "glob",      'g', AR_SWITCH_GLOB,      0 },
  };
  int nSwitch = sizeof(aSwitch) / sizeof(struct ArSwitch);
  struct ArSwitch *pEnd = &aSwitch[nSwitch];

  if( nArg<=1 ){
    cli_printf(stderr, "Wrong number of arguments.  Usage:\n");
    return arUsage(stderr);
  }else{
    char *z = azArg[1];
    if( z[0]!='-' ){
      /* Traditional style [tar] invocation */
      int i;
      int iArg = 2;
      for(i=0; z[i]; i++){
        const char *zArg = 0;
        struct ArSwitch *pOpt;
        for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
          if( z[i]==pOpt->cShort ) break;
        }
        if( pOpt==pEnd ){
          return arErrorMsg(pAr, "unrecognized option: %c", z[i]);
        }
        if( pOpt->bArg ){
          if( iArg>=nArg ){
            return arErrorMsg(pAr, "option requires an argument: %c",z[i]);
          }
          zArg = azArg[iArg++];
        }
        if( arProcessSwitch(pAr, pOpt->eSwitch, zArg) ) return SQLITE_ERROR;
      }
      pAr->nArg = nArg-iArg;
      if( pAr->nArg>0 ){
        pAr->azArg = &azArg[iArg];
      }
    }else{
      /* Non-traditional invocation */
      int iArg;
      for(iArg=1; iArg<nArg; iArg++){
        int n;
        z = azArg[iArg];
        if( z[0]!='-' ){
          /* All remaining command line words are command arguments. */
          pAr->azArg = &azArg[iArg];
          pAr->nArg = nArg-iArg;
          break;
        }
        n = strlen30(z);

        if( z[1]!='-' ){
          int i;
          /* One or more short options */
          for(i=1; i<n; i++){
            const char *zArg = 0;
            struct ArSwitch *pOpt;
            for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
              if( z[i]==pOpt->cShort ) break;
            }
            if( pOpt==pEnd ){
              return arErrorMsg(pAr, "unrecognized option: %c", z[i]);
            }
            if( pOpt->bArg ){
              if( i<(n-1) ){
                zArg = &z[i+1];
                i = n;
              }else{
                if( iArg>=(nArg-1) ){
                  return arErrorMsg(pAr, "option requires an argument: %c",
                                    z[i]);
                }
                zArg = azArg[++iArg];
              }
            }
            if( arProcessSwitch(pAr, pOpt->eSwitch, zArg) ) return SQLITE_ERROR;
          }
        }else if( z[2]=='\0' ){
          /* A -- option, indicating that all remaining command line words
          ** are command arguments.  */
          pAr->azArg = &azArg[iArg+1];
          pAr->nArg = nArg-iArg-1;
          break;
        }else{
          /* A long option */
          const char *zArg = 0;             /* Argument for option, if any */
          struct ArSwitch *pMatch = 0;      /* Matching option */
          struct ArSwitch *pOpt;            /* Iterator */
          for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
            const char *zLong = pOpt->zLong;
            if( (n-2)<=strlen30(zLong) && 0==memcmp(&z[2], zLong, n-2) ){
              if( pMatch ){
                return arErrorMsg(pAr, "ambiguous option: %s",z);
              }else{
                pMatch = pOpt;
              }
            }
          }

          if( pMatch==0 ){
            return arErrorMsg(pAr, "unrecognized option: %s", z);
          }
          if( pMatch->bArg ){
            if( iArg>=(nArg-1) ){
              return arErrorMsg(pAr, "option requires an argument: %s", z);
            }
            zArg = azArg[++iArg];
          }
          if( arProcessSwitch(pAr, pMatch->eSwitch, zArg) ) return SQLITE_ERROR;
        }
      }
    }
  }
  if( pAr->eCmd==0 ){
    cli_printf(stderr, "Required argument missing.  Usage:\n");
    return arUsage(stderr);
  }
  return SQLITE_OK;
}

/*
** This function assumes that all arguments within the ArCommand.azArg[]
** array refer to archive members, as for the --extract, --list or --remove
** commands. It checks that each of them are "present". If any specified
** file is not present in the archive, an error is printed to stderr and an
** error code returned. Otherwise, if all specified arguments are present
** in the archive, SQLITE_OK is returned. Here, "present" means either an
** exact equality when pAr->bGlob is false or a "name GLOB pattern" match
** when pAr->bGlob is true.
**
** This function strips any trailing '/' characters from each argument.
** This is consistent with the way the [tar] command seems to work on
** Linux.
*/
static int arCheckEntries(ArCommand *pAr){
  int rc = SQLITE_OK;
  if( pAr->nArg ){
    int i, j;
    sqlite3_stmt *pTest = 0;
    const char *zSel = (pAr->bGlob)
      ? "SELECT name FROM %s WHERE glob($name,name)"
      : "SELECT name FROM %s WHERE name=$name";

    shellPreparePrintf(pAr->db, &rc, &pTest, zSel, pAr->zSrcTable);
    j = sqlite3_bind_parameter_index(pTest, "$name");
    for(i=0; i<pAr->nArg && rc==SQLITE_OK; i++){
      char *z = pAr->azArg[i];
      int n = strlen30(z);
      int bOk = 0;
      while( n>0 && z[n-1]=='/' ) n--;
      z[n] = '\0';
      sqlite3_bind_text(pTest, j, z, -1, SQLITE_STATIC);
      if( SQLITE_ROW==sqlite3_step(pTest) ){
        bOk = 1;
      }
      shellReset(&rc, pTest);
      if( rc==SQLITE_OK && bOk==0 ){
        cli_printf(stderr,"not found in archive: %s\n", z);
        rc = SQLITE_ERROR;
      }
    }
    shellFinalize(&rc, pTest);
  }
  return rc;
}

/*
** Format a WHERE clause that can be used against the "sqlar" table to
** identify all archive members that match the command arguments held
** in (*pAr). Leave this WHERE clause in (*pzWhere) before returning.
** The caller is responsible for eventually calling sqlite3_free() on
** any non-NULL (*pzWhere) value. Here, "match" means strict equality
** when pAr->bGlob is false and GLOB match when pAr->bGlob is true.
*/
static void arWhereClause(
  int *pRc,
  ArCommand *pAr,
  char **pzWhere                  /* OUT: New WHERE clause */
){
  char *zWhere = 0;
  if( *pRc==SQLITE_OK ){
    if( pAr->nArg==0 ){
      zWhere = sqlite3_mprintf("1");
    }else{
      char *z1 = sqlite3_mprintf(pAr->bGlob ? "" : "name IN(");
      char *z2 = sqlite3_mprintf("");
      const char *zSep1 = "";
      const char *zSep2 = "";

      int i;
      for(i=0; i<pAr->nArg && z1 && z2; i++){
        const char *z = pAr->azArg[i];
        int n = strlen30(z);

        if( pAr->bGlob ){
          z1 = sqlite3_mprintf("%z%sname GLOB '%q'", z1, zSep2, z);
          z2 = sqlite3_mprintf(
              "%z%ssubstr(name,1,%d) GLOB '%q/'", z2, zSep2, n+1,z
          );
        }else{
          z1 = sqlite3_mprintf("%z%s'%q'", z1, zSep1, z);
          z2 = sqlite3_mprintf("%z%ssubstr(name,1,%d) = '%q/'",z2,zSep2,n+1,z);
        }
        zSep1 = ", ";
        zSep2 = " OR ";
      }
      if( z1==0 || z2==0 ){
        *pRc = SQLITE_NOMEM;
      }else{
        zWhere = sqlite3_mprintf("(%s%s OR (name GLOB '*/*' AND (%s))) ",
            z1, pAr->bGlob==0 ? ")" : "", z2
        );
      }
      sqlite3_free(z1);
      sqlite3_free(z2);
    }
  }
  *pzWhere = zWhere;
}

/*
** Implementation of .ar "lisT" command.
*/
static int arListCommand(ArCommand *pAr){
  const char *zSql = "SELECT %s FROM %s WHERE %s";
  const char *azCols[] = {
    "name",
    "lsmode(mode), sz, datetime(mtime, 'unixepoch'), name"
  };

  char *zWhere = 0;
  sqlite3_stmt *pSql = 0;
  int rc;

  rc = arCheckEntries(pAr);
  arWhereClause(&rc, pAr, &zWhere);

  shellPreparePrintf(pAr->db, &rc, &pSql, zSql, azCols[pAr->bVerbose],
                     pAr->zSrcTable, zWhere);
  if( pAr->bDryRun ){
    cli_printf(pAr->out, "%s\n", sqlite3_sql(pSql));
  }else{
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
      if( pAr->bVerbose ){
        cli_printf(pAr->out, "%s % 10d  %s  %s\n",
              sqlite3_column_text(pSql, 0), sqlite3_column_int(pSql, 1),
              sqlite3_column_text(pSql, 2),sqlite3_column_text(pSql, 3));
      }else{
        cli_printf(pAr->out, "%s\n", sqlite3_column_text(pSql, 0));
      }
    }
  }
  shellFinalize(&rc, pSql);
  sqlite3_free(zWhere);
  return rc;
}

/*
** Implementation of .ar "Remove" command.
*/
static int arRemoveCommand(ArCommand *pAr){
  int rc = 0;
  char *zSql = 0;
  char *zWhere = 0;

  if( pAr->nArg ){
    /* Verify that args actually exist within the archive before proceeding.
    ** And formulate a WHERE clause to match them.  */
    rc = arCheckEntries(pAr);
    arWhereClause(&rc, pAr, &zWhere);
  }
  if( rc==SQLITE_OK ){
    zSql = sqlite3_mprintf("DELETE FROM %s WHERE %s;",
                           pAr->zSrcTable, zWhere);
    if( pAr->bDryRun ){
      cli_printf(pAr->out, "%s\n", zSql);
    }else{
      char *zErr = 0;
      rc = sqlite3_exec(pAr->db, "SAVEPOINT ar;", 0, 0, 0);
      if( rc==SQLITE_OK ){
        rc = sqlite3_exec(pAr->db, zSql, 0, 0, &zErr);
        if( rc!=SQLITE_OK ){
          sqlite3_exec(pAr->db, "ROLLBACK TO ar; RELEASE ar;", 0, 0, 0);
        }else{
          rc = sqlite3_exec(pAr->db, "RELEASE ar;", 0, 0, 0);
        }
      }
      if( zErr ){
        cli_printf(stdout, "ERROR: %s\n", zErr); /* stdout? */
        sqlite3_free(zErr);
      }
    }
  }
  sqlite3_free(zWhere);
  sqlite3_free(zSql);
  return rc;
}

/*
** Implementation of .ar "eXtract" command.
*/
static int arExtractCommand(ArCommand *pAr){
  const char *zSql1 =
    "WITH dest(dpath,dlen) AS (SELECT realpath($dir),length(realpath($dir)))\n"
    "SELECT ($dir || name),\n"
    "       CASE WHEN $dryrun THEN 0\n"
    "            ELSE writefile($dir||name, %s, mode, mtime) END\n"
    "  FROM dest CROSS JOIN %s\n"
    " WHERE (%s)\n"
    "   AND (data IS NULL OR $pass==0)\n"                /* Dirs both passes */
    "   AND dpath=substr(realpath($dir||name),1,dlen)\n" /* No escapes */
    "   AND name NOT GLOB '*..[/\\]*'\n";                /* No /../ in paths */

  const char *azExtraArg[] = {
    "sqlar_uncompress(data, sz)",
    "data"
  };

  sqlite3_stmt *pSql = 0;
  int rc = SQLITE_OK;
  char *zDir = 0;
  char *zWhere = 0;
  int i, j;

  /* If arguments are specified, check that they actually exist within
  ** the archive before proceeding. And formulate a WHERE clause to
  ** match them.  */
  rc = arCheckEntries(pAr);
  arWhereClause(&rc, pAr, &zWhere);

  if( rc==SQLITE_OK ){
    if( pAr->zDir ){
      zDir = sqlite3_mprintf("%s/", pAr->zDir);
    }else{
      zDir = sqlite3_mprintf("");
    }
    if( zDir==0 ) rc = SQLITE_NOMEM;
  }

  shellPreparePrintf(pAr->db, &rc, &pSql, zSql1,
      azExtraArg[pAr->bZip], pAr->zSrcTable, zWhere
  );

  if( rc==SQLITE_OK ){
    j = sqlite3_bind_parameter_index(pSql, "$dir");
    sqlite3_bind_text(pSql, j, zDir, -1, SQLITE_STATIC);
    j = sqlite3_bind_parameter_index(pSql, "$dryrun");
    sqlite3_bind_int(pSql, j, pAr->bDryRun);

    /* Run the SELECT statement twice
    **   (0) writefile() all files and directories
    **   (1) writefile() for directory again
    ** The second pass is so that the timestamps for extracted directories
    ** will be reset to the value in the archive, since populating them
    ** in the first pass will have changed the timestamp. */
    for(i=0; i<2; i++){
      j = sqlite3_bind_parameter_index(pSql, "$pass");
      sqlite3_bind_int(pSql, j, i);
      if( pAr->bDryRun ){
        cli_printf(pAr->out, "%s\n", sqlite3_sql(pSql));
        if( pAr->bVerbose==0 ) break;
      }
      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
        if( i==0 && pAr->bVerbose ){
          cli_printf(pAr->out, "%s\n", sqlite3_column_text(pSql, 0));
        }
      }
      if( pAr->bDryRun ) break;
      shellReset(&rc, pSql);
    }
    shellFinalize(&rc, pSql);
  }

  sqlite3_free(zDir);
  sqlite3_free(zWhere);
  return rc;
}

/*
** Run the SQL statement in zSql.  Or if doing a --dryrun, merely print it out.
*/
static int arExecSql(ArCommand *pAr, const char *zSql){
  int rc;
  if( pAr->bDryRun ){
    cli_printf(pAr->out, "%s\n", zSql);
    rc = SQLITE_OK;
  }else{
    char *zErr = 0;
    rc = sqlite3_exec(pAr->db, zSql, 0, 0, &zErr);
    if( zErr ){
      cli_printf(stdout, "ERROR: %s\n", zErr);
      sqlite3_free(zErr);
    }
  }
  return rc;
}


/*
** Implementation of .ar "create", "insert", and "update" commands.
**
**     create    ->     Create a new SQL archive
**     insert    ->     Insert or reinsert all files listed
**     update    ->     Insert files that have changed or that were not
**                      previously in the archive
**
** Create the "sqlar" table in the database if it does not already exist.
** Then add each file in the azFile[] array to the archive. Directories
** are added recursively. If argument bVerbose is non-zero, a message is
** printed on stdout for each file archived.
**
** The create command is the same as update, except that it drops
** any existing "sqlar" table before beginning.  The "insert" command
** always overwrites every file named on the command-line, where as
** "update" only overwrites if the size or mtime or mode has changed.
*/
static int arCreateOrUpdateCommand(
  ArCommand *pAr,                 /* Command arguments and options */
  int bUpdate,                    /* true for a --create. */
  int bOnlyIfChanged              /* Only update if file has changed */
){
  const char *zCreate =
      "CREATE TABLE IF NOT EXISTS sqlar(\n"
      "  name TEXT PRIMARY KEY,  -- name of the file\n"
      "  mode INT,               -- access permissions\n"
      "  mtime INT,              -- last modification time\n"
      "  sz INT,                 -- original file size\n"
      "  data BLOB               -- compressed content\n"
      ")";
  const char *zDrop = "DROP TABLE IF EXISTS sqlar";
  const char *zInsertFmt[2] = {
     "REPLACE INTO %s(name,mode,mtime,sz,data)\n"
     "  SELECT\n"
     "    %s,\n"
     "    mode,\n"
     "    mtime,\n"
     "    CASE substr(lsmode(mode),1,1)\n"
     "      WHEN '-' THEN length(data)\n"
     "      WHEN 'd' THEN 0\n"
     "      ELSE -1 END,\n"
     "    sqlar_compress(data)\n"
     "  FROM fsdir(%Q,%Q) AS disk\n"
     "  WHERE lsmode(mode) NOT LIKE '?%%'%s;"
     ,
     "REPLACE INTO %s(name,mode,mtime,data)\n"
     "  SELECT\n"
     "    %s,\n"
     "    mode,\n"
     "    mtime,\n"
     "    data\n"
     "  FROM fsdir(%Q,%Q) AS disk\n"
     "  WHERE lsmode(mode) NOT LIKE '?%%'%s;"
  };
  int i;                          /* For iterating through azFile[] */
  int rc;                         /* Return code */
  const char *zTab = 0;           /* SQL table into which to insert */
  char *zSql;
  char zTemp[50];
  char *zExists = 0;

  arExecSql(pAr, "PRAGMA page_size=512");
  rc = arExecSql(pAr, "SAVEPOINT ar;");
  if( rc!=SQLITE_OK ) return rc;
  zTemp[0] = 0;
  if( pAr->bZip ){
    /* Initialize the zipfile virtual table, if necessary */
    if( pAr->zFile ){
      sqlite3_uint64 r;
      sqlite3_randomness(sizeof(r),&r);
      sqlite3_snprintf(sizeof(zTemp),zTemp,"zip%016llx",r);
      zTab = zTemp;
      zSql = sqlite3_mprintf(
         "CREATE VIRTUAL TABLE temp.%s USING zipfile(%Q)",
         zTab, pAr->zFile
      );
      rc = arExecSql(pAr, zSql);
      sqlite3_free(zSql);
    }else{
      zTab = "zip";
    }
  }else{
    /* Initialize the table for an SQLAR */
    zTab = "sqlar";
    if( bUpdate==0 ){
      rc = arExecSql(pAr, zDrop);
      if( rc!=SQLITE_OK ) goto end_ar_transaction;
    }
    rc = arExecSql(pAr, zCreate);
  }
  if( bOnlyIfChanged ){
    zExists = sqlite3_mprintf(
      " AND NOT EXISTS("
          "SELECT 1 FROM %s AS mem"
          " WHERE mem.name=disk.name"
          " AND mem.mtime=disk.mtime"
          " AND mem.mode=disk.mode)", zTab);
  }else{
    zExists = sqlite3_mprintf("");
  }
  if( zExists==0 ) rc = SQLITE_NOMEM;
  for(i=0; i<pAr->nArg && rc==SQLITE_OK; i++){
    char *zSql2 = sqlite3_mprintf(zInsertFmt[pAr->bZip], zTab,
        pAr->bVerbose ? "shell_putsnl(name)" : "name",
        pAr->azArg[i], pAr->zDir, zExists);
    rc = arExecSql(pAr, zSql2);
    sqlite3_free(zSql2);
  }
end_ar_transaction:
  if( rc!=SQLITE_OK ){
    sqlite3_exec(pAr->db, "ROLLBACK TO ar; RELEASE ar;", 0, 0, 0);
  }else{
    rc = arExecSql(pAr, "RELEASE ar;");
    if( pAr->bZip && pAr->zFile ){
      zSql = sqlite3_mprintf("DROP TABLE %s", zTemp);
      arExecSql(pAr, zSql);
      sqlite3_free(zSql);
    }
  }
  sqlite3_free(zExists);
  return rc;
}

/*
** Implementation of ".ar" dot command.
*/
static int arDotCommand(
  ShellState *pState,          /* Current shell tool state */
  int fromCmdLine,             /* True if -A command-line option, not .ar cmd */
  char **azArg,                /* Array of arguments passed to dot command */
  int nArg                     /* Number of entries in azArg[] */
){
  ArCommand cmd;
  int rc;
  memset(&cmd, 0, sizeof(cmd));
  cmd.fromCmdLine = fromCmdLine;
  rc = arParseCommand(azArg, nArg, &cmd);
  if( rc==SQLITE_OK ){
    int eDbType = SHELL_OPEN_UNSPEC;
    cmd.p = pState;
    cmd.out = pState->out;
    cmd.db = pState->db;
    if( cmd.zFile ){
      eDbType = deduceDatabaseType(cmd.zFile, 1, 0);
    }else{
      eDbType = pState->openMode;
    }
    if( eDbType==SHELL_OPEN_ZIPFILE ){
      if( cmd.eCmd==AR_CMD_EXTRACT || cmd.eCmd==AR_CMD_LIST ){
        if( cmd.zFile==0 ){
          cmd.zSrcTable = sqlite3_mprintf("zip");
        }else{
          cmd.zSrcTable = sqlite3_mprintf("zipfile(%Q)", cmd.zFile);
        }
      }
      cmd.bZip = 1;
    }else if( cmd.zFile ){
      int flags;
      if( cmd.bAppend ) eDbType = SHELL_OPEN_APPENDVFS;
      if( cmd.eCmd==AR_CMD_CREATE || cmd.eCmd==AR_CMD_INSERT
           || cmd.eCmd==AR_CMD_REMOVE || cmd.eCmd==AR_CMD_UPDATE ){
        flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
      }else{
        flags = SQLITE_OPEN_READONLY;
      }
      cmd.db = 0;
      if( cmd.bDryRun ){
        cli_printf(cmd.out, "-- open database '%s'%s\n", cmd.zFile,
              eDbType==SHELL_OPEN_APPENDVFS ? " using 'apndvfs'" : "");
      }
      rc = sqlite3_open_v2(cmd.zFile, &cmd.db, flags,
             eDbType==SHELL_OPEN_APPENDVFS ? "apndvfs" : 0);
      if( rc!=SQLITE_OK ){
        cli_printf(stderr, "cannot open file: %s (%s)\n",
                        cmd.zFile, sqlite3_errmsg(cmd.db));
        goto end_ar_command;
      }
      sqlite3_fileio_init(cmd.db, 0, 0);
      sqlite3_sqlar_init(cmd.db, 0, 0);
      sqlite3_create_function(cmd.db, "shell_putsnl", 1, SQLITE_UTF8, cmd.p,
                              shellPutsFunc, 0, 0);

    }
    if( cmd.zSrcTable==0 && cmd.bZip==0 && cmd.eCmd!=AR_CMD_HELP ){
      if( cmd.eCmd!=AR_CMD_CREATE
       && sqlite3_table_column_metadata(cmd.db,0,"sqlar","name",0,0,0,0,0)
      ){
        cli_printf(stderr, "database does not contain an 'sqlar' table\n");
        rc = SQLITE_ERROR;
        goto end_ar_command;
      }
      cmd.zSrcTable = sqlite3_mprintf("sqlar");
    }

    switch( cmd.eCmd ){
      case AR_CMD_CREATE:
        rc = arCreateOrUpdateCommand(&cmd, 0, 0);
        break;

      case AR_CMD_EXTRACT:
        rc = arExtractCommand(&cmd);
        break;

      case AR_CMD_LIST:
        rc = arListCommand(&cmd);
        break;

      case AR_CMD_HELP:
        arUsage(pState->out);
        break;

      case AR_CMD_INSERT:
        rc = arCreateOrUpdateCommand(&cmd, 1, 0);
        break;

      case AR_CMD_REMOVE:
        rc = arRemoveCommand(&cmd);
        break;

      default:
        assert( cmd.eCmd==AR_CMD_UPDATE );
        rc = arCreateOrUpdateCommand(&cmd, 1, 1);
        break;
    }
  }
end_ar_command:
  if( cmd.db!=pState->db ){
    close_db(cmd.db);
  }
  sqlite3_free(cmd.zSrcTable);

  return rc;
}
/* End of the ".archive" or ".ar" command logic
*******************************************************************************/
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB) */

#if SQLITE_SHELL_HAVE_RECOVER

/*
** This function is used as a callback by the recover extension. Simply
** print the supplied SQL statement to stdout.
*/
static int recoverSqlCb(void *pCtx, const char *zSql){
  ShellState *pState = (ShellState*)pCtx;
  cli_printf(pState->out, "%s;\n", zSql);
  return SQLITE_OK;
}

/*
** This function is called to recover data from the database. A script
** to construct a new database containing all recovered data is output
** on stream pState->out.
*/
static int recoverDatabaseCmd(ShellState *pState, int nArg, char **azArg){
  int rc = SQLITE_OK;
  const char *zRecoveryDb = "";   /* Name of "recovery" database.  Debug only */
  const char *zLAF = "lost_and_found";
  int bFreelist = 1;              /* 0 if --ignore-freelist is specified */
  int bRowids = 1;                /* 0 if --no-rowids */
  sqlite3_recover *p = 0;
  int i = 0;

  for(i=1; i<nArg; i++){
    char *z = azArg[i];
    int n;
    if( z[0]=='-' && z[1]=='-' ) z++;
    n = strlen30(z);
    if( n<=17 && memcmp("-ignore-freelist", z, n)==0 ){
      bFreelist = 0;
    }else
    if( n<=12 && memcmp("-recovery-db", z, n)==0 && i<(nArg-1) ){
      /* This option determines the name of the ATTACH-ed database used
      ** internally by the recovery extension.  The default is "" which
      ** means to use a temporary database that is automatically deleted
      ** when closed.  This option is undocumented and might disappear at
      ** any moment. */
      i++;
      zRecoveryDb = azArg[i];
    }else
    if( n<=15 && memcmp("-lost-and-found", z, n)==0 && i<(nArg-1) ){
      i++;
      zLAF = azArg[i];
    }else
    if( n<=10 && memcmp("-no-rowids", z, n)==0 ){
      bRowids = 0;
    }
    else{
      cli_printf(stderr,"unexpected option: %s\n", azArg[i]);
      showHelp(pState->out, azArg[0]);
      return 1;
    }
  }

  p = sqlite3_recover_init_sql(
      pState->db, "main", recoverSqlCb, (void*)pState
  );

  if( !pState->bSafeMode ){
    sqlite3_recover_config(p, 789, (void*)zRecoveryDb);  /* Debug use only */
  }
  sqlite3_recover_config(p, SQLITE_RECOVER_LOST_AND_FOUND, (void*)zLAF);
  sqlite3_recover_config(p, SQLITE_RECOVER_ROWIDS, (void*)&bRowids);
  sqlite3_recover_config(p, SQLITE_RECOVER_FREELIST_CORRUPT,(void*)&bFreelist);

  cli_printf(pState->out, ".dbconfig defensive off\n");
  sqlite3_recover_run(p);
  if( sqlite3_recover_errcode(p)!=SQLITE_OK ){
    const char *zErr = sqlite3_recover_errmsg(p);
    int errCode = sqlite3_recover_errcode(p);
    cli_printf(stderr,"sql error: %s (%d)\n", zErr, errCode);
  }
  rc = sqlite3_recover_finish(p);
  return rc;
}
#endif /* SQLITE_SHELL_HAVE_RECOVER */

/*
** Implementation of ".intck STEPS_PER_UNLOCK" command.
*/
static int intckDatabaseCmd(ShellState *pState, i64 nStepPerUnlock){
  sqlite3_intck *p = 0;
  int rc = SQLITE_OK;

  rc = sqlite3_intck_open(pState->db, "main", &p);
  if( rc==SQLITE_OK ){
    i64 nStep = 0;
    i64 nError = 0;
    const char *zErr = 0;
    while( SQLITE_OK==sqlite3_intck_step(p) ){
      const char *zMsg = sqlite3_intck_message(p);
      if( zMsg ){
        cli_printf(pState->out, "%s\n", zMsg);
        nError++;
      }
      nStep++;
      if( nStepPerUnlock && (nStep % nStepPerUnlock)==0 ){
        sqlite3_intck_unlock(p);
      }
    }
    rc = sqlite3_intck_error(p, &zErr);
    if( zErr ){
      cli_printf(stderr,"%s\n", zErr);
    }
    sqlite3_intck_close(p);

    cli_printf(pState->out, "%lld steps, %lld errors\n", nStep, nError);
  }

  return rc;
}

/*
 * zAutoColumn(zCol, &db, ?) => Maybe init db, add column zCol to it.
 * zAutoColumn(0, &db, ?) => (db!=0) Form columns spec for CREATE TABLE,
 *   close db and set it to 0, and return the columns spec, to later
 *   be sqlite3_free()'ed by the caller.
 * The return is 0 when either:
 *   (a) The db was not initialized and zCol==0 (There are no columns.)
 *   (b) zCol!=0  (Column was added, db initialized as needed.)
 * The 3rd argument, pRenamed, references an out parameter. If the
 * pointer is non-zero, its referent will be set to a summary of renames
 * done if renaming was necessary, or set to 0 if none was done. The out
 * string (if any) must be sqlite3_free()'ed by the caller.
 */
#ifdef SHELL_DEBUG
#define rc_err_oom_die(rc) \
  if( rc==SQLITE_NOMEM ) shell_check_oom(0); \
  else if(!(rc==SQLITE_OK||rc==SQLITE_DONE)) \
    cli_printf(stderr,"E:%d\n",rc), assert(0)
#else
static void rc_err_oom_die(int rc){
  if( rc==SQLITE_NOMEM ) shell_check_oom(0);
  assert(rc==SQLITE_OK||rc==SQLITE_DONE);
}
#endif

#ifdef SHELL_COLFIX_DB /* If this is set, the DB can be in a file. */
static char zCOL_DB[] = SHELL_STRINGIFY(SHELL_COLFIX_DB);
#else  /* Otherwise, memory is faster/better for the transient DB. */
static const char *zCOL_DB = ":memory:";
#endif

/* Define character (as C string) to separate generated column ordinal
 * from protected part of incoming column names. This defaults to "_"
 * so that incoming column identifiers that did not need not be quoted
 * remain usable without being quoted. It must be one character.
 */
#ifndef SHELL_AUTOCOLUMN_SEP
# define AUTOCOLUMN_SEP "_"
#else
# define AUTOCOLUMN_SEP SHELL_STRINGIFY(SHELL_AUTOCOLUMN_SEP)
#endif

static char *zAutoColumn(const char *zColNew, sqlite3 **pDb, char **pzRenamed){
  /* Queries and D{D,M}L used here */
  static const char * const zTabMake = "\
CREATE TABLE ColNames(\
 cpos INTEGER PRIMARY KEY,\
 name TEXT, nlen INT, chop INT, reps INT, suff TEXT);\
CREATE VIEW RepeatedNames AS \
SELECT DISTINCT t.name FROM ColNames t \
WHERE t.name COLLATE NOCASE IN (\
 SELECT o.name FROM ColNames o WHERE o.cpos<>t.cpos\
);\
";
  static const char * const zTabFill = "\
INSERT INTO ColNames(name,nlen,chop,reps,suff)\
 VALUES(iif(length(?1)>0,?1,'?'),max(length(?1),1),0,0,'')\
";
  static const char * const zHasDupes = "\
SELECT count(DISTINCT (substring(name,1,nlen-chop)||suff) COLLATE NOCASE)\
 <count(name) FROM ColNames\
";
#ifdef SHELL_COLUMN_RENAME_CLEAN
  static const char * const zDedoctor = "\
UPDATE ColNames SET chop=iif(\
  (substring(name,nlen,1) BETWEEN '0' AND '9')\
  AND (rtrim(name,'0123456790') glob '*"AUTOCOLUMN_SEP"'),\
 nlen-length(rtrim(name, '"AUTOCOLUMN_SEP"0123456789')),\
 0\
)\
";
#endif
  static const char * const zSetReps = "\
UPDATE ColNames AS t SET reps=\
(SELECT count(*) FROM ColNames d \
 WHERE substring(t.name,1,t.nlen-t.chop)=substring(d.name,1,d.nlen-d.chop)\
 COLLATE NOCASE\
)\
";
#ifdef SQLITE_ENABLE_MATH_FUNCTIONS
  static const char * const zColDigits = "\
SELECT CAST(ceil(log(count(*)+0.5)) AS INT) FROM ColNames \
";
#else
  /* Counting on SQLITE_MAX_COLUMN < 100,000 here. (32767 is the hard limit.) */
  static const char * const zColDigits = "\
SELECT CASE WHEN (nc < 10) THEN 1 WHEN (nc < 100) THEN 2 \
 WHEN (nc < 1000) THEN 3 WHEN (nc < 10000) THEN 4 \
 ELSE 5 FROM (SELECT count(*) AS nc FROM ColNames) \
";
#endif
  static const char * const zRenameRank =
#ifdef SHELL_COLUMN_RENAME_CLEAN
    "UPDATE ColNames AS t SET suff="
    "iif(reps>1, printf('%c%0*d', '"AUTOCOLUMN_SEP"', $1, cpos), '')"
#else /* ...RENAME_MINIMAL_ONE_PASS */
"WITH Lzn(nlz) AS (" /* Find minimum extraneous leading 0's for uniqueness */
"  SELECT 0 AS nlz"
"  UNION"
"  SELECT nlz+1 AS nlz FROM Lzn"
"  WHERE EXISTS("
"   SELECT 1"
"   FROM ColNames t, ColNames o"
"   WHERE"
"    iif(t.name IN (SELECT * FROM RepeatedNames),"
"     printf('%s"AUTOCOLUMN_SEP"%s',"
"      t.name, substring(printf('%.*c%0.*d',nlz+1,'0',$1,t.cpos),2)),"
"     t.name"
"    )"
"    ="
"    iif(o.name IN (SELECT * FROM RepeatedNames),"
"     printf('%s"AUTOCOLUMN_SEP"%s',"
"      o.name, substring(printf('%.*c%0.*d',nlz+1,'0',$1,o.cpos),2)),"
"     o.name"
"    )"
"    COLLATE NOCASE"
"    AND o.cpos<>t.cpos"
"   GROUP BY t.cpos"
"  )"
") UPDATE Colnames AS t SET"
" chop = 0," /* No chopping, never touch incoming names. */
" suff = iif(name IN (SELECT * FROM RepeatedNames),"
"  printf('"AUTOCOLUMN_SEP"%s', substring("
"   printf('%.*c%0.*d',(SELECT max(nlz) FROM Lzn)+1,'0',1,t.cpos),2)),"
"  ''"
" )"
#endif
    ;
  static const char * const zCollectVar = "\
SELECT\
 '('||x'0a'\
 || group_concat(\
  cname||' ANY',\
  ','||iif((cpos-1)%4>0, ' ', x'0a'||' '))\
 ||')' AS ColsSpec \
FROM (\
 SELECT cpos, printf('\"%w\"',printf('%!.*s%s', nlen-chop,name,suff)) AS cname \
 FROM ColNames ORDER BY cpos\
)";
  static const char * const zRenamesDone =
    "SELECT group_concat("
    " printf('\"%w\" to \"%w\"',name,printf('%!.*s%s', nlen-chop, name, suff)),"
    " ','||x'0a')"
    "FROM ColNames WHERE suff<>'' OR chop!=0"
    ;
  int rc;
  sqlite3_stmt *pStmt = 0;
  assert(pDb!=0);
  if( zColNew ){
    /* Add initial or additional column. Init db if necessary. */
    if( *pDb==0 ){
      if( SQLITE_OK!=sqlite3_open(zCOL_DB, pDb) ) return 0;
#ifdef SHELL_COLFIX_DB
      if(*zCOL_DB!=':')
        sqlite3_exec(*pDb,"drop table if exists ColNames;"
                     "drop view if exists RepeatedNames;",0,0,0);
#endif
#undef SHELL_COLFIX_DB
      rc = sqlite3_exec(*pDb, zTabMake, 0, 0, 0);
      rc_err_oom_die(rc);
    }
    assert(*pDb!=0);
    rc = sqlite3_prepare_v2(*pDb, zTabFill, -1, &pStmt, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_bind_text(pStmt, 1, zColNew, -1, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_step(pStmt);
    rc_err_oom_die(rc);
    sqlite3_finalize(pStmt);
    return 0;
  }else if( *pDb==0 ){
    return 0;
  }else{
    /* Formulate the columns spec, close the DB, zero *pDb. */
    char *zColsSpec = 0;
    int hasDupes = db_int(*pDb, "%s", zHasDupes);
    int nDigits = (hasDupes)? db_int(*pDb, "%s", zColDigits) : 0;
    if( hasDupes ){
#ifdef SHELL_COLUMN_RENAME_CLEAN
      rc = sqlite3_exec(*pDb, zDedoctor, 0, 0, 0);
      rc_err_oom_die(rc);
#endif
      rc = sqlite3_exec(*pDb, zSetReps, 0, 0, 0);
      rc_err_oom_die(rc);
      rc = sqlite3_prepare_v2(*pDb, zRenameRank, -1, &pStmt, 0);
      rc_err_oom_die(rc);
      sqlite3_bind_int(pStmt, 1, nDigits);
      rc = sqlite3_step(pStmt);
      sqlite3_finalize(pStmt);
      if( rc!=SQLITE_DONE ) rc_err_oom_die(SQLITE_NOMEM);
    }
    assert(db_int(*pDb, "%s", zHasDupes)==0); /* Consider: remove this */
    rc = sqlite3_prepare_v2(*pDb, zCollectVar, -1, &pStmt, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_step(pStmt);
    if( rc==SQLITE_ROW ){
      zColsSpec = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
    }else{
      zColsSpec = 0;
    }
    if( pzRenamed!=0 ){
      if( !hasDupes ) *pzRenamed = 0;
      else{
        sqlite3_finalize(pStmt);
        if( SQLITE_OK==sqlite3_prepare_v2(*pDb, zRenamesDone, -1, &pStmt, 0)
            && SQLITE_ROW==sqlite3_step(pStmt) ){
          *pzRenamed = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
        }else
          *pzRenamed = 0;
      }
    }
    sqlite3_finalize(pStmt);
    sqlite3_close(*pDb);
    *pDb = 0;
    return zColsSpec;
  }
}

/*
** Check if the sqlite_schema table contains one or more virtual tables. If
** parameter zLike is not NULL, then it is an SQL expression that the
** sqlite_schema row must also match. If one or more such rows are found,
** print the following warning to the output:
**
** WARNING: Script requires that SQLITE_DBCONFIG_DEFENSIVE be disabled
*/
static int outputDumpWarning(ShellState *p, const char *zLike){
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = 0;
  shellPreparePrintf(p->db, &rc, &pStmt,
    "SELECT 1 FROM sqlite_schema o WHERE "
    "sql LIKE 'CREATE VIRTUAL TABLE%%' AND (%s)", zLike ? zLike : "true"
  );
  if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
    cli_puts("/* WARNING: "
          "Script requires that SQLITE_DBCONFIG_DEFENSIVE be disabled */\n",
          p->out
    );
  }
  shellFinalize(&rc, pStmt);
  return rc;
}

/*
** Fault-Simulator state and logic.
*/
static struct {
  int iId;           /* ID that triggers a simulated fault.  -1 means "any" */
  int iErr;          /* The error code to return on a fault */
  int iCnt;          /* Trigger the fault only if iCnt is already zero */
  int iInterval;     /* Reset iCnt to this value after each fault */
  int eVerbose;      /* When to print output */
  int nHit;          /* Number of hits seen so far */
  int nRepeat;       /* Turn off after this many hits.  0 for never */
  int nSkip;         /* Skip this many before first fault */
} faultsim_state = {-1, 0, 0, 0, 0, 0, 0, 0};

/*
** This is the fault-sim callback
*/
static int faultsim_callback(int iArg){
  if( faultsim_state.iId>0 && faultsim_state.iId!=iArg ){
    return SQLITE_OK;
  }
  if( faultsim_state.iCnt ){
    if( faultsim_state.iCnt>0 ) faultsim_state.iCnt--;
    if( faultsim_state.eVerbose>=2 ){
      cli_printf(stdout, 
         "FAULT-SIM id=%d no-fault (cnt=%d)\n", iArg, faultsim_state.iCnt);
    }
    return SQLITE_OK;
  }
  if( faultsim_state.eVerbose>=1 ){
    cli_printf(stdout, 
         "FAULT-SIM id=%d returns %d\n", iArg, faultsim_state.iErr);
  }
  faultsim_state.iCnt = faultsim_state.iInterval;
  faultsim_state.nHit++;
  if( faultsim_state.nRepeat>0 && faultsim_state.nRepeat<=faultsim_state.nHit ){
    faultsim_state.iCnt = -1;
  }
  return faultsim_state.iErr;
}

/*
** pickStr(zArg, &zErr, zS1, zS2, ..., "");
**
** Try to match zArg against zS1, zS2, and so forth until the first
** emptry string.  Return the index of the match or -1 if none is found.
** If no match is found, and &zErr is not NULL, then write into
** zErr a message describing the valid choices.
*/
static int pickStr(const char *zArg, char **pzErr, ...){
  int i, n;
  const char *z;
  sqlite3_str *pMsg;
  va_list ap;
  va_start(ap, pzErr);
  i = 0;
  while( (z = va_arg(ap,const char*))!=0 && z[0]!=0 ){
    if( cli_strcmp(zArg, z)==0 ) return i;
    i++;
  }
  va_end(ap);
  if( pzErr==0 ) return -1;
  n = i;
  pMsg = sqlite3_str_new(0);
  va_start(ap, pzErr);
  sqlite3_str_appendall(pMsg, "should be");
  i = 0;
  while( (z = va_arg(ap, const char*))!=0 && z[0]!=0 ){
    if( i==n-1 ){
      sqlite3_str_append(pMsg,", or",4);
    }else if( i>0 ){
      sqlite3_str_append(pMsg, ",", 1);
    }
    sqlite3_str_appendf(pMsg, " %s", z);
    i++;
  }
  va_end(ap);
  *pzErr = sqlite3_str_finish(pMsg);
  return -1;
}

/*
** DOT-COMMAND: .import
**
** USAGE: .import [OPTIONS] FILE TABLE
**
** Import CSV or similar text from FILE into TABLE.  If TABLE does
** not exist, it is created using the first row of FILE as the column
** names.  If FILE begins with "|" then it is a command that is run
** and the output from the command is used as the input data.  If
** FILE begins with "<<" followed by a label, then content is read from
** the script until the first line that matches the label.
**
** The content of FILE is interpreted using RFC-4180 ("CSV") quoting
** rules unless the current mode is "ascii" or "tabs" or unless one
** the --ascii option is used.
**
** The column and row separators must be single ASCII characters.  If
** multiple characters or a Unicode character are specified for the
** separators, then only the first byte of the separator is used.  Except,
** if the row separator is \n and the mode is not --ascii, then \r\n is
** understood as a row separator too.
**
** Options:
**   --ascii         Do not use RFC-4180 quoting.  Use \037 and \036
**                   as column and row separators on input, unless other
**                   delimiters are specified using --colsep and/or --rowsep
**   --colsep CHAR   Use CHAR as the column separator.
**   --csv           Input is standard RFC-4180 CSV.
**   --esc CHAR      Use CHAR as an escape character in unquoted CSV inputs.
**   --qesc CHAR     Use CHAR as an escape character in quoted CSV inputs.
**   --rowsep CHAR   Use CHAR as the row separator.
**   --schema S      When creating TABLE, put it in schema S
**   --skip N        Ignore the first N rows of input
**   -v              Verbose mode
*/
static int dotCmdImport(ShellState *p){
  int nArg = p->dot.nArg;     /* Number of arguments */
  char **azArg = p->dot.azArg;/* Argument list */
  char *zTable = 0;           /* Insert data into this table */
  char *zSchema = 0;          /* Schema of zTable */
  char *zFile = 0;            /* Name of file to extra content from */
  sqlite3_stmt *pStmt = NULL; /* A statement */
  int nCol;                   /* Number of columns in the table */
  i64 nByte;                  /* Number of bytes in an SQL string */
  int i, j;                   /* Loop counters */
  int needCommit;             /* True to COMMIT or ROLLBACK at end */
  char *zSql = 0;             /* An SQL statement */
  ImportCtx sCtx;             /* Reader context */
  char *(SQLITE_CDECL *xRead)(ImportCtx*); /* Func to read one value */
  int eVerbose = 0;           /* Larger for more console output */
  i64 nSkip = 0;              /* Initial lines to skip */
  i64 iLineOffset = 0;        /* Offset to the first line of input */
  char *zCreate = 0;          /* CREATE TABLE statement text */
  int rc;                     /* Result code */

  failIfSafeMode(p, "cannot run .import in safe mode");
  memset(&sCtx, 0, sizeof(sCtx));
  if( p->mode.eMode==MODE_Ascii ){
    xRead = ascii_read_one_field;
  }else{
    xRead = csv_read_one_field;
  }
  for(i=1; i<nArg; i++){
    char *z = azArg[i];
    if( z[0]=='-' && z[1]=='-' ) z++;
    if( z[0]!='-' ){
      if( zFile==0 ){
        zFile = z;
      }else if( zTable==0 ){
        zTable = z;
      }else{
        dotCmdError(p, i, "unknown argument", 0);
        return 1;
      }
    }else if( cli_strcmp(z,"-v")==0 ){
      eVerbose++;
    }else if( cli_strcmp(z,"-schema")==0 && i<nArg-1 ){
      zSchema = azArg[++i];
    }else if( cli_strcmp(z,"-skip")==0 && i<nArg-1 ){
      nSkip = integerValue(azArg[++i]);
    }else if( cli_strcmp(z,"-ascii")==0 ){
      if( sCtx.cColSep==0 ) sCtx.cColSep = SEP_Unit[0];
      if( sCtx.cRowSep==0 ) sCtx.cRowSep = SEP_Record[0];
      xRead = ascii_read_one_field;
    }else if( cli_strcmp(z,"-csv")==0 ){
      if( sCtx.cColSep==0 ) sCtx.cColSep = ',';
      if( sCtx.cRowSep==0 ) sCtx.cRowSep = '\n';
      xRead = csv_read_one_field;
    }else if( cli_strcmp(z,"-esc")==0 ){
      sCtx.cUQEscape = azArg[++i][0];
    }else if( cli_strcmp(z,"-qesc")==0 ){
      sCtx.cQEscape = azArg[++i][0];
    }else if( cli_strcmp(z,"-colsep")==0 ){
      if( i==nArg-1 ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      i++;
      sCtx.cColSep = azArg[i][0];
    }else if( cli_strcmp(z,"-rowsep")==0 ){
      if( i==nArg-1 ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      i++;
      sCtx.cRowSep = azArg[i][0];
    }else{
      dotCmdError(p, i, "unknown option", 0);
      return 1;
    }
  }
  if( zTable==0 ){
    dotCmdError(p, nArg, 0, "Missing %s argument\n",
          zFile==0 ? "FILE" : "TABLE");
    return 1;
  }
  seenInterrupt = 0;
  open_db(p, 0);
  if( sCtx.cColSep==0 ){
    if( p->mode.spec.zColumnSep && p->mode.spec.zColumnSep[0]!=0 ){
      sCtx.cColSep = p->mode.spec.zColumnSep[0];
    }else{
      sCtx.cColSep = ',';
    }
  }
  if( (sCtx.cColSep & 0x80)!=0 ){
    eputz("Error: .import column separator must be ASCII\n");
    return 1;
  }
  if( sCtx.cRowSep==0 ){
    if( p->mode.spec.zRowSep && p->mode.spec.zRowSep[0]!=0 ){
      sCtx.cRowSep = p->mode.spec.zRowSep[0];
    }else{
      sCtx.cRowSep = '\n';
    }
  }
  if( sCtx.cRowSep=='\r' && xRead!=ascii_read_one_field ){
    sCtx.cRowSep = '\n';
  }
  if( (sCtx.cRowSep & 0x80)!=0 ){
    eputz("Error: .import row separator must be ASCII\n");
    return 1;
  }
  sCtx.zFile = zFile;
  sCtx.nLine = 1;
  if( sCtx.zFile[0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
    eputz("Error: pipes are not supported in this OS\n");
    return 1;
#else
    sCtx.in = sqlite3_popen(sCtx.zFile+1, "r");
    sCtx.zFile = "<pipe>";
    sCtx.xCloser = pclose;
#endif
  }else if( sCtx.zFile[0]=='<' && sCtx.zFile[1]=='<' && sCtx.zFile[2]!=0 ){
    /* Input text comes from subsequent lines of script until the zFile
    ** delimiter */
    int nEndMark = strlen30(zFile)-2;
    char *zEndMark = &zFile[2];
    sqlite3_str *pContent = sqlite3_str_new(p->db);
    int ckEnd = 1;
    i64 iStart = p->lineno;
    char zLine[2000];
    sCtx.zFile = p->zInFile;
    sCtx.nLine = p->lineno+1;
    iLineOffset = p->lineno;
    while( sqlite3_fgets(zLine,sizeof(zLine),p->in) ){
      if( ckEnd && cli_strncmp(zLine,zEndMark,nEndMark)==0 ){
        ckEnd = 2;
        if( strchr(zLine,'\n') ) p->lineno++;
        break;
      }
      if( strchr(zLine,'\n') ){
        p->lineno++;
        ckEnd = 1;
      }else{
        ckEnd = 0;
      }
      sqlite3_str_appendall(pContent, zLine);
    }
    sCtx.zIn = sqlite3_str_finish(pContent);
    if( sCtx.zIn==0 ){
      sCtx.zIn = sqlite3_mprintf("");
    }
    if( ckEnd<2 ){
      i64 savedLn = p->lineno;
      p->lineno = iStart;
      dotCmdError(p, 0, 0,"Content terminator \"%s\" not found.",zEndMark);
      p->lineno = savedLn;
      import_cleanup(&sCtx);
      return 1;
    }
  }else{
    sCtx.in = sqlite3_fopen(sCtx.zFile, "rb");
    sCtx.xCloser = fclose;
  }
  if( sCtx.in==0 && sCtx.zIn==0 ){
    dotCmdError(p, 0, 0, "cannot open \"%s\"", zFile);
    import_cleanup(&sCtx);
    return 1;
  }
  if( eVerbose>=1 ){
    char zSep[2];
    zSep[1] = 0;
    zSep[0] = sCtx.cColSep;
    cli_puts("Column separator ", p->out);
    output_c_string(p->out, zSep);
    cli_puts(", row separator ", p->out);
    zSep[0] = sCtx.cRowSep;
    output_c_string(p->out, zSep);
    cli_puts("\n", p->out);
  }
  sCtx.z = sqlite3_malloc64(120);
  if( sCtx.z==0 ){
    import_cleanup(&sCtx);
    shell_out_of_memory();
  }
  /* Below, resources must be freed before exit. */
  while( nSkip>0 ){
    nSkip--;
    while( xRead(&sCtx) && sCtx.cTerm==sCtx.cColSep ){}
  }
  import_append_char(&sCtx, 0);    /* To ensure sCtx.z is allocated */
  if( sqlite3_table_column_metadata(p->db, zSchema, zTable,0,0,0,0,0,0) 
   && 0==db_int(p->db, "SELECT count(*) FROM \"%w\".sqlite_schema"
                       " WHERE name=%Q AND type='view'",
                       zSchema ? zSchema : "main", zTable)
  ){
    /* Table does not exist.  Create it. */
    sqlite3 *dbCols = 0;
    char *zRenames = 0;
    char *zColDefs;
    zCreate = sqlite3_mprintf("CREATE TABLE \"%w\".\"%w\"", 
                  zSchema ? zSchema : "main", zTable);
    while( xRead(&sCtx) ){
      zAutoColumn(sCtx.z, &dbCols, 0);
      if( sCtx.cTerm!=sCtx.cColSep ) break;
    }
    zColDefs = zAutoColumn(0, &dbCols, &zRenames);
    if( zRenames!=0 ){
      cli_printf((stdin_is_interactive && p->in==stdin)? p->out : stderr,
            "Columns renamed during .import %s due to duplicates:\n"
            "%s\n", sCtx.zFile, zRenames);
      sqlite3_free(zRenames);
    }
    assert(dbCols==0);
    if( zColDefs==0 ){
      cli_printf(stderr,"%s: empty file\n", sCtx.zFile);
      import_cleanup(&sCtx);
      sqlite3_free(zCreate);
      return 1;
    }
    zCreate = sqlite3_mprintf("%z%z\n", zCreate, zColDefs);
    if( zCreate==0 ){
      import_cleanup(&sCtx);
      shell_out_of_memory();
    }
    if( eVerbose>=1 ){
      cli_printf(p->out, "%s\n", zCreate);
    }
    rc = sqlite3_exec(p->db, zCreate, 0, 0, 0);
    if( rc ){
      cli_printf(stderr,
           "%s failed:\n%s\n", zCreate, sqlite3_errmsg(p->db));
    }
    sqlite3_free(zCreate);
    zCreate = 0;
    if( rc ){
      import_cleanup(&sCtx);
      return 1;
    }
  }
  zSql = sqlite3_mprintf("SELECT count(*) FROM pragma_table_info(%Q,%Q);",
                         zTable, zSchema);
  if( zSql==0 ){
    import_cleanup(&sCtx);
    shell_out_of_memory();
  }
  rc =  sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  zSql = 0;
  if( rc ){
    if (pStmt) sqlite3_finalize(pStmt);
    shellDatabaseError(p->db);
    import_cleanup(&sCtx);
    return 1;
  }
  if( sqlite3_step(pStmt)==SQLITE_ROW ){
    nCol = sqlite3_column_int(pStmt, 0);
  }else{
    nCol = 0;
  }
  sqlite3_finalize(pStmt);
  pStmt = 0;
  if( nCol==0 ) return 0; /* no columns, no error */

  nByte = 64                 /* space for "INSERT INTO", "VALUES(", ")\0" */
        + (zSchema ? strlen(zSchema)*2 + 2: 0)  /* Quoted schema name */
        + strlen(zTable)*2 + 2                  /* Quoted table name */
        + nCol*2;            /* Space for ",?" for each column */
  zSql = sqlite3_malloc64( nByte );
  if( zSql==0 ){
    import_cleanup(&sCtx);
    shell_out_of_memory();
  }
  if( zSchema ){
    sqlite3_snprintf(nByte, zSql, "INSERT INTO \"%w\".\"%w\" VALUES(?", 
                     zSchema, zTable);
  }else{
    sqlite3_snprintf(nByte, zSql, "INSERT INTO \"%w\" VALUES(?", zTable);
  }
  j = strlen30(zSql);
  for(i=1; i<nCol; i++){
    zSql[j++] = ',';
    zSql[j++] = '?';
  }
  zSql[j++] = ')';
  zSql[j] = 0;
  assert( j<nByte );
  if( eVerbose>=2 ){
    cli_printf(p->out, "Insert using: %s\n", zSql);
  }
  rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  zSql = 0;
  if( rc ){
    shellDatabaseError(p->db);
    if (pStmt) sqlite3_finalize(pStmt);
    import_cleanup(&sCtx);
    return 1;
  }
  needCommit = sqlite3_get_autocommit(p->db);
  if( needCommit ) sqlite3_exec(p->db, "BEGIN", 0, 0, 0);
  do{
    int startLine = sCtx.nLine;
    for(i=0; i<nCol; i++){
      char *z = xRead(&sCtx);
      /*
      ** Did we reach end-of-file before finding any columns?
      ** If so, stop instead of NULL filling the remaining columns.
      */
      if( z==0 && i==0 ) break;
      /*
      ** Did we reach end-of-file OR end-of-line before finding any
      ** columns in ASCII mode?  If so, stop instead of NULL filling
      ** the remaining columns.
      */
      if( p->mode.eMode==MODE_Ascii && (z==0 || z[0]==0) && i==0 ) break;
      /*
      ** For CSV mode, per RFC 4180, accept EOF in lieu of final
      ** record terminator but only for last field of multi-field row.
      ** (If there are too few fields, it's not valid CSV anyway.)
      */
      if( z==0 && (xRead==csv_read_one_field) && i==nCol-1 && i>0 ){
        z = "";
      }
      sqlite3_bind_text(pStmt, i+1, z, -1, SQLITE_TRANSIENT);
      if( i<nCol-1 && sCtx.cTerm!=sCtx.cColSep ){
        if( i==0 && (strcmp(z,"\n")==0 || strcmp(z,"\r\n")==0) ){
          /* Ignore trailing \n or \r\n when some other row separator */
          break;
        }
        cli_printf(stderr,"%s:%d: expected %d columns but found %d"
              " - filling the rest with NULL\n",
              sCtx.zFile, startLine, nCol, i+1);
        i += 2;
        while( i<=nCol ){ sqlite3_bind_null(pStmt, i); i++; }
      }
    }
    if( sCtx.cTerm==sCtx.cColSep ){
      do{
        xRead(&sCtx);
        i++;
      }while( sCtx.cTerm==sCtx.cColSep );
      cli_printf(stderr,
            "%s:%d: expected %d columns but found %d - extras ignored\n",
            sCtx.zFile, startLine, nCol, i);
    }
    if( i>=nCol ){
      sqlite3_step(pStmt);
      rc = sqlite3_reset(pStmt);
      if( rc!=SQLITE_OK ){
        cli_printf(stderr,"%s:%d: INSERT failed: %s\n",
              sCtx.zFile, startLine, sqlite3_errmsg(p->db));
        sCtx.nErr++;
        if( bail_on_error ) break;
      }else{
        sCtx.nRow++;
      }
    }
  }while( sCtx.cTerm!=EOF );

  import_cleanup(&sCtx);
  sqlite3_finalize(pStmt);
  if( needCommit ) sqlite3_exec(p->db, "COMMIT", 0, 0, 0);
  if( eVerbose>0 ){
    cli_printf(p->out,
          "Added %d rows with %d errors using %d lines of input\n",
          sCtx.nRow, sCtx.nErr, sCtx.nLine-1-iLineOffset);
  }
  return sCtx.nErr ? 1 : 0;
}


/*
** This function computes what to show the user about the configured
** titles (or column-names).  Output is an integer between 0 and 3:
**
**    0:     The titles do not matter.  Never show anything.
**    1:     Show  "--titles off"
**    2:     Show  "--titles on"
**    3:     Show  "--title VALUE"  where VALUE is an encoding method
**             to use, one of: plain sql csv html tcl json
**
** Inputs are:
**
**    spec.bTitles   (bT)     Whether or not to show the titles
**    spec.eTitle    (eT)     The actual encoding to be used for titles
**    ModeInfo.bHdr  (bH)     Default value for spec.bTitles
**    ModeInfo.eHdr  (eH)     Default value for spec.eTitle
**    bAll                    Whether the -v option is used
*/
static int modeTitleDsply(ShellState *p, int bAll){
  int eMode = p->mode.eMode;
  const ModeInfo *pI = &aModeInfo[eMode];
  int bT = p->mode.spec.bTitles;
  int eT = p->mode.spec.eTitle;
  int bH = pI->bHdr;
  int eH = pI->eHdr;

  /* Variable "v" is the truth table that will determine the answer
  **
  **                   Actual encoding is different from default 
  **                            vvvvvvvv                                    */
  sqlite3_uint64 v = UINT64_C(0x0133013311220102);
  /*                            ^^^^    ^^^^
  **                   Upper 2-byte groups for when ON/OFF disagrees with
  **                   the default.                                         */

  if( bH==0 ) return 0;  /* Header not appliable.  Ex: off, count */

  if( eT==0 ) eT = eH;   /* Fill in missing spec.eTitle */
  if( bT==0 ) bT = bH;   /* Fill in missing spec.bTitles */

  if( eT!=eH ) v >>= 32; /* Encoding disagree in upper 4-bytes */
  if( bT!=bH ) v >>= 16; /* ON/OFF disagree in upper 2-byte pairs */
  if( bT<2 ) v >>= 8;    /* ON in even bytes, OFF in odd bytes (1st byte 0) */
  if( !bAll ) v >>= 4;   /* bAll values are in the lower half-byte */

  return v & 3;          /* Return the selected truth-table entry */
}

/*
** DOT-COMMAND:  .mode
**
** USAGE: .mode [MODE] [OPTIONS]
**
** Change the output mode to MODE and/or apply OPTIONS to the output mode.
** Arguments are processed from left to right.  If no arguments, show the
** current output mode and relevant options.
**
** Options:
**   --align STRING           Set the alignment of text in columnar modes
**                            String consists of characters 'L', 'C', 'R'
**                            meaning "left", "centered", and "right", with
**                            one letter per column starting from the left.
**                            Unspecified alignment defaults to 'L'.
**   --blob-quote ARG         ARG can be "auto", "text", "sql", "hex", "tcl",
**                            "json", or "size".  Default is "auto".
**   --border on|off          Show outer border on "box" and "table" modes.
**   --charlimit N            Set the maximum number of output characters to
**                            show for any single SQL value to N. Longer values
**                            truncated. Zero means "no limit".
**   --colsep STRING          Use STRING as the column separator
**   --escape ESC             Enable/disable escaping of control characters
**                            found in the output. ESC can be "off", "ascii",
**                            or "symbol".
**   --linelimit N            Set the maximum number of output lines to show for
**                            any single SQL value to N. Longer values are
**                            truncated. Zero means "no limit". Only works
**                            in "line" mode and in columnar modes.
**   --limits L,C,T           Shorthand for "--linelimit L --charlimit C
**                            --titlelimit T". The ",T" can be omitted in which
**                            case the --titlelimit is unchanged.  The argument
**                            can also be "off" to mean "0,0,0" or "on" to
**                            mean "5,300,20".
**   --list                   List available modes
**   --multiinsert N          In "insert" mode, put multiple rows on a single
**                            INSERT statement until the size exceeds N bytes.
**   --null STRING            Render SQL NULL values as the given string
**   --once                   Setting changes to the right are reverted after
**                            the next SQL command.
**   --quote ARG              Enable/disable quoting of text. ARG can be
**                            "off", "on", "sql", "relaxed", "csv", "html",
**                            "tcl", or "json". "off" means show the text as-is.
**                            "on" is an alias for "sql".
**   --reset                  Changes all mode settings back to their default.
**   --rowsep STRING          Use STRING as the row separator
**   --sw|--screenwidth N     Declare the screen width of the output device
**                            to be N characters.  An attempt may be made to
**                            wrap output text to fit within this limit. Zero
**                            means "no limit".  Or N can be "auto" to set the
**                            width automatically.
**   --tablename NAME         Set the name of the table for "insert" mode.
**   --tag NAME               Save mode to the left as NAME.
**   --textjsonb BOOLEAN      If enabled, JSONB text is displayed as text JSON.
**   --title ARG              Whether or not to show column headers, and if so
**                            how to encode them.  ARG can be "off", "on",
**                            "sql", "csv", "html", "tcl", or "json".
**   --titlelimit N           Limit the length of column titles to N characters.
**   -v|--verbose             Verbose output
**   --widths LIST            Set the columns widths for columnar modes. The
**                            argument is a list of integers, one for each
**                            column. A "0" width means use a dynamic width
**                            based on the actual width of data. If there are
**                            fewer entries in LIST than columns, "0" is used
**                            for the unspecified widths.
**   --wordwrap BOOLEAN       Enable/disable word wrapping
**   --wrap N                 Wrap columns wider than N characters
**   --ww                     Shorthand for "--wordwrap on"
*/
static int dotCmdMode(ShellState *p){
  int nArg = p->dot.nArg;     /* Number of arguments */
  char **azArg = p->dot.azArg;/* Argument list */
  int eMode = -1;             /* New mode value, or -1 for none */
  int iMode = -1;             /* Index of the argument that is the mode name */
  int i;                      /* Loop counter */
  int k;                      /* Misc index variable */
  int chng = 0;               /* True if anything has changed */
  int bAll = 0;               /* Show all details of the mode */

  for(i=1; i<nArg; i++){
    const char *z = azArg[i];
    if( z[0]=='-' && z[1]=='-' ) z++;
    if( z[0]!='-'
     && iMode<0
     && (eMode = modeFind(p, azArg[i]))>=0
     && eMode!=MODE_Www
    ){
      iMode = i;
      modeChange(p, eMode);
      /* (Legacy) If the mode is MODE_Insert and the next argument
      ** is not an option, then the next argument must be the table
      ** name.
      */
      if( i+1<nArg && azArg[i+1][0]!='-' ){
        i++;
        modeSetStr(&p->mode.spec.zTableName, azArg[i]);
      }
      chng = 1;
    }else if( optionMatch(z,"align") ){
      char *zAlign;
      int nAlign;
      int nErr = 0;
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      i++;
      zAlign = azArg[i];
      nAlign = 0x3fff & strlen(zAlign);
      free(p->mode.spec.aAlign);
      p->mode.spec.aAlign = malloc(nAlign);
      shell_check_oom(p->mode.spec.aAlign);
      for(k=0; k<nAlign; k++){
        unsigned char c = 0;
        switch( zAlign[k] ){
          case 'l': case 'L':   c = QRF_ALIGN_Left;   break;
          case 'c': case 'C':   c = QRF_ALIGN_Center; break;
          case 'r': case 'R':   c = QRF_ALIGN_Right;  break;
          default:  nErr++; break;
        }
        p->mode.spec.aAlign[k] = c;
      }
      p->mode.spec.nAlign = nAlign;
      chng = 1;
      if( nErr ){
        dotCmdError(p, i, "bad alignment string",
             "Should contain only characters L, C, and R.");
        return 1;
      }
    }else if( pickStr(z,0,"-blob","-blob-quote","")>=0 ){
      if( (++i)>=nArg ){
        dotCmdError(p, i-1, "missing argument", 0);
        return 1;
      }
      k = pickStr(azArg[i], 0,
                    "auto", "text", "sql", "hex", "tcl", "json", "size", "");
        /*           0       1       2      3      4      5       6
        ** Must match QRF_BLOB_xxxx values.  See also tag-20251124a */
      if( k>=0 ){
        p->mode.spec.eBlob = k & 0xff;
      }
      chng = 1;
    }else if( optionMatch(z,"border") ){
      if( (++i)>=nArg ){
        dotCmdError(p, i-1, "missing argument", 0);
        return 1;
      }
      k = pickStr(azArg[i], 0, "auto", "off", "on", "");
      if( k>=0 ){
        p->mode.spec.bBorder = k & 0x3;
      }
      chng = 1;
    }else if( 0<=(k=pickStr(z,0,
                  "-charlimit","-linelimit","-titlelimit","-multiinsert","")) ){
      int w;   /*  0            1            2             3 */
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      w = integerValue(azArg[++i]);
      switch( k ){
        case 0:   p->mode.spec.nCharLimit = w;    break;
        case 1:   p->mode.spec.nLineLimit = w;    break;
        case 2:   p->mode.spec.nTitleLimit = w;   break;
        default:  p->mode.spec.nMultiInsert = w;  break;
      }
      chng = 1;
    }else if( 0<=(k=pickStr(z,0,"-tablename","-rowsep","-colsep","-null","")) ){
                            /*   0            1         2         3 */
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      i++;
      switch( k ){
        case 0: modeSetStr(&p->mode.spec.zTableName, azArg[i]); break;
        case 1: modeSetStr(&p->mode.spec.zRowSep, azArg[i]);    break;
        case 2: modeSetStr(&p->mode.spec.zColumnSep, azArg[i]); break;
        case 3: modeSetStr(&p->mode.spec.zNull, azArg[i]);      break;
      }
      chng = 1;
    }else if( optionMatch(z,"escape") ){
      /* See similar code at tag-20250224-1 */
      char *zErr = 0;
      if( (++i)>=nArg ){
        dotCmdError(p, i-1, "missing argument", 0);
        return 1;
      }                       /*  0     1       2  <-- One less than QRF_ESC_ */
      k = pickStr(azArg[i],&zErr,"off","ascii","symbol","");
      if( k<0 ){
        dotCmdError(p, i, "unknown escape type", "%s", zErr);
        sqlite3_free(zErr);
        return 1;
      }
      p->mode.spec.eEsc = k+1;
      chng = 1;
    }else if( optionMatch(z,"limits") ){
      if( (++i)>=nArg ){
        dotCmdError(p, i-1, "missing argument", 0);
        return 1;
      }
      k = pickStr(azArg[i],0,"on","off","");
      if( k==0 ){
        p->mode.spec.nLineLimit = DFLT_LINE_LIMIT;
        p->mode.spec.nCharLimit = DFLT_CHAR_LIMIT;
        p->mode.spec.nTitleLimit = DFLT_TITLE_LIMIT;
      }else if( k==1 ){
        p->mode.spec.nLineLimit = 0;
        p->mode.spec.nCharLimit = 0;
        p->mode.spec.nTitleLimit = 0;
      }else{
        int L, C, T = 0;
        int nNum = sscanf(azArg[i], "%d,%d,%d", &L, &C, &T);
        if( nNum<2 || L<0 || C<0 || T<0){
          dotCmdError(p, i, "bad argument", "Should be \"L,C,T\" where L, C"
                            " and T are unsigned integers");
          return 1;
        }        
        p->mode.spec.nLineLimit = L;
        p->mode.spec.nCharLimit = C;
        if( nNum==3 ) p->mode.spec.nTitleLimit = T;
      }
      chng = 1;
    }else if( optionMatch(z,"list") ){
      int ii;
      cli_puts("available modes:", p->out);
      for(ii=0; ii<ArraySize(aModeInfo); ii++){
        if( ii==MODE_Www ) continue;
        cli_printf(p->out, " %s", aModeInfo[ii].zName);
      }
      for(ii=0; ii<p->nSavedModes; ii++){
        cli_printf(p->out, " %s", p->aSavedModes[ii].zTag);
      }
      cli_puts(" batch tty\n", p->out);
      chng = 1;  /* Not really a change, but we still want to suppress the
                 ** "current mode" output */
    }else if( optionMatch(z,"once") ){
      p->nPopMode = 0;
      modePush(p);
      p->nPopMode = 1;
    }else if( optionMatch(z,"noquote") ){
      /* (undocumented legacy) --noquote always turns quoting off */
      p->mode.spec.eText = QRF_TEXT_Plain;
      p->mode.spec.eBlob = QRF_BLOB_Auto;
      chng = 1;
    }else if( optionMatch(z,"quote") ){
      if( i+1<nArg
       && azArg[i+1][0]!='-'
       && (iMode>0 || strcmp(azArg[i+1],"off")==0 || modeFind(p, azArg[i+1])<0)
      ){
        /* --quote is followed by an argument other that is not an option
        ** or a mode name.  See it must be a boolean or a keyword to describe
        ** how to set quoting. */
        i++;
        if( (k = pickStr(azArg[i],0,"no","yes","0","1",""))>=0 ){
          k &= 1;   /* 0 for "off".  1 for "on". */
        }else{
          char *zErr = 0;
          k = pickStr(azArg[i],&zErr,
                 "off","on","sql","csv","html","tcl","json","relaxed","");
              /*  0     1    2     3     4      5     6      7   */
          if( k<0 ){
            dotCmdError(p, i, "unknown", "%z", zErr);
            return 1;
          }
        }
      }else{
        /* (Legacy) no following boolean argument.  Turn quoting on */ 
        k = 1;
      }
      switch( k ){
        case 1:  /* on */
          modeSetStr(&p->mode.spec.zNull, "NULL");
          /* Fall through */
        case 2:  /* sql */
          p->mode.spec.eText = QRF_TEXT_Sql;
          break;
        case 3:  /* csv */
          p->mode.spec.eText = QRF_TEXT_Csv;
          break;
        case 4:  /* html */
          p->mode.spec.eText = QRF_TEXT_Html;
          break;
        case 5:  /* tcl */
          p->mode.spec.eText = QRF_TEXT_Tcl;
          break;
        case 6:  /* json */
          p->mode.spec.eText = QRF_TEXT_Json;
          break;
        case 7:  /* relaxed */
          p->mode.spec.eText = QRF_TEXT_Relaxed;
          break;
        default: /* off */
          p->mode.spec.eText = QRF_TEXT_Plain;
          break;
      }
      chng = 1;
    }else if( optionMatch(z,"reset") ){
      int saved_eMode = p->mode.eMode;
      modeFree(&p->mode);
      modeChange(p, saved_eMode);
    }else if( optionMatch(z,"screenwidth") || optionMatch(z,"sw") ){
      if( (++i)>=nArg ){
        dotCmdError(p, i-1, "missing argument", 0);
        return 1;
      }
      k = pickStr(azArg[i],0,"off","auto","");
      if( k==0 ){
        p->mode.bAutoScreenWidth = 0;
        p->mode.spec.nScreenWidth = 0;
      }else if( k==1 ){
        p->mode.bAutoScreenWidth = 1;
      }else{
        i64 w = integerValue(azArg[i]);
        p->mode.bAutoScreenWidth = 0;
        if( w<0 ) w = 0;
        if( w>QRF_MAX_WIDTH ) w = QRF_MAX_WIDTH;
        p->mode.spec.nScreenWidth = w;
      }
      chng = 1;
    }else if( optionMatch(z,"tag") ){
      size_t nByte;
      int n;
      const char *zTag;
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      zTag = azArg[++i];
      if( modeFind(p, zTag)>=0 ){
        dotCmdError(p, i, "mode already exists", 0);
        return 1;
      }
      if( p->nSavedModes > MODE_N_USER ){
        dotCmdError(p, i-1, "cannot add more modes", 0);
        return 1;
      }
      n = p->nSavedModes++;
      nByte = sizeof(p->aSavedModes[0]);
      nByte *= n+1;
      p->aSavedModes = realloc( p->aSavedModes, nByte );
      shell_check_oom(p->aSavedModes);
      p->aSavedModes[n].zTag = strdup(zTag);
      shell_check_oom(p->aSavedModes[n].zTag);
      modeDup(&p->aSavedModes[n].mode, &p->mode);
      chng = 1;
    }else if( optionMatch(z,"textjsonb") ){
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      p->mode.spec.bTextJsonb = booleanValue(azArg[++i]) ? QRF_Yes : QRF_No;
      chng = 1;
    }else if( optionMatch(z,"titles") || optionMatch(z,"title") ){
      char *zErr = 0;
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      k = pickStr(azArg[++i],&zErr,
              "off","on","plain","sql","csv","html","tcl","json","");
          /*   0     1    2       3     4     5     6      7 */
      if( k<0 ){
        dotCmdError(p, i, "bad --titles value","%z", zErr);
        return 1;
      }
      p->mode.spec.bTitles = k>=1 ? QRF_Yes : QRF_No;
      p->mode.mFlags &= ~MFLG_HDR;
      p->mode.spec.eTitle = k>1 ? k-1 : aModeInfo[p->mode.eMode].eHdr;
      chng = 1;
    }else if( optionMatch(z,"widths") || optionMatch(z,"width") ){
      int nWidth = 0;
      short int *aWidth;
      const char *zW;
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      zW = azArg[++i];
      /* Every width value takes at least 2 bytes in the input string to
      ** specify, so strlen(zW) bytes should be plenty of space to hold the
      ** result. */
      aWidth = malloc( strlen(zW) );
      while( IsSpace(zW[0]) ) zW++;
      while( zW[0] ){
        int w = 0;
        int nDigit = 0;
        k = zW[0]=='-' && IsDigit(zW[1]);
        while( IsDigit(zW[k]) ){
          w = w*10 + zW[k] - '0';
          if( w>QRF_MAX_WIDTH ){
            dotCmdError(p,i+1,"width too big",
                        "Maximum column width is %d", QRF_MAX_WIDTH);
            free(aWidth);
            return 1;
          }
          nDigit++;
          k++;
        }
        if( nDigit==0 ){
          dotCmdError(p,i+1,"syntax error",
                      "should be a comma-separated list if integers");
          free(aWidth);
          return 1;
        }
        if( zW[0]=='-' ) w = -w;
        aWidth[nWidth++] = w;
        zW += k;
        if( zW[0]==',' ) zW++;
        while( IsSpace(zW[0]) ) zW++;
      }
      free(p->mode.spec.aWidth);
      p->mode.spec.aWidth = aWidth;
      p->mode.spec.nWidth = nWidth;
      chng = 1;
    }else if( optionMatch(z,"wrap") ){
      int w;
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      w = integerValue(azArg[++i]);
      if( w<(-QRF_MAX_WIDTH) ) w = -QRF_MAX_WIDTH;
      if( w>QRF_MAX_WIDTH ) w = QRF_MAX_WIDTH;
      p->mode.spec.nWrap = w;
      chng = 1;
    }else if( optionMatch(z,"ww") ){
      p->mode.spec.bWordWrap = QRF_Yes;
      chng = 1;
    }else if( optionMatch(z,"wordwrap") ){
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      p->mode.spec.bWordWrap = (u8)booleanValue(azArg[++i]) ? QRF_Yes : QRF_No;
      chng = 1;
    }else if( optionMatch(z,"v") || optionMatch(z,"verbose") ){
      bAll = 1;
    }else if( z[0]=='-' ){
      dotCmdError(p, i, "bad option", "Use \".help .mode\" for more info");
      return 1;
    }else{
      dotCmdError(p, i, iMode>0?"bad argument":"unknown mode",
                  "Use \".help .mode\" for more info");
      return 1;
    }
  }
  if( !chng || bAll ){
    const ModeInfo *pI = aModeInfo + p->mode.eMode;
    sqlite3_str *pDesc = sqlite3_str_new(p->db);
    char *zDesc;
    const char *zSetting;

    if( p->nPopMode ) sqlite3_str_appendall(pDesc, "--once ");
    sqlite3_str_appendall(pDesc,pI->zName);
    if( bAll || (p->mode.spec.nAlign && pI->eCx==2) ){
      int ii;
      sqlite3_str_appendall(pDesc, " --align \"");
      for(ii=0; ii<p->mode.spec.nAlign; ii++){
        unsigned char a = p->mode.spec.aAlign[ii];
        sqlite3_str_appendchar(pDesc, 1, "LLCR"[a&3]);
      }
      sqlite3_str_append(pDesc, "\"", 1);
    }
    if( bAll
     || (p->mode.spec.bBorder==QRF_No) != ((pI->mFlg&1)!=0)
    ){
      sqlite3_str_appendf(pDesc," --border %s",
             p->mode.spec.bBorder==QRF_No ? "off" : "on");
    }
    if( bAll || p->mode.spec.eBlob!=QRF_BLOB_Auto ){
      const char *azBQuote[] =
           { "auto", "text", "sql", "hex", "tcl", "json", "size" };
      /*      0       1       2      3      4      5       6
      ** Must match QRF_BLOB_xxxx values.  See all instances of tag-20251124a */
      u8 e = p->mode.spec.eBlob;
      sqlite3_str_appendf(pDesc, " --blob-quote %s", azBQuote[e]);
    }
    zSetting = aModeStr[pI->eCSep];
    if( bAll || (zSetting && cli_strcmp(zSetting,p->mode.spec.zColumnSep)!=0) ){
      sqlite3_str_appendf(pDesc, " --colsep ");
      append_c_string(pDesc, p->mode.spec.zColumnSep);
    }
    if( bAll || p->mode.spec.eEsc!=QRF_Auto ){
      sqlite3_str_appendf(pDesc, " --escape %s",qrfEscNames[p->mode.spec.eEsc]);
    }
    if( bAll
     || (p->mode.spec.nLineLimit>0 && pI->eCx>0)
     || p->mode.spec.nCharLimit>0
     || (p->mode.spec.nTitleLimit>0 && pI->eCx>0)
    ){
      if( p->mode.spec.nLineLimit==0
       && p->mode.spec.nCharLimit==0
       && p->mode.spec.nTitleLimit==0
      ){
        sqlite3_str_appendf(pDesc, " --limits off");
      }else if( p->mode.spec.nLineLimit==DFLT_LINE_LIMIT
       && p->mode.spec.nCharLimit==DFLT_CHAR_LIMIT
       && p->mode.spec.nTitleLimit==DFLT_TITLE_LIMIT
      ){
        sqlite3_str_appendf(pDesc, " --limits on");
      }else{
        sqlite3_str_appendf(pDesc, " --limits %d,%d,%d",
           p->mode.spec.nLineLimit, p->mode.spec.nCharLimit,
           p->mode.spec.nTitleLimit);
      }
    }
    if( bAll
     || (p->mode.spec.nMultiInsert && p->mode.spec.eStyle==QRF_STYLE_Insert)
    ){
      sqlite3_str_appendf(pDesc, " --multiinsert %u",
                          p->mode.spec.nMultiInsert);
    }
    zSetting = aModeStr[pI->eNull];
    if( bAll || (zSetting && cli_strcmp(zSetting,p->mode.spec.zNull)!=0) ){
      sqlite3_str_appendf(pDesc, " --null ");
      append_c_string(pDesc, p->mode.spec.zNull);
    }
    if( bAll 
     || (pI->eText!=p->mode.spec.eText && (pI->eText>1 || p->mode.spec.eText>1))
    ){
      sqlite3_str_appendf(pDesc," --quote %s",qrfQuoteNames[p->mode.spec.eText]);
    }
    zSetting = aModeStr[pI->eRSep];
    if( bAll || (zSetting && cli_strcmp(zSetting,p->mode.spec.zRowSep)!=0) ){
      sqlite3_str_appendf(pDesc, " --rowsep ");
      append_c_string(pDesc, p->mode.spec.zRowSep);
    }
    if( bAll
     || (pI->eCx && (p->mode.spec.nScreenWidth>0 || p->mode.bAutoScreenWidth))
    ){
      if( p->mode.bAutoScreenWidth ){
        sqlite3_str_appendall(pDesc, " --sw auto");
      }else{
        sqlite3_str_appendf(pDesc," --sw %d",
                            p->mode.spec.nScreenWidth);
      }
    }
    if( bAll || p->mode.eMode==MODE_Insert ){
      sqlite3_str_appendf(pDesc," --tablename ");
      append_c_string(pDesc, p->mode.spec.zTableName);
    }
    if( bAll || p->mode.spec.bTextJsonb ){
      sqlite3_str_appendf(pDesc," --textjsonb %s",
             p->mode.spec.bTextJsonb==QRF_Yes ? "on" : "off");
    }
    k = modeTitleDsply(p, bAll);
    if( k==1 ){
      sqlite3_str_appendall(pDesc, " --titles off");
    }else if( k==2 ){
      sqlite3_str_appendall(pDesc, " --titles on");
    }else if( k==3 ){
      static const char *azTitle[] =
          { "plain", "sql", "csv", "html", "tcl", "json"};
      sqlite3_str_appendf(pDesc, " --titles %s",
                   azTitle[p->mode.spec.eTitle-1]);
    }    
    if( p->mode.spec.nWidth>0 && (bAll || pI->eCx==2) ){
      int ii;
      const char *zSep = " --widths ";
      for(ii=0; ii<p->mode.spec.nWidth; ii++){
        sqlite3_str_appendf(pDesc, "%s%d", zSep, (int)p->mode.spec.aWidth[ii]);
        zSep = ",";
      }
    }else if( bAll ){
      sqlite3_str_appendall(pDesc, " --widths \"\"");
    }
    if( bAll || (pI->eCx>0 && p->mode.spec.bWordWrap) ){
      if( bAll ){
        sqlite3_str_appendf(pDesc, " --wordwrap %s",
          p->mode.spec.bWordWrap==QRF_Yes ? "on" : "off");
      }
      if( p->mode.spec.nWrap ){
        sqlite3_str_appendf(pDesc, " --wrap %d", p->mode.spec.nWrap);
      }
      if( !bAll ) sqlite3_str_append(pDesc, " --ww", 5);
    }
    zDesc = sqlite3_str_finish(pDesc);
    cli_printf(p->out, ".mode %s\n", zDesc);
    fflush(p->out);
    sqlite3_free(zDesc);
  }
  return 0;
}

/*
** DOT-COMMAND: .output
** USAGE: .output [OPTIONS] [FILE]
**
** Begin redirecting output to FILE.  Or if FILE is omitted, revert
** to sending output to the console.  If FILE begins with "|" then
** the remainder of file is taken as a pipe and output is directed
** into that pipe.  If FILE is "memory" then output is captured in an
** internal memory buffer.  If FILE is "off" then output is redirected
** into /dev/null or the equivalent.
**
** Options:
**   --bom             Prepend a byte-order mark to the output
**   -e                Accumulate output in a temporary text file then
**                     launch a text editor when the redirection ends.
**   --error-prefix X  Use X as the left-margin prefix for error messages.
**                     Set to an empty string to restore the default.
**   --keep            Keep redirecting output to its current destination.
**                     Use this option in combination with --show or
**                     with --error-prefix when you do not want to stop
**                     a current redirection.
**   --plain           Use plain text rather than HTML tables with -w
**   --show            Show output text captured by .testcase or by
**                     redirecting to "memory".
**   -w                Show the output in a web browser.  Output is
**                     written into a temporary HTML file until the
**                     redirect ends, then the web browser is launched.
**                     Query results  are shown as HTML tables, unless
**                     the --plain is used too.
**   -x                Show the output in a spreadsheet.  Output is
**                     written to a temp file as CSV then the spreadsheet
**                     is launched when
**
** DOT-COMMAND: .once
** USAGE: .once [OPTIONS] FILE ...
**
** Write the output for the next line of SQL or the next dot-command into
** FILE.  If FILE begins with "|" then it is a program into which output
** is written. The FILE argument should be omitted if one of the -e, -w,
** or -x options is used.
**
** Options:
**   -e                Capture output into a temporary file then bring up
**                     a text editor on that temporary file.
**   --plain           Use plain text rather than HTML tables with -w
**   -w                Capture output into an HTML file then bring up that
**                     file in a web browser
**   -x                Show the output in a spreadsheet.  Output is
**                     written to a temp file as CSV then the spreadsheet
**                     is launched when
**
** DOT-COMMAND: .excel
** Shorthand for ".once -x"
**
** DOT-COMMAND: .www [--plain]
** Shorthand for ".once -w" or ".once --plain -w"
*/
static int dotCmdOutput(ShellState *p){
  int nArg = p->dot.nArg;        /* Number of arguments */
  char **azArg = p->dot.azArg;   /* Text of the arguments */
  char *zFile = 0;               /* The FILE argument */
  int i;                  /* Loop counter */
  int eMode = 0;          /* 0: .outout/.once, 'x'=.excel, 'w'=.www */
  int bOnce = 0;          /* 0: .output, 1: .once, 2: .excel/.www */
  int bPlain = 0;         /* --plain option */
  int bKeep = 0;          /* Keep redirecting */
  static const char *zBomUtf8 = "\357\273\277";
  const char *zBom = 0;
  char c = azArg[0][0];
  int n = strlen30(azArg[0]);

  failIfSafeMode(p, "cannot run .%s in safe mode", azArg[0]);
  if( c=='e' ){
    eMode = 'x';
    bOnce = 2;
  }else if( c=='w' ){
    eMode = 'w';
    bOnce = 2;
  }else if( n>=2 && cli_strncmp(azArg[0],"once",n)==0 ){
    bOnce = 1;
  }
  for(i=1; i<nArg; i++){
    char *z = azArg[i];
    if( z[0]=='-' ){
      if( z[1]=='-' ) z++;
      if( cli_strcmp(z,"-bom")==0 ){
        zBom = zBomUtf8;
      }else if( cli_strcmp(z,"-plain")==0 ){
        bPlain = 1;
      }else if( c=='o' && z[0]=='1' && z[1]!=0 && z[2]==0
             && (z[1]=='x' || z[1]=='e' || z[1]=='w') ){
        if( bKeep || eMode ){
          dotCmdError(p, i, "incompatible with prior options",0);
          goto dotCmdOutput_error;
        }
        eMode = z[1];
      }else if( cli_strcmp(z,"-show")==0 ){
        if( cli_output_capture ){
          sqlite3_fprintf(stdout, "%s", sqlite3_str_value(cli_output_capture));
        }
      }else if( cli_strcmp(z,"-keep")==0 ){
        bKeep = 1;
      }else if( optionMatch(z,"error-prefix") ){
        if( i+1>=nArg ){
          dotCmdError(p, i, "missing argument", 0);
          return 1;
        }
        free(p->zErrPrefix);
        i++;
        p->zErrPrefix = azArg[i][0]==0 ? 0 : strdup(azArg[i]);
      }else{
        dotCmdError(p, i, "unknown option", 0);
        sqlite3_free(zFile);
        return 1;
      }
    }else if( zFile==0 && eMode==0 ){
      if( bKeep ){
        dotCmdError(p, i, "incompatible with prior options",0);
        goto dotCmdOutput_error;
      }
      if( cli_strcmp(z, "memory")==0 && bOnce ){
        dotCmdError(p, 0, "cannot redirect to \"memory\"", 0);
        goto dotCmdOutput_error;
      }
      if( cli_strcmp(z, "off")==0 ){
#ifdef _WIN32
        zFile = sqlite3_mprintf("nul");
#else
        zFile = sqlite3_mprintf("/dev/null");
#endif
      }else{
        zFile = sqlite3_mprintf("%s", z);
      }
      if( zFile && zFile[0]=='|' ){
        while( i+1<nArg ) zFile = sqlite3_mprintf("%z %s", zFile, azArg[++i]);
        break;
      }
    }else{
      dotCmdError(p, i, "surplus argument", 0);
      sqlite3_free(zFile);
      return 1;
    }
  }
  if( zFile==0 && !bKeep ){
    zFile = sqlite3_mprintf("stdout");
    shell_check_oom(zFile);
  }
  if( bOnce ){
    p->nPopOutput = 2;
  }else{
    p->nPopOutput = 0;
  }
  if( !bKeep ) output_reset(p);
#ifndef SQLITE_NOHAVE_SYSTEM
  if( eMode=='e' || eMode=='x' || eMode=='w' ){
    p->doXdgOpen = 1;
    modePush(p);
    if( eMode=='x' ){
      /* spreadsheet mode.  Output as CSV. */
      newTempFile(p, "csv");
      p->mode.mFlags &= ~MFLG_ECHO;
      p->mode.eMode = MODE_Csv;
      modeSetStr(&p->mode.spec.zColumnSep, SEP_Comma);
      modeSetStr(&p->mode.spec.zRowSep, SEP_CrLf);
#ifdef _WIN32
      zBom = zBomUtf8;  /* Always include the BOM on Windows, as Excel does
                        ** not work without it. */
#endif
    }else if( eMode=='w' ){
      /* web-browser mode. */
      newTempFile(p, "html");
      if( !bPlain ) p->mode.eMode = MODE_Www;
    }else{
      /* text editor mode */
      newTempFile(p, "txt");
    }
    sqlite3_free(zFile);
    zFile = sqlite3_mprintf("%s", p->zTempFile);
  }
#endif /* SQLITE_NOHAVE_SYSTEM */
  if( !bKeep ) shell_check_oom(zFile);
  if( bKeep ){
    /* no-op */
  }else if( cli_strcmp(zFile,"memory")==0 ){
    if( cli_output_capture ){
      sqlite3_str_free(cli_output_capture);
    }
    cli_output_capture = sqlite3_str_new(0);
  }else if( zFile[0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
    eputz("Error: pipes are not supported in this OS\n");
    output_redir(p, stdout);
    goto dotCmdOutput_error;
#else
    FILE *pfPipe = sqlite3_popen(zFile + 1, "w");
    if( pfPipe==0 ){
      assert( stderr!=NULL );
      cli_printf(stderr,"Error: cannot open pipe \"%s\"\n", zFile + 1);
      goto dotCmdOutput_error;
    }else{
      output_redir(p, pfPipe);
      if( zBom ) cli_puts(zBom, pfPipe);
      sqlite3_snprintf(sizeof(p->outfile), p->outfile, "%s", zFile);
    }
#endif
  }else{
    FILE *pfFile = output_file_open(p, zFile);
    if( pfFile==0 ){
      if( cli_strcmp(zFile,"off")!=0 ){
       assert( stderr!=NULL );
       cli_printf(stderr,"Error: cannot write to \"%s\"\n", zFile);
      }
      goto dotCmdOutput_error;
    } else {
      output_redir(p, pfFile);
      if( zBom ) cli_puts(zBom, pfFile);
      if( bPlain && eMode=='w' ){
        cli_puts(
          "<!DOCTYPE html>\n<BODY>\n<PLAINTEXT>\n",
          pfFile
        );
      }
      sqlite3_snprintf(sizeof(p->outfile), p->outfile, "%s", zFile);
    }
  }
  sqlite3_free(zFile);
  return 0;

dotCmdOutput_error:
  sqlite3_free(zFile);
  return 1;
}

/*
** DOT-COMMAND: .check
** USAGE: .check [OPTIONS] PATTERN
**
** Verify results of commands since the most recent .testcase command.
** Restore output to the console, unless --keep is used.
**
** If PATTERN starts with "<<ENDMARK" then the actual pattern is taken from
** subsequent lines of text up to the first line that begins with ENDMARK.
** All pattern lines and the ENDMARK are discarded.
**
** Options:
**   --exact                Do an exact comparison including leading and
**                          trailing whitespace.
**   --glob                 Treat PATTERN as a GLOB
**   --keep                 Do not reset the testcase.  More .check commands
**                          will follow.
**   --notglob              Output should not match PATTERN
**   --show                 Write testcase output to the screen, for debugging.
*/
static int dotCmdCheck(ShellState *p){
  int nArg = p->dot.nArg;            /* Number of arguments */
  char **azArg = p->dot.azArg;       /* Text of the arguments */
  int i;                             /* Loop counter */
  int k;                             /* Result of pickStr() */
  char *zTest;                       /* Textcase result */
  int bKeep = 0;                     /* --keep option */
  char *zCheck = 0;                  /* PATTERN argument */
  char *zPattern = 0;                /* Actual test pattern */
  int eCheck = 0;                    /* 1: --glob,  2: --notglob,  3: --exact */
  int isOk;                          /* True if results are OK */
  sqlite3_int64 iStart = p->lineno;  /* Line number of .check statement */

  if( p->zTestcase[0]==0 ){
    dotCmdError(p, 0, "no .testcase is active", 0);
    return 1;
  }
  for(i=1; i<nArg; i++){
    char *z = azArg[i];
    if( z[0]=='-' && z[1]=='-' && z[2]!=0 ) z++;
    if( cli_strcmp(z,"-keep")==0 ){
      bKeep = 1;
    }else if( cli_strcmp(z,"-show")==0 ){
      if( cli_output_capture ){
        sqlite3_fprintf(stdout, "%s", sqlite3_str_value(cli_output_capture));
      }
      bKeep = 1;
    }else if( z[0]=='-'
          && (k = pickStr(&z[1],0,"glob","notglob","exact",""))>=0
    ){
      if( eCheck && eCheck!=k+1 ){
        dotCmdError(p, i, "incompatible with prior options",0);
        return 1;
      }
      eCheck = k+1;
    }else if( zCheck ){
      dotCmdError(p, i, "unknown option", 0);
      return 1;
    }else{
      zCheck = azArg[i];
    }
  }
  if( zCheck==0 ){
    dotCmdError(p, 0, "no PATTERN specified", 0);
    return 1;
  }
  if( cli_output_capture && sqlite3_str_length(cli_output_capture) ){
    zTest = sqlite3_str_value(cli_output_capture);
    shell_check_oom(zTest);
  }else{
    zTest = "";
  }
  p->nTestRun++;
  if( zCheck[0]=='<' && zCheck[1]=='<' && zCheck[2]!=0 ){
    int nCheck = strlen30(zCheck);
    sqlite3_str *pPattern = sqlite3_str_new(p->db);
    char zLine[2000];
    while( sqlite3_fgets(zLine,sizeof(zLine),p->in) ){
      if( strchr(zLine,'\n') ) p->lineno++;
      if( cli_strncmp(&zCheck[2],zLine,nCheck-2)==0 ) break;
      sqlite3_str_appendall(pPattern, zLine);
    }
    zPattern = sqlite3_str_finish(pPattern);
    if( zPattern==0 ){
      zPattern = sqlite3_mprintf("");
    }
  }else{
    zPattern = zCheck;
  }
  shell_check_oom(zPattern);
  switch( eCheck ){
    case 1: {
      char *zGlob = sqlite3_mprintf("*%s*", zPattern);
      isOk = testcase_glob(zGlob, zTest)!=0;
      sqlite3_free(zGlob);
      break;
    }
    case 2: {
      char *zGlob = sqlite3_mprintf("*%s*", zPattern);
      isOk = testcase_glob(zGlob, zTest)==0;
      sqlite3_free(zGlob);
      break;
    }
    case 3: {
      isOk = cli_strcmp(zTest,zPattern)==0;
      break;
    }
    default: {
      /* Skip leading and trailing \n and \r on both pattern and test output */
      const char *z1 = zPattern;
      const char *z2 = zTest;
      size_t n1, n2;
      while( z1[0]=='\n' || z1[0]=='\r' ) z1++;
      n1 = strlen(z1);
      while( n1>0 && (z1[n1-1]=='\n' || z1[n1-1]=='\r') ) n1--;
      while( z2[0]=='\n' || z2[0]=='\r' ) z2++;
      n2 = strlen(z2);
      while( n2>0 && (z2[n2-1]=='\n' || z2[n2-1]=='\r') ) n2--;
      isOk = n1==n2 && memcmp(z1,z2,n1)==0;
      break;
    }
  }
  if( !isOk ){
    sqlite3_fprintf(stderr,
          "%s:%lld: .check failed for testcase %s\n",
        p->zInFile, iStart, p->zTestcase);
    p->nTestErr++;
    sqlite3_fprintf(stderr, "Expected: [%s]\n", zPattern);
    sqlite3_fprintf(stderr, "Got:      [%s]\n", zTest);
  }
  if( zPattern!=zCheck ){
    sqlite3_free(zPattern);
  }
  if( !bKeep ){
    output_reset(p);
    p->zTestcase[0] = 0;
  }
  return 0;
}

/*
** DOT-COMMAND: .testcase
** USAGE: .testcase [OPTIONS] NAME
**
** Start a new test case identified by NAME.  All output
** through the next ".check" command is captured for comparison. See the
** ".check" commandn for additional informatioon.
**
** Options:
**   --error-prefix TEXT       Change error message prefix text to TEXT
*/
static int dotCmdTestcase(ShellState *p){
  int nArg = p->dot.nArg;        /* Number of arguments */
  char **azArg = p->dot.azArg;   /* Text of the arguments */
  int i;                         /* Loop counter */
  const char *zName = 0;         /* Testcase name */

  for(i=1; i<nArg; i++){
    char *z = azArg[i];
    if( z[0]=='-' && z[1]=='-' && z[2]!=0 ) z++;
    if( optionMatch(z,"error-prefix") ){
      if( i+1>=nArg ){
        dotCmdError(p, i, "missing argument", 0);
        return 1;
      }
      free(p->zErrPrefix);
      i++;
      p->zErrPrefix = azArg[i][0]==0 ? 0 : strdup(azArg[i]);
    }else if( zName ){
      dotCmdError(p, i, "unknown option", 0);
      return 1;
    }else{
      zName = azArg[i];
    }
  }
  output_reset(p);
  if( cli_output_capture ){
    sqlite3_str_free(cli_output_capture);
  }
  cli_output_capture = sqlite3_str_new(0);
  if( zName ){
    sqlite3_snprintf(sizeof(p->zTestcase), p->zTestcase, "%s", zName);
  }else{
    sqlite3_snprintf(sizeof(p->zTestcase), p->zTestcase, "%s:%lld",
                     p->zInFile, p->lineno);
  }
  return 0;
}

/*
** Enlarge the space allocated in p->dot so that it can hold more
** than nArg parsed command-line arguments.
*/
static void parseDotRealloc(ShellState *p, int nArg){
  p->dot.nAlloc = nArg+22;
  p->dot.azArg = realloc(p->dot.azArg,p->dot.nAlloc*sizeof(char*));
  shell_check_oom(p->dot.azArg);
  p->dot.aiOfst = realloc(p->dot.aiOfst,p->dot.nAlloc*sizeof(int));
  shell_check_oom(p->dot.aiOfst);
  p->dot.abQuot = realloc(p->dot.abQuot,p->dot.nAlloc);
  shell_check_oom(p->dot.abQuot);
}


/*
** Parse input line zLine up into individual arguments.  Retain the
** parse in the p->dot substructure.
*/
static void parseDotCmdArgs(const char *zLine, ShellState *p){
  char *z;
  int h = 1;
  int nArg = 0;
  size_t szLine;

  p->dot.zOrig = zLine;
  free(p->dot.zCopy);
  z = p->dot.zCopy = strdup(zLine);
  shell_check_oom(z);
  szLine = strlen(z);
  while( szLine>0 && IsSpace(z[szLine-1]) ) szLine--;
  if( szLine>0 && z[szLine-1]==';' ){
    szLine--;
    while( szLine>0 && IsSpace(z[szLine-1]) ) szLine--;
  }
  z[szLine] = 0;
  parseDotRealloc(p, 2);
  while( z[h] ){
    while( IsSpace(z[h]) ){ h++; }
    if( z[h]==0 ) break;
    if( nArg+2>p->dot.nAlloc ){
      parseDotRealloc(p, nArg);
    }
    if( z[h]=='\'' || z[h]=='"' ){
      int delim = z[h++];
      p->dot.abQuot[nArg] = 1;
      p->dot.azArg[nArg] = &z[h];
      p->dot.aiOfst[nArg] = h;
      while( z[h] && z[h]!=delim ){
        if( z[h]=='\\' && delim=='"' && z[h+1]!=0 ) h++;
        h++;
      }
      if( z[h]==delim ){
        z[h++] = 0;
      }
      if( delim=='"' ) resolve_backslashes(p->dot.azArg[nArg]);
    }else{
      p->dot.abQuot[nArg] = 0;
      p->dot.azArg[nArg] = &z[h];
      p->dot.aiOfst[nArg] = h;
      while( z[h] && !IsSpace(z[h]) ){ h++; }
      if( z[h] ) z[h++] = 0;
    }
    nArg++;
  }
  p->dot.nArg = nArg;
  p->dot.azArg[nArg] = 0;
}

/*
** If an input line begins with "." then invoke this routine to
** process that line.
**
** Return 1 on error, 2 to exit, and 0 otherwise.
*/
static int do_meta_command(const char *zLine, ShellState *p){
  int nArg;
  int n, c;
  int rc = 0;
  char **azArg;

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
  if( p->expert.pExpert ){
    expertFinish(p, 1, 0);
  }
#endif

  /* Parse the input line into tokens stored in p->dot.
  */
  parseDotCmdArgs(zLine, p);
  nArg = p->dot.nArg;
  azArg = p->dot.azArg;

  /* Process the input line.
  */
  if( nArg==0 ) return 0; /* no tokens, no error */
  n = strlen30(azArg[0]);
  c = azArg[0][0];
  clearTempFile(p);

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( c=='a' && cli_strncmp(azArg[0], "auth", n)==0 ){
    if( nArg!=2 ){
      cli_printf(stderr, "Usage: .auth ON|OFF\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    if( booleanValue(azArg[1]) ){
      sqlite3_set_authorizer(p->db, shellAuth, p);
    }else if( p->bSafeModePersist ){
      sqlite3_set_authorizer(p->db, safeModeAuth, p);
    }else{
      sqlite3_set_authorizer(p->db, 0, 0);
    }
  }else
#endif

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB) \
  && !defined(SQLITE_SHELL_FIDDLE)
  if( c=='a' && cli_strncmp(azArg[0], "archive", n)==0 ){
    open_db(p, 0);
    failIfSafeMode(p, "cannot run .archive in safe mode");
    rc = arDotCommand(p, 0, azArg, nArg);
  }else
#endif

#ifndef SQLITE_SHELL_FIDDLE
  if( (c=='b' && n>=3 && cli_strncmp(azArg[0], "backup", n)==0)
   || (c=='s' && n>=3 && cli_strncmp(azArg[0], "save", n)==0)
  ){
    const char *zDestFile = 0;
    const char *zDb = 0;
    sqlite3 *pDest;
    sqlite3_backup *pBackup;
    int j;
    int bAsync = 0;
    const char *zVfs = 0;
    failIfSafeMode(p, "cannot run .%s in safe mode", azArg[0]);
    for(j=1; j<nArg; j++){
      const char *z = azArg[j];
      if( z[0]=='-' ){
        if( z[1]=='-' ) z++;
        if( cli_strcmp(z, "-append")==0 ){
          zVfs = "apndvfs";
        }else
        if( cli_strcmp(z, "-async")==0 ){
          bAsync = 1;
        }else
        {
          dotCmdError(p, j, "unknown option", "should be -append or -async");
          return 1;
        }
      }else if( zDestFile==0 ){
        zDestFile = azArg[j];
      }else if( zDb==0 ){
        zDb = zDestFile;
        zDestFile = azArg[j];
      }else{
        cli_printf(stderr, "Usage: .backup ?DB? ?OPTIONS? FILENAME\n");
        return 1;
      }
    }
    if( zDestFile==0 ){
      cli_printf(stderr, "missing FILENAME argument on .backup\n");
      return 1;
    }
    if( zDb==0 ) zDb = "main";
    rc = sqlite3_open_v2(zDestFile, &pDest,
                  SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, zVfs);
    if( rc!=SQLITE_OK ){
      cli_printf(stderr,"Error: cannot open \"%s\"\n", zDestFile);
      close_db(pDest);
      return 1;
    }
    if( bAsync ){
      sqlite3_exec(pDest, "PRAGMA synchronous=OFF; PRAGMA journal_mode=OFF;",
                   0, 0, 0);
    }
    open_db(p, 0);
    pBackup = sqlite3_backup_init(pDest, "main", p->db, zDb);
    if( pBackup==0 ){
      shellDatabaseError(pDest);
      close_db(pDest);
      return 1;
    }
    while(  (rc = sqlite3_backup_step(pBackup,100))==SQLITE_OK ){}
    sqlite3_backup_finish(pBackup);
    if( rc==SQLITE_DONE ){
      rc = 0;
    }else{
      shellDatabaseError(pDest);
      rc = 1;
    }
    close_db(pDest);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "bail", n)==0 ){
    if( nArg==2 ){
      bail_on_error = booleanValue(azArg[1]);
    }else{
      eputz("Usage: .bail on|off\n");
      rc = 1;
    }
  }else

  /* Undocumented.  Legacy only.  See "crlf" below */
  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "binary", n)==0 ){
    eputz("The \".binary\" command is deprecated.\n");
    rc = 1;
  }else

  /* The undocumented ".breakpoint" command causes a call to the no-op
  ** routine named test_breakpoint().
  */
  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "breakpoint", n)==0 ){
    test_breakpoint();
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='c' && cli_strcmp(azArg[0],"cd")==0 ){
    failIfSafeMode(p, "cannot run .cd in safe mode");
    if( nArg==2 ){
#if defined(_WIN32) || defined(WIN32)
      wchar_t *z = sqlite3_win32_utf8_to_unicode(azArg[1]);
      rc = !SetCurrentDirectoryW(z);
      sqlite3_free(z);
#else
      rc = chdir(azArg[1]);
#endif
      if( rc ){
        cli_printf(stderr,"Cannot change to directory \"%s\"\n", azArg[1]);
        rc = 1;
      }
    }else{
      eputz("Usage: .cd DIRECTORY\n");
      rc = 1;
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='c' && n>=3 && cli_strncmp(azArg[0], "changes", n)==0 ){
    if( nArg==2 ){
      setOrClearFlag(p, SHFLG_CountChanges, azArg[1]);
    }else{
      eputz("Usage: .changes on|off\n");
      rc = 1;
    }
  }else

  /* Cancel output redirection, if it is currently set (by .testcase)
  ** Then read the content of the testcase-out.txt file and compare against
  ** azArg[1].  If there are differences, report an error and exit.
  */
  if( c=='c' && n>=3 && cli_strncmp(azArg[0], "check", n)==0 ){
    rc = dotCmdCheck(p);
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='c' && cli_strncmp(azArg[0], "clone", n)==0 ){
    failIfSafeMode(p, "cannot run .clone in safe mode");
    if( nArg==2 ){
      tryToClone(p, azArg[1]);
    }else{
      eputz("Usage: .clone FILENAME\n");
      rc = 1;
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='c' && cli_strncmp(azArg[0], "connection", n)==0 ){
    if( nArg==1 ){
      /* List available connections */
      int i;
      for(i=0; i<ArraySize(p->aAuxDb); i++){
        const char *zFile = p->aAuxDb[i].zDbFilename;
        if( p->aAuxDb[i].db==0 && p->pAuxDb!=&p->aAuxDb[i] ){
          zFile = "(not open)";
        }else if( zFile==0 ){
          zFile = "(memory)";
        }else if( zFile[0]==0 ){
          zFile = "(temporary-file)";
        }
        if( p->pAuxDb == &p->aAuxDb[i] ){
          cli_printf(stdout, "ACTIVE %d: %s\n", i, zFile);
        }else if( p->aAuxDb[i].db!=0 ){
          cli_printf(stdout, "       %d: %s\n", i, zFile);
        }
      }
    }else if( nArg==2 && IsDigit(azArg[1][0]) && azArg[1][1]==0 ){
      int i = azArg[1][0] - '0';
      if( p->pAuxDb != &p->aAuxDb[i] && i>=0 && i<ArraySize(p->aAuxDb) ){
        p->pAuxDb->db = p->db;
        p->pAuxDb = &p->aAuxDb[i];
        globalDb = p->db = p->pAuxDb->db;
        p->pAuxDb->db = 0;
      }
    }else if( nArg==3 && cli_strcmp(azArg[1], "close")==0
           && IsDigit(azArg[2][0]) && azArg[2][1]==0 ){
      int i = azArg[2][0] - '0';
      if( i<0 || i>=ArraySize(p->aAuxDb) ){
        /* No-op */
      }else if( p->pAuxDb == &p->aAuxDb[i] ){
        eputz("cannot close the active database connection\n");
        rc = 1;
      }else if( p->aAuxDb[i].db ){
        session_close_all(p, i);
        close_db(p->aAuxDb[i].db);
        p->aAuxDb[i].db = 0;
      }
    }else{
      eputz("Usage: .connection [close] [CONNECTION-NUMBER]\n");
      rc = 1;
    }
  }else

  if( c=='c' && n==4
   && (cli_strncmp(azArg[0], "crlf", n)==0
       || cli_strncmp(azArg[0], "crnl",n)==0)
  ){
    if( nArg==2 ){
#ifdef _WIN32
      if( booleanValue(azArg[1]) ){
        p->mode.mFlags |= MFLG_CRLF;
      }else{
        p->mode.mFlags &= ~MFLG_CRLF;
      }
#else
      p->mode.mFlags &= ~MFLG_CRLF;
#endif
    }
    cli_printf(stderr, "crlf is %s\n", 
       (p->mode.mFlags & MFLG_CRLF)!=0 ? "ON" : "OFF");
  }else

  if( c=='d' && n>1 && cli_strncmp(azArg[0], "databases", n)==0 ){
    char **azName = 0;
    int nName = 0;
    sqlite3_stmt *pStmt;
    int i;
    open_db(p, 0);
    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
    if( rc ){
      shellDatabaseError(p->db);
      rc = 1;
    }else{
      while( sqlite3_step(pStmt)==SQLITE_ROW ){
        const char *zSchema = (const char *)sqlite3_column_text(pStmt,1);
        const char *zFile = (const char*)sqlite3_column_text(pStmt,2);
        if( zSchema==0 || zFile==0 ) continue;
        azName = sqlite3_realloc64(azName, (nName+1)*2*sizeof(char*));
        shell_check_oom(azName);
        azName[nName*2] = strdup(zSchema);
        azName[nName*2+1] = strdup(zFile);
        nName++;
      }
    }
    sqlite3_finalize(pStmt);
    for(i=0; i<nName; i++){
      int eTxn = sqlite3_txn_state(p->db, azName[i*2]);
      int bRdonly = sqlite3_db_readonly(p->db, azName[i*2]);
      const char *z = azName[i*2+1];
      cli_printf(p->out, "%s: %s %s%s\n",
            azName[i*2], z && z[0] ? z : "\"\"", bRdonly ? "r/o" : "r/w",
            eTxn==SQLITE_TXN_NONE ? "" :
            eTxn==SQLITE_TXN_READ ? " read-txn" : " write-txn");
      free(azName[i*2]);
      free(azName[i*2+1]);
    }
    sqlite3_free(azName);
  }else

  if( c=='d' && n>=3 && cli_strncmp(azArg[0], "dbconfig", n)==0 ){
    static const struct DbConfigChoices {
      const char *zName;
      int op;
    } aDbConfig[] = {
        { "attach_create",      SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE  },
        { "attach_write",       SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE   },
        { "comments",           SQLITE_DBCONFIG_ENABLE_COMMENTS       },
        { "defensive",          SQLITE_DBCONFIG_DEFENSIVE             },
        { "dqs_ddl",            SQLITE_DBCONFIG_DQS_DDL               },
        { "dqs_dml",            SQLITE_DBCONFIG_DQS_DML               },
        { "enable_fkey",        SQLITE_DBCONFIG_ENABLE_FKEY           },
        { "enable_qpsg",        SQLITE_DBCONFIG_ENABLE_QPSG           },
        { "enable_trigger",     SQLITE_DBCONFIG_ENABLE_TRIGGER        },
        { "enable_view",        SQLITE_DBCONFIG_ENABLE_VIEW           },
        { "fts3_tokenizer",     SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER },
        { "fp_digits",          SQLITE_DBCONFIG_FP_DIGITS             },
        { "legacy_alter_table", SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    },
        { "legacy_file_format", SQLITE_DBCONFIG_LEGACY_FILE_FORMAT    },
        { "load_extension",     SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
        { "no_ckpt_on_close",   SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      },
        { "reset_database",     SQLITE_DBCONFIG_RESET_DATABASE        },
        { "reverse_scanorder",  SQLITE_DBCONFIG_REVERSE_SCANORDER     },
        { "stmt_scanstatus",    SQLITE_DBCONFIG_STMT_SCANSTATUS       },
        { "trigger_eqp",        SQLITE_DBCONFIG_TRIGGER_EQP           },
        { "trusted_schema",     SQLITE_DBCONFIG_TRUSTED_SCHEMA        },
        { "writable_schema",    SQLITE_DBCONFIG_WRITABLE_SCHEMA       },
    };
    int ii, v;
    open_db(p, 0);
    for(ii=0; ii<ArraySize(aDbConfig); ii++){
      if( nArg>1 && cli_strcmp(azArg[1], aDbConfig[ii].zName)!=0 ) continue;
      if( nArg>=3 ){
        if( aDbConfig[ii].op==SQLITE_DBCONFIG_FP_DIGITS ){
          sqlite3_db_config(p->db, aDbConfig[ii].op, atoi(azArg[2]), 0);
        }else{
          sqlite3_db_config(p->db, aDbConfig[ii].op, booleanValue(azArg[2]), 0);
        }
      }
      sqlite3_db_config(p->db, aDbConfig[ii].op, -1, &v);
      if( aDbConfig[ii].op==SQLITE_DBCONFIG_FP_DIGITS ){
        cli_printf(p->out, "%19s %d\n", aDbConfig[ii].zName, v);
      }else{
        cli_printf(p->out, "%19s %s\n",
                        aDbConfig[ii].zName, v ? "on" : "off");
      }
      if( nArg>1 ) break;
    }
    if( nArg>1 && ii==ArraySize(aDbConfig) ){
      dotCmdError(p, 1, "unknown dbconfig",
         "Enter \".dbconfig\" with no arguments for a list");
    }
  }else

#if SQLITE_SHELL_HAVE_RECOVER
  if( c=='d' && n>=3 && cli_strncmp(azArg[0], "dbinfo", n)==0 ){
    rc = shell_dbinfo_command(p, nArg, azArg);
  }else

  if( c=='r' && cli_strncmp(azArg[0], "recover", n)==0 ){
    open_db(p, 0);
    rc = recoverDatabaseCmd(p, nArg, azArg);
  }else
#endif /* SQLITE_SHELL_HAVE_RECOVER */

  if( c=='d' && cli_strncmp(azArg[0], "dump", n)==0 ){
    char *zLike = 0;
    char *zSql;
    int i;
    int savedShellFlags = p->shellFlgs;
    Mode saved_mode;
    ShellClearFlag(p,
       SHFLG_PreserveRowid|SHFLG_DumpDataOnly|SHFLG_DumpNoSys);
    for(i=1; i<nArg; i++){
      if( azArg[i][0]=='-' ){
        const char *z = azArg[i]+1;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"preserve-rowids")==0 ){
#ifdef SQLITE_OMIT_VIRTUALTABLE
          dotCmdError(p, i, "unable",
            "The --preserve-rowids option is not compatible"
                " with SQLITE_OMIT_VIRTUALTABLE");
          rc = 1;
          sqlite3_free(zLike);
          goto meta_command_exit;
#else
          ShellSetFlag(p, SHFLG_PreserveRowid);
#endif
        }else
        if( cli_strcmp(z,"newlines")==0 ){
          /*ShellSetFlag(p, SHFLG_Newlines);*/
        }else
        if( cli_strcmp(z,"data-only")==0 ){
          ShellSetFlag(p, SHFLG_DumpDataOnly);
        }else
        if( cli_strcmp(z,"nosys")==0 ){
          ShellSetFlag(p, SHFLG_DumpNoSys);
        }else
        {
          dotCmdError(p, i, "unknown option", 0);
          rc = 1;
          sqlite3_free(zLike);
          goto meta_command_exit;
        }
      }else{
        /* azArg[i] contains a LIKE pattern. This ".dump" request should
        ** only dump data for tables for which either the table name matches
        ** the LIKE pattern, or the table appears to be a shadow table of
        ** a virtual table for which the name matches the LIKE pattern.
        */
        char *zExpr = sqlite3_mprintf(
            "name LIKE %Q ESCAPE '\\' OR EXISTS ("
            "  SELECT 1 FROM sqlite_schema WHERE "
            "    name LIKE %Q ESCAPE '\\' AND"
            "    sql LIKE 'CREATE VIRTUAL TABLE%%' AND"
            "    substr(o.name, 1, length(name)+1) == (name||'_')"
            ")", azArg[i], azArg[i]
        );

        if( zLike ){
          zLike = sqlite3_mprintf("%z OR %z", zLike, zExpr);
        }else{
          zLike = zExpr;
        }
      }
    }

    open_db(p, 0);

    modeDup(&saved_mode, &p->mode);
    outputDumpWarning(p, zLike);
    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
      /* When playing back a "dump", the content might appear in an order
      ** which causes immediate foreign key constraints to be violated.
      ** So disable foreign-key constraint enforcement to prevent problems. */
      cli_puts("PRAGMA foreign_keys=OFF;\n", p->out);
      cli_puts("BEGIN TRANSACTION;\n", p->out);
    }
    p->writableSchema = 0;
    p->mode.spec.bTitles = QRF_No;
    /* Set writable_schema=ON since doing so forces SQLite to initialize
    ** as much of the schema as it can even if the sqlite_schema table is
    ** corrupt. */
    sqlite3_exec(p->db, "SAVEPOINT dump; PRAGMA writable_schema=ON", 0, 0, 0);
    p->nErr = 0;
    if( zLike==0 ) zLike = sqlite3_mprintf("true");
    zSql = sqlite3_mprintf(
      "SELECT name, type, sql FROM sqlite_schema AS o "
      "WHERE (%s) AND type=='table'"
      "  AND sql NOT NULL"
      " ORDER BY tbl_name='sqlite_sequence', rowid",
      zLike
    );
    run_schema_dump_query(p,zSql);
    sqlite3_free(zSql);
    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
      zSql = sqlite3_mprintf(
        "SELECT sql FROM sqlite_schema AS o "
        "WHERE (%s) AND sql NOT NULL"
        "  AND type IN ('index','trigger','view') "
        "ORDER BY type COLLATE NOCASE DESC",
        zLike
      );
      run_table_dump_query(p, zSql);
      sqlite3_free(zSql);
    }
    sqlite3_free(zLike);
    if( p->writableSchema ){
      cli_puts("PRAGMA writable_schema=OFF;\n", p->out);
      p->writableSchema = 0;
    }
    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
    sqlite3_exec(p->db, "RELEASE dump;", 0, 0, 0);
    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
      cli_puts(p->nErr?"ROLLBACK; -- due to errors\n":"COMMIT;\n", p->out);
    }
    p->shellFlgs = savedShellFlags;
    modeFree(&p->mode);
    p->mode = saved_mode;
    rc = p->nErr>0;
  }else

  if( c=='e' && cli_strncmp(azArg[0], "echo", n)==0 ){
    if( nArg==2 ){
      if( booleanValue(azArg[1]) ){
        p->mode.mFlags |= MFLG_ECHO;
      }else{
        p->mode.mFlags &= ~MFLG_ECHO;
      }
    }else{
      eputz("Usage: .echo on|off\n");
      rc = 1;
    }
  }else

  if( c=='d' && n>=3 && cli_strncmp(azArg[0], "dbtotxt", n)==0 ){
    open_db(p, 0);
    rc = shell_dbtotxt_command(p, nArg, azArg);
  }else

  if( c=='e' && cli_strncmp(azArg[0], "eqp", n)==0 ){
    if( nArg==2 ){
      if( p->mode.autoEQPtrace ){
        if( p->db ) sqlite3_exec(p->db, "PRAGMA vdbe_trace=OFF;", 0, 0, 0);
        p->mode.autoEQPtrace = 0;
      }
      if( cli_strcmp(azArg[1],"full")==0 ){
        p->mode.autoEQP = AUTOEQP_full;
      }else if( cli_strcmp(azArg[1],"trigger")==0 ){
        p->mode.autoEQP = AUTOEQP_trigger;
#ifdef SQLITE_DEBUG
      }else if( cli_strcmp(azArg[1],"trace")==0 ){
        p->mode.autoEQP = AUTOEQP_full;
        p->mode.autoEQPtrace = 1;
        open_db(p, 0);
        sqlite3_exec(p->db, "SELECT name FROM sqlite_schema LIMIT 1", 0, 0, 0);
        sqlite3_exec(p->db, "PRAGMA vdbe_trace=ON;", 0, 0, 0);
#endif
      }else{
        p->mode.autoEQP = (u8)booleanValue(azArg[1]);
      }
    }else{
      eputz("Usage: .eqp off|on|trace|trigger|full\n");
      rc = 1;
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='e' && cli_strncmp(azArg[0], "exit", n)==0 ){
    if( nArg>1 && (rc = (int)integerValue(azArg[1]))!=0 ) cli_exit(rc);
    rc = 2;
  }else
#endif

  /* The ".explain" command is automatic now.  It is largely pointless.  It
  ** retained purely for backwards compatibility */
  if( c=='e' && cli_strncmp(azArg[0], "explain", n)==0 ){
    if( nArg>=2 ){
      if( cli_strcmp(azArg[1],"auto")==0 ){
        p->mode.autoExplain = 1;
      }else{
        p->mode.autoExplain = booleanValue(azArg[1]);
      }
    }
  }else

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
  if( c=='e' && cli_strncmp(azArg[0], "expert", n)==0 ){
    if( p->bSafeMode ){
      cli_printf(stderr,
            "Cannot run experimental commands such as \"%s\" in safe mode\n",
            azArg[0]);
      rc = 1;
    }else{
      open_db(p, 0);
      expertDotCommand(p, azArg, nArg);
    }
  }else
#endif

  if( c=='f' && cli_strncmp(azArg[0], "filectrl", n)==0 ){
    static const struct {
       const char *zCtrlName;   /* Name of a test-control option */
       int ctrlCode;            /* Integer code for that option */
       const char *zUsage;      /* Usage notes */
    } aCtrl[] = {
      { "chunk_size",     SQLITE_FCNTL_CHUNK_SIZE,      "SIZE"           },
      { "data_version",   SQLITE_FCNTL_DATA_VERSION,    ""               },
      { "has_moved",      SQLITE_FCNTL_HAS_MOVED,       ""               },
      { "lock_timeout",   SQLITE_FCNTL_LOCK_TIMEOUT,    "MILLISEC"       },
      { "persist_wal",    SQLITE_FCNTL_PERSIST_WAL,     "[BOOLEAN]"      },
   /* { "pragma",         SQLITE_FCNTL_PRAGMA,          "NAME ARG"       },*/
      { "psow",       SQLITE_FCNTL_POWERSAFE_OVERWRITE, "[BOOLEAN]"      },
      { "reserve_bytes",  SQLITE_FCNTL_RESERVE_BYTES,   "[N]"            },
      { "size_limit",     SQLITE_FCNTL_SIZE_LIMIT,      "[LIMIT]"        },
      { "tempfilename",   SQLITE_FCNTL_TEMPFILENAME,    ""               },
   /* { "win32_av_retry", SQLITE_FCNTL_WIN32_AV_RETRY,  "COUNT DELAY"    },*/
    };
    int filectrl = -1;
    int iCtrl = -1;
    sqlite3_int64 iRes = 0;  /* Integer result to display if rc2==1 */
    int isOk = 0;            /* 0: usage  1: %lld  2: no-result */
    int n2, i;
    const char *zCmd = 0;
    const char *zSchema = 0;

    open_db(p, 0);
    zCmd = nArg>=2 ? azArg[1] : "help";

    if( zCmd[0]=='-'
     && (cli_strcmp(zCmd,"--schema")==0 || cli_strcmp(zCmd,"-schema")==0)
     && nArg>=4
    ){
      zSchema = azArg[2];
      for(i=3; i<nArg; i++) azArg[i-2] = azArg[i];
      nArg -= 2;
      zCmd = azArg[1];
    }

    /* The argument can optionally begin with "-" or "--" */
    if( zCmd[0]=='-' && zCmd[1] ){
      zCmd++;
      if( zCmd[0]=='-' && zCmd[1] ) zCmd++;
    }

    /* --help lists all file-controls */
    if( cli_strcmp(zCmd,"help")==0 ){
      cli_puts("Available file-controls:\n", p->out);
      for(i=0; i<ArraySize(aCtrl); i++){
        cli_printf(p->out,
               "  .filectrl %s %s\n", aCtrl[i].zCtrlName, aCtrl[i].zUsage);
      }
      rc = 1;
      goto meta_command_exit;
    }

    /* convert filectrl text option to value. allow any unique prefix
    ** of the option name, or a numerical value. */
    n2 = strlen30(zCmd);
    for(i=0; i<ArraySize(aCtrl); i++){
      if( cli_strncmp(zCmd, aCtrl[i].zCtrlName, n2)==0 ){
        if( filectrl<0 ){
          filectrl = aCtrl[i].ctrlCode;
          iCtrl = i;
        }else{
          cli_printf(stderr,"Error: ambiguous file-control: \"%s\"\n"
                "Use \".filectrl --help\" for help\n", zCmd);
          rc = 1;
          goto meta_command_exit;
        }
      }
    }
    if( filectrl<0 ){
      cli_printf(stderr,"Error: unknown file-control: %s\n"
            "Use \".filectrl --help\" for help\n", zCmd);
    }else{
      switch(filectrl){
        case SQLITE_FCNTL_SIZE_LIMIT: {
          if( nArg!=2 && nArg!=3 ) break;
          iRes = nArg==3 ? integerValue(azArg[2]) : -1;
          sqlite3_file_control(p->db, zSchema, SQLITE_FCNTL_SIZE_LIMIT, &iRes);
          isOk = 1;
          break;
        }
        case SQLITE_FCNTL_LOCK_TIMEOUT:
        case SQLITE_FCNTL_CHUNK_SIZE: {
          int x;
          if( nArg!=3 ) break;
          x = (int)integerValue(azArg[2]);
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          isOk = 2;
          break;
        }
        case SQLITE_FCNTL_PERSIST_WAL:
        case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
          int x;
          if( nArg!=2 && nArg!=3 ) break;
          x = nArg==3 ? booleanValue(azArg[2]) : -1;
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          iRes = x;
          isOk = 1;
          break;
        }
        case SQLITE_FCNTL_DATA_VERSION:
        case SQLITE_FCNTL_HAS_MOVED: {
          int x;
          if( nArg!=2 ) break;
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          iRes = x;
          isOk = 1;
          break;
        }
        case SQLITE_FCNTL_TEMPFILENAME: {
          char *z = 0;
          if( nArg!=2 ) break;
          sqlite3_file_control(p->db, zSchema, filectrl, &z);
          if( z ){
            cli_printf(p->out, "%s\n", z);
            sqlite3_free(z);
          }
          isOk = 2;
          break;
        }
        case SQLITE_FCNTL_RESERVE_BYTES: {
          int x;
          if( nArg>=3 ){
            x = atoi(azArg[2]);
            sqlite3_file_control(p->db, zSchema, filectrl, &x);
          }
          x = -1;
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          cli_printf(p->out, "%d\n", x);
          isOk = 2;
          break;
        }
      }
    }
    if( isOk==0 && iCtrl>=0 ){
      cli_printf(p->out, "Usage: .filectrl %s %s\n",
                      zCmd, aCtrl[iCtrl].zUsage);
      rc = 1;
    }else if( isOk==1 ){
      char zBuf[100];
      sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", iRes);
      cli_printf(p->out, "%s\n", zBuf);
    }
  }else

  if( c=='f' && cli_strncmp(azArg[0], "fullschema", n)==0 ){
    ShellState data;
    int doStats = 0;
    int hasStat[5];
    int flgs = 0;
    char *zSql;
    if( nArg==2 && optionMatch(azArg[1], "indent") ){
      nArg = 1;
    }
    if( nArg!=1 ){
      eputz("Usage: .fullschema ?--indent?\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    zSql = sqlite3_mprintf(
       "SELECT shell_format_schema(sql,%d) FROM"
       "  (SELECT sql sql, type type, tbl_name tbl_name, name name, rowid x"
       "     FROM sqlite_schema UNION ALL"
       "   SELECT sql, type, tbl_name, name, rowid FROM sqlite_temp_schema) "
       "WHERE type!='meta' AND sql NOTNULL"
       "  AND name NOT LIKE 'sqlite__%%' ESCAPE '_' "
       "ORDER BY x", flgs);
    memcpy(&data, p, sizeof(data));
    data.mode.spec.bTitles = QRF_No;
    data.mode.eMode = MODE_List;
    data.mode.spec.eText = QRF_TEXT_Plain;
    data.mode.spec.nCharLimit = 0;
    data.mode.spec.zRowSep = "\n";
    rc = shell_exec(&data,zSql,0);
    sqlite3_free(zSql);
    if( rc==SQLITE_OK ){
      sqlite3_stmt *pStmt;
      memset(hasStat, 0, sizeof(hasStat));
      rc = sqlite3_prepare_v2(p->db,
               "SELECT substr(name,12,1) FROM sqlite_schema"
               " WHERE name GLOB 'sqlite_stat[134]'",
               -1, &pStmt, 0);
      if( rc==SQLITE_OK ){
        while( sqlite3_step(pStmt)==SQLITE_ROW ){
          int k = sqlite3_column_int(pStmt,0);
          assert( k==1 || k==3 || k==4 );
          hasStat[k] = 1;
          doStats = 1;
        }
      }
      sqlite3_finalize(pStmt);
    }
    if( doStats==0 ){
      cli_puts("/* No STAT tables available */\n", p->out);
    }else{
      cli_puts("ANALYZE sqlite_schema;\n", p->out);
      data.mode.eMode = MODE_Insert;
      if( hasStat[1] ){
        data.mode.spec.zTableName = "sqlite_stat1";
        shell_exec(&data, "SELECT * FROM sqlite_stat1", 0);
      }
      if( hasStat[4] ){
        data.mode.spec.zTableName = "sqlite_stat4";
        shell_exec(&data, "SELECT * FROM sqlite_stat4", 0);
      }
      cli_puts("ANALYZE sqlite_schema;\n", p->out);
    }
  }else

  if( c=='h' && cli_strncmp(azArg[0], "headers", n)==0 ){
    if( nArg==2 ){
      p->mode.spec.bTitles = booleanValue(azArg[1]) ? QRF_Yes : QRF_No;
      p->mode.mFlags |= MFLG_HDR;
      p->mode.spec.eTitle = aModeInfo[p->mode.eMode].eHdr;
    }else{
      eputz("Usage: .headers on|off\n");
      rc = 1;
    }
  }else

  if( c=='h' && cli_strncmp(azArg[0], "help", n)==0 ){
    if( nArg>=2 ){
      n = showHelp(p->out, azArg[1]);
      if( n==0 ){
        cli_printf(p->out, "Nothing matches '%s'\n", azArg[1]);
      }
    }else{
      showHelp(p->out, 0);
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='i' && cli_strncmp(azArg[0], "import", n)==0 ){
    rc = dotCmdImport(p);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

#ifndef SQLITE_UNTESTABLE
  if( c=='i' && cli_strncmp(azArg[0], "imposter", n)==0 ){
    char *zSql;
    char *zCollist = 0;
    sqlite3_stmt *pStmt;
    int tnum = 0;
    int isWO = 0;  /* True if making an imposter of a WITHOUT ROWID table */
    int lenPK = 0; /* Length of the PRIMARY KEY string for isWO tables */
    int i;
    if( !(nArg==3 || (nArg==2 && sqlite3_stricmp(azArg[1],"off")==0)) ){
      eputz("Usage: .imposter INDEX IMPOSTER\n"
            "       .imposter off\n");
      /* Also allowed, but not documented:
      **
      **    .imposter TABLE IMPOSTER
      **
      ** where TABLE is a WITHOUT ROWID table.  In that case, the
      ** imposter is another WITHOUT ROWID table with the columns in
      ** storage order. */
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    if( nArg==2 ){
      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 0, 1);
      goto meta_command_exit;
    }
    zSql = sqlite3_mprintf(
      "SELECT rootpage, 0 FROM sqlite_schema"
      " WHERE type='index' AND lower(name)=lower('%q')"
      "UNION ALL "
      "SELECT rootpage, 1 FROM sqlite_schema"
      " WHERE type='table' AND lower(name)=lower('%q')"
      "   AND sql LIKE '%%without%%rowid%%'",
      azArg[1], azArg[1]
    );
    sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      tnum = sqlite3_column_int(pStmt, 0);
      isWO = sqlite3_column_int(pStmt, 1);
    }
    sqlite3_finalize(pStmt);
    zSql = sqlite3_mprintf("PRAGMA index_xinfo='%q'", azArg[1]);
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    i = 0;
    while( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
      char zLabel[20];
      const char *zCol = (const char*)sqlite3_column_text(pStmt,2);
      i++;
      if( zCol==0 ){
        if( sqlite3_column_int(pStmt,1)==-1 ){
          zCol = "_ROWID_";
        }else{
          sqlite3_snprintf(sizeof(zLabel),zLabel,"expr%d",i);
          zCol = zLabel;
        }
      }
      if( isWO && lenPK==0 && sqlite3_column_int(pStmt,5)==0 && zCollist ){
        lenPK = (int)strlen(zCollist);
      }
      if( zCollist==0 ){
        zCollist = sqlite3_mprintf("\"%w\"", zCol);
      }else{
        zCollist = sqlite3_mprintf("%z,\"%w\"", zCollist, zCol);
      }
    }
    sqlite3_finalize(pStmt);
    if( i==0 || tnum==0 ){
      cli_printf(stderr,"no such index: \"%s\"\n", azArg[1]);
      rc = 1;
      sqlite3_free(zCollist);
      goto meta_command_exit;
    }
    if( lenPK==0 ) lenPK = 100000;
    zSql = sqlite3_mprintf(
          "CREATE TABLE \"%w\"(%s,PRIMARY KEY(%.*s))WITHOUT ROWID",
          azArg[2], zCollist, lenPK, zCollist);
    sqlite3_free(zCollist);
    rc = sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 2, tnum);
    if( rc==SQLITE_OK ){
      rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 0, 0);
      if( rc ){
        cli_printf(stderr,
              "Error in [%s]: %s\n", zSql, sqlite3_errmsg(p->db));
      }else{
        cli_printf(stdout, "%s;\n", zSql);
      }
    }else{
      cli_printf(stderr,"SQLITE_TESTCTRL_IMPOSTER returns %d\n", rc);
      rc = 1;
    }
    sqlite3_free(zSql);
  }else
#endif /* !defined(SQLITE_OMIT_TEST_CONTROL) */

  if( c=='i' && (cli_strncmp(azArg[0], "indices", n)==0
                 || cli_strncmp(azArg[0], "indexes", n)==0)
  ){
    sqlite3_str *pSql;
    int i;
    int allFlag = 0;
    int sysFlag = 0;
    int exprFlag = 0;
    int debugFlag = 0;  /* Undocument --debug flag */
    const char *zPattern = 0;
    const char *zSep = "WHERE";

    for(i=1; i<nArg; i++){
      if( azArg[i][0]=='-' ){
        const char *z = azArg[i]+1;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"all")==0 || cli_strcmp(z,"a")==0 ){
          allFlag = 1;
        }else
        if( cli_strcmp(z,"sys")==0 ){
          sysFlag = 1;
          allFlag = 0;
        }else
        if( cli_strcmp(z,"expr")==0 ){
          exprFlag = 1;
          allFlag = 0;
        }else
        if( cli_strcmp(z,"debug")==0 ){
          debugFlag = 1;
        }else
        {
          dotCmdError(p, i, "unknown option", 0);
          rc = 1;
          goto meta_command_exit;
        }
      }else if( zPattern==0 ){
        zPattern = azArg[i];
      }else{
        dotCmdError(p, i, "unknown argument", 0);
        rc = 1;
        goto meta_command_exit;
      }
    }

    open_db(p, 0);
    pSql = sqlite3_str_new(p->db);
    sqlite3_str_appendf(pSql,
      "SELECT if(t.schema='main',i.name,t.schema||'.'||i.name)\n"
      "FROM pragma_table_list t, pragma_index_list(t.name,t.schema) i\n"
    );
    if( exprFlag ){
      allFlag = 0;
      sqlite3_str_appendf(pSql,
        "%s (EXISTS(SELECT 1 FROM pragma_index_xinfo(i.name) WHERE cid=-2)\n"
        "       OR\n"
        "       EXISTS(SELECT cid FROM pragma_table_xinfo(t.name) WHERE hidden=2"
        " INTERSECT "
        " SELECT cid FROM pragma_index_info(i.name)))\n", zSep);
      zSep = "AND";
    }
    if( sysFlag ){
      sqlite3_str_appendf(pSql,
           "%s i.name LIKE 'sqlite__autoindex__%%' ESCAPE '_'\n", zSep);
      zSep = "AND";
    }else if( !allFlag ){
      sqlite3_str_appendf(pSql,
           "%s i.name NOT LIKE 'sqlite__%%' ESCAPE '_'\n", zSep);
      zSep = "AND";
    }
    if( zPattern ){
      sqlite3_str_appendf(pSql, "%s i.name LIKE '%%%q%%'\n", zSep, zPattern);
    }
    sqlite3_str_appendf(pSql, "ORDER BY 1");

    /* Run the SQL statement in "split" mode. */
    if( debugFlag ){
      cli_printf(stdout,"%s;\n", sqlite3_str_value(pSql));
    }else{
      modePush(p);
      modeChange(p, MODE_Split);
      shell_exec(p, sqlite3_str_value(pSql), 0);
      modePop(p);
    }
    sqlite3_str_free(pSql);
  }else

  if( c=='i' && cli_strncmp(azArg[0], "intck", n)==0 ){
    i64 iArg = 0;
    if( nArg==2 ){
      iArg = integerValue(azArg[1]);
      if( iArg==0 ) iArg = -1;
    }
    if( (nArg!=1 && nArg!=2) || iArg<0 ){
      cli_printf(stderr,"%s","Usage: .intck STEPS_PER_UNLOCK\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    rc = intckDatabaseCmd(p, iArg);
  }else

#ifdef SQLITE_ENABLE_IOTRACE
  if( c=='i' && cli_strncmp(azArg[0], "iotrace", n)==0 ){
    SQLITE_API extern void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...);
    if( iotrace && iotrace!=stdout ) fclose(iotrace);
    iotrace = 0;
    if( nArg<2 ){
      sqlite3IoTrace = 0;
    }else if( cli_strcmp(azArg[1], "-")==0 ){
      sqlite3IoTrace = iotracePrintf;
      iotrace = stdout;
    }else{
      iotrace = sqlite3_fopen(azArg[1], "w");
      if( iotrace==0 ){
        cli_printf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
        sqlite3IoTrace = 0;
        rc = 1;
      }else{
        sqlite3IoTrace = iotracePrintf;
      }
    }
  }else
#endif

  if( c=='l' && n>=5 && cli_strncmp(azArg[0], "limits", n)==0 ){
    static const struct {
       const char *zLimitName;   /* Name of a limit */
       int limitCode;            /* Integer code for that limit */
    } aLimit[] = {
      { "length",                SQLITE_LIMIT_LENGTH                    },
      { "sql_length",            SQLITE_LIMIT_SQL_LENGTH                },
      { "column",                SQLITE_LIMIT_COLUMN                    },
      { "expr_depth",            SQLITE_LIMIT_EXPR_DEPTH                },
      { "parser_depth",          SQLITE_LIMIT_PARSER_DEPTH              },
      { "compound_select",       SQLITE_LIMIT_COMPOUND_SELECT           },
      { "vdbe_op",               SQLITE_LIMIT_VDBE_OP                   },
      { "function_arg",          SQLITE_LIMIT_FUNCTION_ARG              },
      { "attached",              SQLITE_LIMIT_ATTACHED                  },
      { "like_pattern_length",   SQLITE_LIMIT_LIKE_PATTERN_LENGTH       },
      { "variable_number",       SQLITE_LIMIT_VARIABLE_NUMBER           },
      { "trigger_depth",         SQLITE_LIMIT_TRIGGER_DEPTH             },
      { "worker_threads",        SQLITE_LIMIT_WORKER_THREADS            },
    };
    int i, n2;
    open_db(p, 0);
    if( nArg==1 ){
      for(i=0; i<ArraySize(aLimit); i++){
        cli_printf(stdout, "%20s %d\n", aLimit[i].zLimitName,
              sqlite3_limit(p->db, aLimit[i].limitCode, -1));
      }
    }else if( nArg>3 ){
      eputz("Usage: .limit NAME ?NEW-VALUE?\n");
      rc = 1;
      goto meta_command_exit;
    }else{
      int iLimit = -1;
      n2 = strlen30(azArg[1]);
      for(i=0; i<ArraySize(aLimit); i++){
        if( sqlite3_strnicmp(aLimit[i].zLimitName, azArg[1], n2)==0 ){
          if( iLimit<0 ){
            iLimit = i;
          }else{
            cli_printf(stderr,"ambiguous limit: \"%s\"\n", azArg[1]);
            rc = 1;
            goto meta_command_exit;
          }
        }
      }
      if( iLimit<0 ){
        cli_printf(stderr,"unknown limit: \"%s\"\n"
              "enter \".limits\" with no arguments for a list.\n",
              azArg[1]);
        rc = 1;
        goto meta_command_exit;
      }
      if( nArg==3 ){
        sqlite3_limit(p->db, aLimit[iLimit].limitCode,
                      (int)integerValue(azArg[2]));
      }else{
        cli_printf(stdout, "%20s %d\n", aLimit[iLimit].zLimitName,
              sqlite3_limit(p->db, aLimit[iLimit].limitCode, -1));
      }
    }
  }else

  if( c=='l' && n>2 && cli_strncmp(azArg[0], "lint", n)==0 ){
    open_db(p, 0);
    lintDotCommand(p, azArg, nArg);
  }else

#if !defined(SQLITE_OMIT_LOAD_EXTENSION) && !defined(SQLITE_SHELL_FIDDLE)
  if( c=='l' && cli_strncmp(azArg[0], "load", n)==0 ){
    const char *zFile, *zProc;
    char *zErrMsg = 0;
    failIfSafeMode(p, "cannot run .load in safe mode");
    if( nArg<2 || azArg[1][0]==0 ){
      /* Must have a non-empty FILE. (Will not load self.) */
      eputz("Usage: .load FILE ?ENTRYPOINT?\n");
      rc = 1;
      goto meta_command_exit;
    }
    zFile = azArg[1];
    zProc = nArg>=3 ? azArg[2] : 0;
    open_db(p, 0);
    rc = sqlite3_load_extension(p->db, zFile, zProc, &zErrMsg);
    if( rc!=SQLITE_OK ){
      shellEmitError(zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }
  }else
#endif

  if( c=='l' && cli_strncmp(azArg[0], "log", n)==0 ){
    if( nArg!=2 ){
      eputz("Usage: .log FILENAME\n");
      rc = 1;
    }else{
      const char *zFile = azArg[1];
      if( p->bSafeMode
       && cli_strcmp(zFile,"on")!=0
       && cli_strcmp(zFile,"off")!=0
      ){
        sputz(stdout, "cannot set .log to anything other"
              " than \"on\" or \"off\"\n");
        zFile = "off";
      }
      output_file_close(p->pLog);
      if( cli_strcmp(zFile,"on")==0 ) zFile = "stdout";
      p->pLog = output_file_open(p, zFile);
    }
  }else

  if( c=='m' && cli_strncmp(azArg[0], "mode", n)==0 ){
    rc = dotCmdMode(p);
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='n' && cli_strcmp(azArg[0], "nonce")==0 ){
    if( nArg!=2 ){
      eputz("Usage: .nonce NONCE\n");
      rc = 1;
    }else if( p->zNonce==0 || cli_strcmp(azArg[1],p->zNonce)!=0 ){
      cli_printf(stderr,"line %lld: incorrect nonce: \"%s\"\n",
            p->lineno, azArg[1]);
      cli_exit(1);
    }else{
      p->bSafeMode = 0;
      return 0;  /* Return immediately to bypass the safe mode reset
                 ** at the end of this procedure */
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='n' && cli_strncmp(azArg[0], "nullvalue", n)==0 ){
    if( nArg==2 ){
      modeSetStr(&p->mode.spec.zNull, azArg[1]);
    }else{
      eputz("Usage: .nullvalue STRING\n");
      rc = 1;
    }
  }else

  if( c=='o' && cli_strncmp(azArg[0], "open", n)==0 && n>=2 ){
    const char *zFN = 0;     /* Pointer to constant filename */
    char *zNewFilename = 0;  /* Name of the database file to open */
    int iName = 1;           /* Index in azArg[] of the filename */
    int newFlag = 0;         /* True to delete file before opening */
    int openMode = SHELL_OPEN_UNSPEC;
    int openFlags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;

    if( p->bSafeMode ) openFlags = SQLITE_OPEN_READONLY;

    /* Check for command-line arguments */
    for(iName=1; iName<nArg; iName++){
      const char *z = azArg[iName];
#ifndef SQLITE_SHELL_FIDDLE
      if( optionMatch(z,"new") ){
        newFlag = 1;
#ifdef SQLITE_HAVE_ZLIB
      }else if( optionMatch(z, "zip") && !p->bSafeMode ){
        openMode = SHELL_OPEN_ZIPFILE;
#endif
      }else if( optionMatch(z, "append") && !p->bSafeMode ){
        openMode = SHELL_OPEN_APPENDVFS;
      }else if( optionMatch(z, "readonly") ){
        openFlags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
        openFlags |= SQLITE_OPEN_READONLY;
      }else if( optionMatch(z, "exclusive") ){
        openFlags |= SQLITE_OPEN_EXCLUSIVE;
      }else if( optionMatch(z, "ifexists") ){
        openFlags &= ~(SQLITE_OPEN_CREATE);
      }else if( optionMatch(z, "nofollow") ){
        openFlags |= SQLITE_OPEN_NOFOLLOW;
#ifndef SQLITE_OMIT_DESERIALIZE
      }else if( optionMatch(z, "deserialize") ){
        openMode = SHELL_OPEN_DESERIALIZE;
      }else if( optionMatch(z, "hexdb") ){
        openMode = SHELL_OPEN_HEXDB;
      }else if( optionMatch(z, "normal") ){
        openMode = SHELL_OPEN_NORMAL;
      }else if( optionMatch(z, "maxsize") && iName+1<nArg ){
        p->szMax = integerValue(azArg[++iName]);
#endif /* SQLITE_OMIT_DESERIALIZE */
      }else
#endif /* !SQLITE_SHELL_FIDDLE */
      if( z[0]=='-' ){
        cli_printf(stderr,"unknown option: %s\n", z);
        rc = 1;
        goto meta_command_exit;
      }else if( zFN ){
        cli_printf(stderr,"extra argument: \"%s\"\n", z);
        rc = 1;
        goto meta_command_exit;
      }else{
        zFN = z;
      }
    }

    /* Close the existing database */
    session_close_all(p, -1);
    close_db(p->db);
    p->db = 0;
    p->pAuxDb->zDbFilename = 0;
    sqlite3_free(p->pAuxDb->zFreeOnClose);
    p->pAuxDb->zFreeOnClose = 0;
    p->openMode = openMode;
    p->openFlags = openFlags;
    p->szMax = 0;

    /* If a filename is specified, try to open it first */
    if( zFN || p->openMode==SHELL_OPEN_HEXDB ){
      if( newFlag && zFN && !p->bSafeMode ){
        if( cli_strncmp(zFN,"file:",5)==0 ){
          char *zDel = shellFilenameFromUri(zFN);
          shell_check_oom(zDel);
          shellDeleteFile(zDel);
          sqlite3_free(zDel);
        }else{
          shellDeleteFile(zFN);
        }
      }
#ifndef SQLITE_SHELL_FIDDLE
      if( p->bSafeMode
       && p->openMode!=SHELL_OPEN_HEXDB
       && zFN
       && cli_strcmp(zFN,":memory:")!=0
      ){
        failIfSafeMode(p, "cannot open disk-based database files in safe mode");
      }
#else
      /* WASM mode has its own sandboxed pseudo-filesystem. */
#endif
      if( zFN ){
        zNewFilename = sqlite3_mprintf("%s", zFN);
        shell_check_oom(zNewFilename);
      }else{
        zNewFilename = 0;
      }
      p->pAuxDb->zDbFilename = zNewFilename;
      open_db(p, OPEN_DB_KEEPALIVE);
      if( p->db==0 ){
        cli_printf(stderr,"Error: cannot open '%s'\n", zNewFilename);
        sqlite3_free(zNewFilename);
      }else{
        p->pAuxDb->zFreeOnClose = zNewFilename;
      }
    }
    if( p->db==0 ){
      /* As a fall-back open a TEMP database */
      p->pAuxDb->zDbFilename = 0;
      open_db(p, 0);
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( (c=='o'
        && (cli_strncmp(azArg[0], "output", n)==0
            || cli_strncmp(azArg[0], "once", n)==0))
   || (c=='e' && n==5 && cli_strcmp(azArg[0],"excel")==0)
   || (c=='w' && n==3 && cli_strcmp(azArg[0],"www")==0)
  ){
    rc = dotCmdOutput(p);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='p' && n>=3 && cli_strncmp(azArg[0], "parameter", n)==0 ){
    open_db(p,0);
    if( nArg<=1 ) goto parameter_syntax_error;

    /* .parameter clear
    ** Clear all bind parameters by dropping the TEMP table that holds them.
    */
    if( nArg==2 && cli_strcmp(azArg[1],"clear")==0 ){
      sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp.sqlite_parameters;",
                   0, 0, 0);
    }else

    /* .parameter list
    ** List all bind parameters.
    */
    if( nArg==2 && cli_strcmp(azArg[1],"list")==0 ){
      sqlite3_stmt *pStmt = 0;
      int rx;
      int len = 0;
      rx = sqlite3_prepare_v2(p->db,
             "SELECT max(length(key)) "
             "FROM temp.sqlite_parameters;", -1, &pStmt, 0);
      if( rx==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
        len = sqlite3_column_int(pStmt, 0);
        if( len>40 ) len = 40;
      }
      sqlite3_finalize(pStmt);
      pStmt = 0;
      if( len ){
        rx = sqlite3_prepare_v2(p->db,
             "SELECT key, quote(value) "
             "FROM temp.sqlite_parameters;", -1, &pStmt, 0);
        while( rx==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
          cli_printf(p->out,
                "%-*s %s\n", len, sqlite3_column_text(pStmt,0),
                sqlite3_column_text(pStmt,1));
        }
        sqlite3_finalize(pStmt);
      }
    }else

    /* .parameter init
    ** Make sure the TEMP table used to hold bind parameters exists.
    ** Create it if necessary.
    */
    if( nArg==2 && cli_strcmp(azArg[1],"init")==0 ){
      bind_table_init(p);
    }else

    /* .parameter set NAME VALUE
    ** Set or reset a bind parameter.  NAME should be the full parameter
    ** name exactly as it appears in the query.  (ex: $abc, @def).  The
    ** VALUE can be in either SQL literal notation, or if not it will be
    ** understood to be a text string.
    */
    if( nArg==4 && cli_strcmp(azArg[1],"set")==0 ){
      int rx;
      char *zSql;
      sqlite3_stmt *pStmt;
      const char *zKey = azArg[2];
      const char *zValue = azArg[3];
      bind_table_init(p);
      zSql = sqlite3_mprintf(
                  "REPLACE INTO temp.sqlite_parameters(key,value)"
                  "VALUES(%Q,%s);", zKey, zValue);
      shell_check_oom(zSql);
      pStmt = 0;
      rx = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
      sqlite3_free(zSql);
      if( rx!=SQLITE_OK ){
        sqlite3_finalize(pStmt);
        pStmt = 0;
        zSql = sqlite3_mprintf(
                   "REPLACE INTO temp.sqlite_parameters(key,value)"
                   "VALUES(%Q,%Q);", zKey, zValue);
        shell_check_oom(zSql);
        rx = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
        sqlite3_free(zSql);
        if( rx!=SQLITE_OK ){
          cli_printf(p->out, "Error: %s\n", sqlite3_errmsg(p->db));
          sqlite3_finalize(pStmt);
          pStmt = 0;
          rc = 1;
        }
      }
      bind_prepared_stmt(p, pStmt);
      sqlite3_step(pStmt);
      sqlite3_finalize(pStmt);
    }else

    /* .parameter unset NAME
    ** Remove the NAME binding from the parameter binding table, if it
    ** exists.
    */
    if( nArg==3 && cli_strcmp(azArg[1],"unset")==0 ){
      char *zSql = sqlite3_mprintf(
          "DELETE FROM temp.sqlite_parameters WHERE key=%Q", azArg[2]);
      shell_check_oom(zSql);
      sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_free(zSql);
    }else
    /* If no command name matches, show a syntax error */
    parameter_syntax_error:
    showHelp(p->out, "parameter");
  }else

  if( c=='p' && n>=3 && cli_strncmp(azArg[0], "print", n)==0 ){
    int i;
    for(i=1; i<nArg; i++){
      if( i>1 ) cli_puts(" ", p->out);
      cli_puts(azArg[i], p->out);
    }
    cli_puts("\n", p->out);
  }else

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  if( c=='p' && n>=3 && cli_strncmp(azArg[0], "progress", n)==0 ){
    int i;
    int nn = 0;
    p->flgProgress = 0;
    p->mxProgress = 0;
    p->nProgress = 0;
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' ){
        z++;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"quiet")==0 || cli_strcmp(z,"q")==0 ){
          p->flgProgress |= SHELL_PROGRESS_QUIET;
          continue;
        }
        if( cli_strcmp(z,"reset")==0 ){
          p->flgProgress |= SHELL_PROGRESS_RESET;
          continue;
        }
        if( cli_strcmp(z,"once")==0 ){
          p->flgProgress |= SHELL_PROGRESS_ONCE;
          continue;
        }
        if( cli_strcmp(z,"timeout")==0 ){
          if( i==nArg-1 ){
            dotCmdError(p, i, "missing argument", 0);
            return 1;
          }
          i++;
          p->tmProgress = atof(azArg[i]);
          if( p->tmProgress>0.0 ){
            p->flgProgress = SHELL_PROGRESS_QUIET|SHELL_PROGRESS_TMOUT;
            if( nn==0 ) nn = 100;
          }
          continue;
        }
        if( cli_strcmp(z,"limit")==0 ){
          if( i+1>=nArg ){
            eputz("Error: missing argument on --limit\n");
            rc = 1;
            goto meta_command_exit;
          }else{
            p->mxProgress = (int)integerValue(azArg[++i]);
          }
          continue;
        }
        cli_printf(stderr,"Error: unknown option: \"%s\"\n", azArg[i]);
        rc = 1;
        goto meta_command_exit;
      }else{
        nn = (int)integerValue(z);
      }
    }
    open_db(p, 0);
    sqlite3_progress_handler(p->db, nn, progress_handler, p);
  }else
#endif /* SQLITE_OMIT_PROGRESS_CALLBACK */

  if( c=='p' && cli_strncmp(azArg[0], "prompt", n)==0 ){
    if( nArg >= 2) {
      shell_strncpy(mainPrompt,azArg[1],(int)ArraySize(mainPrompt)-1);
    }
    if( nArg >= 3) {
      shell_strncpy(continuePrompt,azArg[2],(int)ArraySize(continuePrompt)-1);
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='q' && cli_strncmp(azArg[0], "quit", n)==0 ){
    rc = 2;
  }else
#endif

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='r' && n>=3 && cli_strncmp(azArg[0], "read", n)==0 ){
    FILE *inSaved = p->in;
    i64 savedLineno = p->lineno;
    failIfSafeMode(p, "cannot run .read in safe mode");
    if( nArg!=2 ){
      eputz("Usage: .read FILE\n");
      rc = 1;
      goto meta_command_exit;
    }
    if( azArg[1][0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
      eputz("Error: pipes are not supported in this OS\n");
      rc = 1;
#else
      p->in = sqlite3_popen(azArg[1]+1, "r");
      if( p->in==0 ){
        cli_printf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
        rc = 1;
      }else{
        rc = process_input(p, "<pipe>");
        pclose(p->in);
      }
#endif
    }else if( (p->in = openChrSource(azArg[1]))==0 ){
      cli_printf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
      rc = 1;
    }else{
      char *zFilename = strdup(azArg[1]);
      rc = process_input(p, zFilename);
      free(zFilename);
      fclose(p->in);
    }
    p->in = inSaved;
    p->lineno = savedLineno;
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='r' && n>=3 && cli_strncmp(azArg[0], "restore", n)==0 ){
    const char *zSrcFile;
    const char *zDb;
    sqlite3 *pSrc;
    sqlite3_backup *pBackup;
    int nTimeout = 0;

    failIfSafeMode(p, "cannot run .restore in safe mode");
    if( nArg==2 ){
      zSrcFile = azArg[1];
      zDb = "main";
    }else if( nArg==3 ){
      zSrcFile = azArg[2];
      zDb = azArg[1];
    }else{
      eputz("Usage: .restore ?DB? FILE\n");
      rc = 1;
      goto meta_command_exit;
    }
    rc = sqlite3_open(zSrcFile, &pSrc);
    if( rc!=SQLITE_OK ){
      cli_printf(stderr,"Error: cannot open \"%s\"\n", zSrcFile);
      close_db(pSrc);
      return 1;
    }
    open_db(p, 0);
    pBackup = sqlite3_backup_init(p->db, zDb, pSrc, "main");
    if( pBackup==0 ){
      shellDatabaseError(p->db);
      close_db(pSrc);
      return 1;
    }
    while( (rc = sqlite3_backup_step(pBackup,100))==SQLITE_OK
          || rc==SQLITE_BUSY  ){
      if( rc==SQLITE_BUSY ){
        if( nTimeout++ >= 3 ) break;
        sqlite3_sleep(100);
      }
    }
    sqlite3_backup_finish(pBackup);
    if( rc==SQLITE_DONE ){
      rc = 0;
    }else if( rc==SQLITE_BUSY || rc==SQLITE_LOCKED ){
      eputz("Error: source database is busy\n");
      rc = 1;
    }else{
      shellDatabaseError(p->db);
      rc = 1;
    }
    close_db(pSrc);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='s' &&
     (cli_strncmp(azArg[0], "scanstats",  n)==0 ||
      cli_strncmp(azArg[0], "scanstatus", n)==0)
  ){
    if( nArg==2 ){
      if( cli_strcmp(azArg[1], "vm")==0 ){
        p->mode.scanstatsOn = 3;
      }else
      if( cli_strcmp(azArg[1], "est")==0 ){
        p->mode.scanstatsOn = 2;
      }else{
        p->mode.scanstatsOn = (u8)booleanValue(azArg[1]);
      }
      open_db(p, 0);
      sqlite3_db_config(
          p->db, SQLITE_DBCONFIG_STMT_SCANSTATUS, p->mode.scanstatsOn, (int*)0
      );
#if !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
      eputz("Warning: .scanstats not available in this build.\n");
#elif !defined(SQLITE_ENABLE_BYTECODE_VTAB)
      if( p->mode.scanstatsOn==3 ){
        eputz("Warning: \".scanstats vm\" not available in this build.\n");
      }
#endif
    }else{
      eputz("Usage: .scanstats on|off|est\n");
      rc = 1;
    }
  }else

  if( c=='s' && cli_strncmp(azArg[0], "schema", n)==0 ){
    ShellState data;
    char *zErrMsg = 0;
    const char *zDiv = "(";
    const char *zName = 0;
    int iSchema = 0;
    int bDebug = 0;
    int bNoSystemTabs = 0;
    int bIndent = 0;
    int ii;
    sqlite3_str *pSql;
    sqlite3_stmt *pStmt = 0;
 
    open_db(p, 0);
    memcpy(&data, p, sizeof(data));
    data.mode.spec.bTitles = QRF_No;
    data.mode.eMode = MODE_List;
    data.mode.spec.eText = QRF_TEXT_Plain;
    data.mode.spec.nCharLimit = 0;
    data.mode.spec.zRowSep = "\n";
    for(ii=1; ii<nArg; ii++){
      if( optionMatch(azArg[ii],"indent") ){
        bIndent = 1;
      }else if( optionMatch(azArg[ii],"debug") ){
        bDebug = 1;
      }else if( optionMatch(azArg[ii],"nosys") ){
        bNoSystemTabs = 1;
      }else if( azArg[ii][0]=='-' ){
        cli_printf(stderr,"Unknown option: \"%s\"\n", azArg[ii]);
        rc = 1;
        goto meta_command_exit;
      }else if( zName==0 ){
        zName = azArg[ii];
      }else{
        eputz("Usage: .schema ?--indent? ?--nosys? ?LIKE-PATTERN?\n");
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( zName!=0 ){
      int isSchema = sqlite3_strlike(zName, "sqlite_master", '\\')==0
                  || sqlite3_strlike(zName, "sqlite_schema", '\\')==0
                  || sqlite3_strlike(zName,"sqlite_temp_master", '\\')==0
                  || sqlite3_strlike(zName,"sqlite_temp_schema", '\\')==0;
      if( isSchema ){
        cli_printf(p->out,
                      "CREATE TABLE %ssqlite_schema (\n"
                      "  type text,\n"
                      "  name text,\n"
                      "  tbl_name text,\n"
                      "  rootpage integer,\n"
                      "  sql text\n"
                      ");\n",
               sqlite3_strlike("sqlite_t%",zName,0)==0 ? "temp." : ""
        );
      }
    }
    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
    if( rc ){
      shellDatabaseError(p->db);
      sqlite3_finalize(pStmt);
      
      rc = 1;
      goto meta_command_exit;
    }
    pSql = sqlite3_str_new(p->db);
    sqlite3_str_appendf(pSql, "SELECT sql FROM", 0);
    iSchema = 0;
    while( sqlite3_step(pStmt)==SQLITE_ROW ){
      const char *zDb = (const char*)sqlite3_column_text(pStmt, 1);
      char zScNum[30];
      sqlite3_snprintf(sizeof(zScNum), zScNum, "%d", ++iSchema);
      sqlite3_str_appendall(pSql, zDiv);
      zDiv = " UNION ALL ";
      if( sqlite3_stricmp(zDb, "main")==0 ){
        sqlite3_str_appendf(pSql,
            "SELECT shell_format_schema(shell_add_schema(sql,NULL,name),%d)",
            bIndent);
      }else{
        sqlite3_str_appendf(pSql,
            "SELECT shell_format_schema(shell_add_schema(sql,%Q,name),%d)",
            zDb, bIndent);
      }
      sqlite3_str_appendf(pSql,
         " AS sql, type, tbl_name, name, rowid, %d AS snum, %Q as sname",
         ++iSchema, zDb);
      sqlite3_str_appendf(pSql," FROM \"%w\".sqlite_schema", zDb);
    }
    sqlite3_finalize(pStmt);
#if !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS) \
 && !defined(SQLITE_OMIT_VIRTUALTABLE)
    if( zName ){
      sqlite3_str_appendall(pSql,
         " UNION ALL SELECT shell_module_schema(name),"
         " 'table', name, name, name, 9e+99, 'main' FROM pragma_module_list");
    }
#endif
    sqlite3_str_appendf(pSql, ") WHERE ", 0);
    if( zName ){
      int bGlob;
      bGlob = strchr(zName, '*') != 0 || strchr(zName, '?') != 0 ||
              strchr(zName, '[') != 0;
      if( strchr(zName, '.') ){
        sqlite3_str_appendall(pSql, "lower(format('%%s.%%s',sname,tbl_name))");
      }else{
        sqlite3_str_appendall(pSql, "lower(tbl_name)");
      }
      if( bGlob ){
        sqlite3_str_appendf(pSql, " GLOB %Q AND ", zName);
      }else{
        sqlite3_str_appendf(pSql, " LIKE %Q ESCAPE '\\' AND ", zName);
      }
    }
    if( bNoSystemTabs ){
      sqlite3_str_appendf(pSql, " name NOT LIKE 'sqlite__%%' ESCAPE '_' AND ");
    }
    sqlite3_str_appendf(pSql, "sql IS NOT NULL ORDER BY snum, rowid");
    if( bDebug ){
      cli_printf(p->out, "SQL: %s;\n", sqlite3_str_value(pSql));
    }else{
      rc = shell_exec(&data, sqlite3_str_value(pSql), &zErrMsg);
    }
    sqlite3_str_free(pSql);

    if( zErrMsg ){
      shellEmitError(zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }else if( rc != SQLITE_OK ){
      eputz("Error: querying schema information\n");
      rc = 1;
    }else{
      rc = 0;
    }
  }else

  if( (c=='s' && n==11 && cli_strncmp(azArg[0], "selecttrace", n)==0)
   || (c=='t' && n==9  && cli_strncmp(azArg[0], "treetrace", n)==0)
  ){
    unsigned int x = nArg>=2? (unsigned int)integerValue(azArg[1]) : 0xffffffff;
    sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 1, &x);
  }else

#if defined(SQLITE_ENABLE_SESSION)
  if( c=='s' && cli_strncmp(azArg[0],"session",n)==0 && n>=3 ){
    struct AuxDb *pAuxDb = p->pAuxDb;
    OpenSession *pSession = &pAuxDb->aSession[0];
    char **azCmd = &azArg[1];
    int iSes = 0;
    int nCmd = nArg - 1;
    int i;
    if( nArg<=1 ) goto session_syntax_error;
    open_db(p, 0);
    if( nArg>=3 ){
      for(iSes=0; iSes<pAuxDb->nSession; iSes++){
        if( cli_strcmp(pAuxDb->aSession[iSes].zName, azArg[1])==0 ) break;
      }
      if( iSes<pAuxDb->nSession ){
        pSession = &pAuxDb->aSession[iSes];
        azCmd++;
        nCmd--;
      }else{
        pSession = &pAuxDb->aSession[0];
        iSes = 0;
      }
    }

    /* .session attach TABLE
    ** Invoke the sqlite3session_attach() interface to attach a particular
    ** table so that it is never filtered.
    */
    if( cli_strcmp(azCmd[0],"attach")==0 ){
      if( nCmd!=2 ) goto session_syntax_error;
      if( pSession->p==0 ){
        session_not_open:
        eputz("ERROR: No sessions are open\n");
      }else{
        rc = sqlite3session_attach(pSession->p, azCmd[1]);
        if( rc ){
          cli_printf(stderr,
               "ERROR: sqlite3session_attach() returns %d\n",rc);
          rc = 0;
        }
      }
    }else

    /* .session changeset FILE
    ** .session patchset FILE
    ** Write a changeset or patchset into a file.  The file is overwritten.
    */
    if( cli_strcmp(azCmd[0],"changeset")==0
     || cli_strcmp(azCmd[0],"patchset")==0
    ){
      FILE *out = 0;
      failIfSafeMode(p, "cannot run \".session %s\" in safe mode", azCmd[0]);
      if( nCmd!=2 ) goto session_syntax_error;
      if( pSession->p==0 ) goto session_not_open;
      out = sqlite3_fopen(azCmd[1], "wb");
      if( out==0 ){
        cli_printf(stderr,"ERROR: cannot open \"%s\" for writing\n",
              azCmd[1]);
      }else{
        int szChng;
        void *pChng;
        if( azCmd[0][0]=='c' ){
          rc = sqlite3session_changeset(pSession->p, &szChng, &pChng);
        }else{
          rc = sqlite3session_patchset(pSession->p, &szChng, &pChng);
        }
        if( rc ){
          cli_printf(stdout, "Error: error code %d\n", rc);
          rc = 0;
        }
        if( pChng
          && fwrite(pChng, szChng, 1, out)!=1 ){
          cli_printf(stderr,
              "ERROR: Failed to write entire %d-byte output\n", szChng);
        }
        sqlite3_free(pChng);
        fclose(out);
      }
    }else

    /* .session close
    ** Close the identified session
    */
    if( cli_strcmp(azCmd[0], "close")==0 ){
      if( nCmd!=1 ) goto session_syntax_error;
      if( pAuxDb->nSession ){
        session_close(pSession);
        pAuxDb->aSession[iSes] = pAuxDb->aSession[--pAuxDb->nSession];
      }
    }else

    /* .session enable ?BOOLEAN?
    ** Query or set the enable flag
    */
    if( cli_strcmp(azCmd[0], "enable")==0 ){
      int ii;
      if( nCmd>2 ) goto session_syntax_error;
      ii = nCmd==1 ? -1 : booleanValue(azCmd[1]);
      if( pAuxDb->nSession ){
        ii = sqlite3session_enable(pSession->p, ii);
        cli_printf(p->out,
            "session %s enable flag = %d\n", pSession->zName, ii);
      }
    }else

    /* .session filter GLOB ....
    ** Set a list of GLOB patterns of table names to be excluded.
    */
    if( cli_strcmp(azCmd[0], "filter")==0 ){
      int ii;
      i64 nByte;
      if( nCmd<2 ) goto session_syntax_error;
      if( pAuxDb->nSession ){
        for(ii=0; ii<pSession->nFilter; ii++){
          sqlite3_free(pSession->azFilter[ii]);
        }
        sqlite3_free(pSession->azFilter);
        nByte = sizeof(pSession->azFilter[0])*(nCmd-1);
        pSession->azFilter = sqlite3_malloc64( nByte );
        shell_check_oom( pSession->azFilter );
        for(ii=1; ii<nCmd; ii++){
          char *x = pSession->azFilter[ii-1] = sqlite3_mprintf("%s", azCmd[ii]);
          shell_check_oom(x);
        }
        pSession->nFilter = ii-1;
      }
    }else

    /* .session indirect ?BOOLEAN?
    ** Query or set the indirect flag
    */
    if( cli_strcmp(azCmd[0], "indirect")==0 ){
      int ii;
      if( nCmd>2 ) goto session_syntax_error;
      ii = nCmd==1 ? -1 : booleanValue(azCmd[1]);
      if( pAuxDb->nSession ){
        ii = sqlite3session_indirect(pSession->p, ii);
        cli_printf(p->out,
            "session %s indirect flag = %d\n", pSession->zName, ii);
      }
    }else

    /* .session isempty
    ** Determine if the session is empty
    */
    if( cli_strcmp(azCmd[0], "isempty")==0 ){
      int ii;
      if( nCmd!=1 ) goto session_syntax_error;
      if( pAuxDb->nSession ){
        ii = sqlite3session_isempty(pSession->p);
        cli_printf(p->out,
             "session %s isempty flag = %d\n", pSession->zName, ii);
      }
    }else

    /* .session list
    ** List all currently open sessions
    */
    if( cli_strcmp(azCmd[0],"list")==0 ){
      for(i=0; i<pAuxDb->nSession; i++){
        cli_printf(p->out, "%d %s\n", i, pAuxDb->aSession[i].zName);
      }
    }else

    /* .session open DB NAME
    ** Open a new session called NAME on the attached database DB.
    ** DB is normally "main".
    */
    if( cli_strcmp(azCmd[0],"open")==0 ){
      char *zName;
      if( nCmd!=3 ) goto session_syntax_error;
      zName = azCmd[2];
      if( zName[0]==0 ) goto session_syntax_error;
      for(i=0; i<pAuxDb->nSession; i++){
        if( cli_strcmp(pAuxDb->aSession[i].zName,zName)==0 ){
          cli_printf(stderr,"Session \"%s\" already exists\n", zName);
          goto meta_command_exit;
        }
      }
      if( pAuxDb->nSession>=ArraySize(pAuxDb->aSession) ){
        cli_printf(stderr,
           "Maximum of %d sessions\n", ArraySize(pAuxDb->aSession));
        goto meta_command_exit;
      }
      pSession = &pAuxDb->aSession[pAuxDb->nSession];
      rc = sqlite3session_create(p->db, azCmd[1], &pSession->p);
      if( rc ){
        cli_printf(stderr,"Cannot open session: error code=%d\n", rc);
        rc = 0;
        goto meta_command_exit;
      }
      pSession->nFilter = 0;
      sqlite3session_table_filter(pSession->p, session_filter, pSession);
      pAuxDb->nSession++;
      pSession->zName = sqlite3_mprintf("%s", zName);
      shell_check_oom(pSession->zName);
    }else
    /* If no command name matches, show a syntax error */
    session_syntax_error:
    showHelp(p->out, "session");
  }else
#endif

#ifdef SQLITE_DEBUG
  /* Undocumented commands for internal testing.  Subject to change
  ** without notice. */
  if( c=='s' && n>=10 && cli_strncmp(azArg[0], "selftest-", 9)==0 ){
    if( cli_strncmp(azArg[0]+9, "boolean", n-9)==0 ){
      int i, v;
      for(i=1; i<nArg; i++){
        v = booleanValue(azArg[i]);
        cli_printf(p->out, "%s: %d 0x%x\n", azArg[i], v, v);
      }
    }
    if( cli_strncmp(azArg[0]+9, "integer", n-9)==0 ){
      int i; sqlite3_int64 v;
      for(i=1; i<nArg; i++){
        char zBuf[200];
        v = integerValue(azArg[i]);
        sqlite3_snprintf(sizeof(zBuf),zBuf,"%s: %lld 0x%llx\n", azArg[i],v,v);
        cli_puts(zBuf, p->out);
      }
    }
  }else
#endif

  if( c=='s' && n>=4 && cli_strncmp(azArg[0],"selftest",n)==0 ){
    int bIsInit = 0;         /* True to initialize the SELFTEST table */
    int bVerbose = 0;        /* Verbose output */
    int bSelftestExists;     /* True if SELFTEST already exists */
    int i, k;                /* Loop counters */
    int nTest = 0;           /* Number of tests runs */
    int nErr = 0;            /* Number of errors seen */
    ShellText str;           /* Answer for a query */
    sqlite3_stmt *pStmt = 0; /* Query against the SELFTEST table */

    open_db(p,0);
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' && z[1]=='-' ) z++;
      if( cli_strcmp(z,"-init")==0 ){
        bIsInit = 1;
      }else
      if( cli_strcmp(z,"-v")==0 ){
        bVerbose++;
      }else
      {
        cli_printf(stderr,
              "Unknown option \"%s\" on \"%s\"\n", azArg[i], azArg[0]);
        cli_puts("Should be one of: --init -v\n", stderr);
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( sqlite3_table_column_metadata(p->db,"main","selftest",0,0,0,0,0,0)
           != SQLITE_OK ){
      bSelftestExists = 0;
    }else{
      bSelftestExists = 1;
    }
    if( bIsInit ){
      createSelftestTable(p);
      bSelftestExists = 1;
    }
    initText(&str);
    appendText(&str, "x", 0);
    for(k=bSelftestExists; k>=0; k--){
      if( k==1 ){
        rc = sqlite3_prepare_v2(p->db,
            "SELECT tno,op,cmd,ans FROM selftest ORDER BY tno",
            -1, &pStmt, 0);
      }else{
        rc = sqlite3_prepare_v2(p->db,
          "VALUES(0,'memo','Missing SELFTEST table - default checks only',''),"
          "      (1,'run','PRAGMA integrity_check','ok')",
          -1, &pStmt, 0);
      }
      if( rc ){
        eputz("Error querying the selftest table\n");
        rc = 1;
        sqlite3_finalize(pStmt);
        goto meta_command_exit;
      }
      for(i=1; sqlite3_step(pStmt)==SQLITE_ROW; i++){
        int tno = sqlite3_column_int(pStmt, 0);
        const char *zOp = (const char*)sqlite3_column_text(pStmt, 1);
        const char *zSql = (const char*)sqlite3_column_text(pStmt, 2);
        const char *zAns = (const char*)sqlite3_column_text(pStmt, 3);

        if( zOp==0 ) continue;
        if( zSql==0 ) continue;
        if( zAns==0 ) continue;
        k = 0;
        if( bVerbose>0 ){
          cli_printf(stdout, "%d: %s %s\n", tno, zOp, zSql);
        }
        if( cli_strcmp(zOp,"memo")==0 ){
          cli_printf(p->out, "%s\n", zSql);
        }else
        if( cli_strcmp(zOp,"run")==0 ){
          char *zErrMsg = 0;
          str.n = 0;
          str.zTxt[0] = 0;
          rc = sqlite3_exec(p->db, zSql, captureOutputCallback, &str, &zErrMsg);
          nTest++;
          if( bVerbose ){
            cli_printf(p->out, "Result: %s\n", str.zTxt);
          }
          if( rc || zErrMsg ){
            nErr++;
            rc = 1;
            cli_printf(p->out, "%d: error-code-%d: %s\n", tno, rc,zErrMsg);
            sqlite3_free(zErrMsg);
          }else if( cli_strcmp(zAns,str.zTxt)!=0 ){
            nErr++;
            rc = 1;
            cli_printf(p->out, "%d: Expected: [%s]\n", tno, zAns);
            cli_printf(p->out, "%d:      Got: [%s]\n", tno, str.zTxt);
          }
        }
        else{
          cli_printf(stderr,
                "Unknown operation \"%s\" on selftest line %d\n", zOp, tno);
          rc = 1;
          break;
        }
      } /* End loop over rows of content from SELFTEST */
      sqlite3_finalize(pStmt);
    } /* End loop over k */
    freeText(&str);
    cli_printf(p->out, "%d errors out of %d tests\n", nErr, nTest);
  }else

  if( c=='s' && cli_strncmp(azArg[0], "separator", n)==0 ){
    if( nArg<2 || nArg>3 ){
      eputz("Usage: .separator COL ?ROW?\n");
      rc = 1;
    }
    if( nArg>=2 ){
      modeSetStr(&p->mode.spec.zColumnSep, azArg[1]);
    }
    if( nArg>=3 ){
      modeSetStr(&p->mode.spec.zRowSep,azArg[2]);
    }
  }else

  if( c=='s' && n>=4 && cli_strncmp(azArg[0],"sha3sum",n)==0 ){
    const char *zLike = 0;   /* Which table to checksum. 0 means everything */
    int i;                   /* Loop counter */
    int bSchema = 0;         /* Also hash the schema */
    int bSeparate = 0;       /* Hash each table separately */
    int iSize = 224;         /* Hash algorithm to use */
    int bDebug = 0;          /* Only show the query that would have run */
    sqlite3_stmt *pStmt;     /* For querying tables names */
    char *zSql;              /* SQL to be run */
    char *zSep;              /* Separator */
    ShellText sSql;          /* Complete SQL for the query to run the hash */
    ShellText sQuery;        /* Set of queries used to read all content */
    open_db(p, 0);
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' ){
        z++;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"schema")==0 ){
          bSchema = 1;
        }else
        if( cli_strcmp(z,"sha3-224")==0 || cli_strcmp(z,"sha3-256")==0
         || cli_strcmp(z,"sha3-384")==0 || cli_strcmp(z,"sha3-512")==0
        ){
          iSize = atoi(&z[5]);
        }else
        if( cli_strcmp(z,"debug")==0 ){
          bDebug = 1;
        }else
        {
          cli_printf(stderr,
                  "Unknown option \"%s\" on \"%s\"\n", azArg[i], azArg[0]);
          showHelp(p->out, azArg[0]);
          rc = 1;
          goto meta_command_exit;
        }
      }else if( zLike ){
        eputz("Usage: .sha3sum ?OPTIONS? ?LIKE-PATTERN?\n");
        rc = 1;
        goto meta_command_exit;
      }else{
        zLike = z;
        bSeparate = 1;
        if( sqlite3_strlike("sqlite\\_%", zLike, '\\')==0 ) bSchema = 1;
      }
    }
    if( bSchema ){
      zSql = "SELECT lower(name) as tname FROM sqlite_schema"
             " WHERE type='table' AND coalesce(rootpage,0)>1"
             " UNION ALL SELECT 'sqlite_schema'"
             " ORDER BY 1 collate nocase";
    }else{
      zSql = "SELECT lower(name) as tname FROM sqlite_schema"
             " WHERE type='table' AND coalesce(rootpage,0)>1"
             " AND name NOT LIKE 'sqlite__%' ESCAPE '_'"
             " ORDER BY 1 collate nocase";
    }
    sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    initText(&sQuery);
    initText(&sSql);
    appendText(&sSql, "WITH [sha3sum$query](a,b) AS(",0);
    zSep = "VALUES(";
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zTab = (const char*)sqlite3_column_text(pStmt,0);
      if( zTab==0 ) continue;
      if( zLike && sqlite3_strlike(zLike, zTab, 0)!=0 ) continue;
      if( cli_strncmp(zTab, "sqlite_",7)!=0 ){
        appendText(&sQuery,"SELECT * FROM ", 0);
        appendText(&sQuery,zTab,'"');
        appendText(&sQuery," NOT INDEXED;", 0);
      }else if( cli_strcmp(zTab, "sqlite_schema")==0 ){
        appendText(&sQuery,"SELECT type,name,tbl_name,sql FROM sqlite_schema"
                           " ORDER BY name;", 0);
      }else if( cli_strcmp(zTab, "sqlite_sequence")==0 ){
        appendText(&sQuery,"SELECT name,seq FROM sqlite_sequence"
                           " ORDER BY name;", 0);
      }else if( cli_strcmp(zTab, "sqlite_stat1")==0 ){
        appendText(&sQuery,"SELECT tbl,idx,stat FROM sqlite_stat1"
                           " ORDER BY tbl,idx;", 0);
      }else if( cli_strcmp(zTab, "sqlite_stat4")==0 ){
        appendText(&sQuery, "SELECT * FROM ", 0);
        appendText(&sQuery, zTab, 0);
        appendText(&sQuery, " ORDER BY tbl, idx, rowid;\n", 0);
      }
      appendText(&sSql, zSep, 0);
      appendText(&sSql, sQuery.zTxt, '\'');
      sQuery.n = 0;
      appendText(&sSql, ",", 0);
      appendText(&sSql, zTab, '\'');
      zSep = "),(";
    }
    sqlite3_finalize(pStmt);
    if( bSeparate ){
      zSql = sqlite3_mprintf(
          "%s))"
          " SELECT lower(hex(sha3_query(a,%d))) AS hash, b AS label"
          "   FROM [sha3sum$query]",
          sSql.zTxt, iSize);
    }else{
      zSql = sqlite3_mprintf(
          "%s))"
          " SELECT lower(hex(sha3_query(group_concat(a,''),%d))) AS hash"
          "   FROM [sha3sum$query]",
          sSql.zTxt, iSize);
    }
    shell_check_oom(zSql);
    freeText(&sQuery);
    freeText(&sSql);
    if( bDebug ){
      cli_printf(p->out, "%s\n", zSql);
    }else{
      shell_exec(p, zSql, 0);
    }
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && !defined(SQLITE_OMIT_VIRTUALTABLE)
    {
      int lrc;
      char *zRevText = /* Query for reversible to-blob-to-text check */
        "SELECT lower(name) as tname FROM sqlite_schema\n"
        "WHERE type='table' AND coalesce(rootpage,0)>1\n"
        "AND name NOT LIKE 'sqlite__%%' ESCAPE '_'%s\n"
        "ORDER BY 1 collate nocase";
      zRevText = sqlite3_mprintf(zRevText, zLike? " AND name LIKE $tspec" : "");
      zRevText = sqlite3_mprintf(
          /* lower-case query is first run, producing upper-case query. */
          "with tabcols as materialized(\n"
          "select tname, cname\n"
          "from ("
          " select printf('\"%%w\"',ss.tname) as tname,"
          " printf('\"%%w\"',ti.name) as cname\n"
          " from (%z) ss\n inner join pragma_table_info(tname) ti))\n"
          "select 'SELECT total(bad_text_count) AS bad_text_count\n"
          "FROM ('||group_concat(query, ' UNION ALL ')||')' as btc_query\n"
          " from (select 'SELECT COUNT(*) AS bad_text_count\n"
          "FROM '||tname||' WHERE '\n"
          "||group_concat('CAST(CAST('||cname||' AS BLOB) AS TEXT)<>'||cname\n"
          "|| ' AND typeof('||cname||')=''text'' ',\n"
          "' OR ') as query, tname from tabcols group by tname)"
          , zRevText);
      shell_check_oom(zRevText);
      if( bDebug ) cli_printf(p->out, "%s\n", zRevText);
      lrc = sqlite3_prepare_v2(p->db, zRevText, -1, &pStmt, 0);
      if( lrc!=SQLITE_OK ){
        /* assert(lrc==SQLITE_NOMEM); // might also be SQLITE_ERROR if the
        ** user does cruel and unnatural things like ".limit expr_depth 0". */
        rc = 1;
      }else{
        if( zLike ) sqlite3_bind_text(pStmt,1,zLike,-1,SQLITE_STATIC);
        lrc = SQLITE_ROW==sqlite3_step(pStmt);
        if( lrc ){
          const char *zGenQuery = (char*)sqlite3_column_text(pStmt,0);
          sqlite3_stmt *pCheckStmt;
          lrc = sqlite3_prepare_v2(p->db, zGenQuery, -1, &pCheckStmt, 0);
          if( bDebug ) cli_printf(p->out, "%s\n", zGenQuery);
          if( lrc!=SQLITE_OK ){
            rc = 1;
          }else{
            if( SQLITE_ROW==sqlite3_step(pCheckStmt) ){
              double countIrreversible = sqlite3_column_double(pCheckStmt, 0);
              if( countIrreversible>0 ){
                int sz = (int)(countIrreversible + 0.5);
                cli_printf(stderr,
                      "Digest includes %d invalidly encoded text field%s.\n",
                      sz, (sz>1)? "s": "");
              }
            }
            sqlite3_finalize(pCheckStmt);
          }
          sqlite3_finalize(pStmt);
        }
      }
      if( rc ) eputz(".sha3sum failed.\n");
      sqlite3_free(zRevText);
    }
#endif /* !defined(*_OMIT_SCHEMA_PRAGMAS) && !defined(*_OMIT_VIRTUALTABLE) */
    sqlite3_free(zSql);
  }else

#if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
  if( c=='s'
   && (cli_strncmp(azArg[0], "shell", n)==0
       || cli_strncmp(azArg[0],"system",n)==0)
  ){
    char *zCmd;
    int i, x;
    failIfSafeMode(p, "cannot run .%s in safe mode", azArg[0]);
    if( nArg<2 ){
      eputz("Usage: .system COMMAND\n");
      rc = 1;
      goto meta_command_exit;
    }
    zCmd = sqlite3_mprintf(strchr(azArg[1],' ')==0?"%s":"\"%s\"", azArg[1]);
    for(i=2; i<nArg && zCmd!=0; i++){
      zCmd = sqlite3_mprintf(strchr(azArg[i],' ')==0?"%z %s":"%z \"%s\"",
                             zCmd, azArg[i]);
    }
    /*consoleRestore();*/
    x = zCmd!=0 ? system(zCmd) : 1;
    /*consoleRenewSetup();*/
    sqlite3_free(zCmd);
    if( x ) cli_printf(stderr,"System command returns %d\n", x);
  }else
#endif /* !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='s' && cli_strncmp(azArg[0], "show", n)==0 ){
    static const char *azBool[] = { "off", "on", "trigger", "full"};
    const char *zOut;
    int i;
    if( nArg!=1 ){
      eputz("Usage: .show\n");
      rc = 1;
      goto meta_command_exit;
    }
    cli_printf(p->out, "%12.12s: %s\n","echo", 
            azBool[(p->mode.mFlags & MFLG_ECHO)!=0]);
    cli_printf(p->out, "%12.12s: %s\n","eqp", azBool[p->mode.autoEQP&3]);
    cli_printf(p->out, "%12.12s: %s\n","explain",
                             p->mode.autoExplain ? "auto" : "off");
    cli_printf(p->out, "%12.12s: %s\n","headers",
          azBool[p->mode.spec.bTitles==QRF_Yes]);
    if( p->mode.spec.eStyle==QRF_STYLE_Column
     || p->mode.spec.eStyle==QRF_STYLE_Box
     || p->mode.spec.eStyle==QRF_STYLE_Table
     || p->mode.spec.eStyle==QRF_STYLE_Markdown
    ){
      cli_printf(p->out,
            "%12.12s: %s --wrap %d --wordwrap %s --%squote\n", "mode",
            aModeInfo[p->mode.eMode].zName, p->mode.spec.nWrap,
            p->mode.spec.bWordWrap==QRF_Yes ? "on" : "off",
            p->mode.spec.eText==QRF_TEXT_Sql ? "" : "no");
    }else{
      cli_printf(p->out, "%12.12s: %s\n","mode", 
                 aModeInfo[p->mode.eMode].zName);
    }
    cli_printf(p->out, "%12.12s: ", "nullvalue");
    output_c_string(p->out, p->mode.spec.zNull);
    cli_puts("\n", p->out);
    cli_printf(p->out, "%12.12s: %s\n","output",
          strlen30(p->outfile) ? p->outfile : "stdout");
    cli_printf(p->out, "%12.12s: ", "colseparator");
    output_c_string(p->out, p->mode.spec.zColumnSep);
    cli_puts("\n", p->out);
    cli_printf(p->out, "%12.12s: ", "rowseparator");
    output_c_string(p->out, p->mode.spec.zRowSep);
    cli_puts("\n", p->out);
    switch( p->statsOn ){
      case 0:  zOut = "off";     break;
      default: zOut = "on";      break;
      case 2:  zOut = "stmt";    break;
      case 3:  zOut = "vmstep";  break;
    }
    cli_printf(p->out, "%12.12s: %s\n","stats", zOut);
    cli_printf(p->out, "%12.12s: ", "width");
    for(i=0; i<p->mode.spec.nWidth; i++){
      cli_printf(p->out, "%d ", (int)p->mode.spec.aWidth[i]);
    }
    cli_puts("\n", p->out);
    cli_printf(p->out, "%12.12s: %s\n", "filename",
          p->pAuxDb->zDbFilename ? p->pAuxDb->zDbFilename : "");
  }else

  if( c=='s' && cli_strncmp(azArg[0], "stats", n)==0 ){
    if( nArg==2 ){
      if( cli_strcmp(azArg[1],"stmt")==0 ){
        p->statsOn = 2;
      }else if( cli_strcmp(azArg[1],"vmstep")==0 ){
        p->statsOn = 3;
      }else{
        p->statsOn = (u8)booleanValue(azArg[1]);
      }
    }else if( nArg==1 ){
      display_stats(p->db, p, 0);
    }else{
      eputz("Usage: .stats ?on|off|stmt|vmstep?\n");
      rc = 1;
    }
  }else

  if( (c=='t' && n>1 && cli_strncmp(azArg[0], "tables", n)==0) ){
    sqlite3_stmt *pStmt;
    sqlite3_str *pSql;
    const char *zPattern = nArg>1 ? azArg[1] : 0;

    open_db(p, 0);
    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
    if( rc ){
      sqlite3_finalize(pStmt);
      return shellDatabaseError(p->db);
    }

    pSql = sqlite3_str_new(p->db);
    while( sqlite3_step(pStmt)==SQLITE_ROW ){
      const char *zDbName = (const char*)sqlite3_column_text(pStmt, 1);
      if( zDbName==0 ) continue;
      if( sqlite3_str_length(pSql) ){
        sqlite3_str_appendall(pSql, " UNION ALL ");
      }
      if( sqlite3_stricmp(zDbName, "main")==0 ){
        sqlite3_str_appendall(pSql, "SELECT name FROM ");
      }else{
        sqlite3_str_appendf(pSql, "SELECT %Q||'.'||name FROM ", zDbName);
      }
      sqlite3_str_appendf(pSql, "\"%w\".sqlite_schema", zDbName);
      sqlite3_str_appendf(pSql,
          " WHERE type IN ('table','view')"
          "   AND name NOT LIKE 'sqlite__%%' ESCAPE '_'"
      );
      if( zPattern ){
        sqlite3_str_appendf(pSql," AND name LIKE %Q", zPattern);
      }
    }
    rc = sqlite3_finalize(pStmt);
    if( rc==SQLITE_OK ){
      sqlite3_str_appendall(pSql, " ORDER BY 1");
    }

    /* Run the SQL statement in "split" mode. */
    modePush(p);
    modeChange(p, MODE_Split);
    shell_exec(p, sqlite3_str_value(pSql), 0);
    sqlite3_str_free(pSql);
    modePop(p);
    if( rc ) return shellDatabaseError(p->db);
  }else

  /* Set the p->zTestcase name and begin redirecting output into
  ** the cli_output_capture sqlite3_str */
  if( c=='t' && cli_strcmp(azArg[0],"testcase")==0 ){
    rc = dotCmdTestcase(p);
  }else

#ifndef SQLITE_UNTESTABLE
  if( c=='t' && n>=8 && cli_strncmp(azArg[0], "testctrl", n)==0 ){
    static const struct {
       const char *zCtrlName;   /* Name of a test-control option */
       int ctrlCode;            /* Integer code for that option */
       int unSafe;              /* Not valid unless --unsafe-testing */
       const char *zUsage;      /* Usage notes */
    } aCtrl[] = {
    {"always",             SQLITE_TESTCTRL_ALWAYS, 1,     "BOOLEAN"         },
    {"assert",             SQLITE_TESTCTRL_ASSERT, 1,     "BOOLEAN"         },
  /*{"benign_malloc_hooks",SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS,1, ""        },*/
    {"bitvec_test",        SQLITE_TESTCTRL_BITVEC_TEST, 1, "SIZE INT-ARRAY"},
    {"byteorder",          SQLITE_TESTCTRL_BYTEORDER, 0,  ""                },
    {"extra_schema_checks",SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS,0,"BOOLEAN"  },
    {"fault_install",      SQLITE_TESTCTRL_FAULT_INSTALL, 1,"args..."       },
    {"fk_no_action",       SQLITE_TESTCTRL_FK_NO_ACTION, 0, "BOOLEAN"       },
    {"imposter",         SQLITE_TESTCTRL_IMPOSTER,1,"SCHEMA ON/OFF ROOTPAGE"},
    {"internal_functions", SQLITE_TESTCTRL_INTERNAL_FUNCTIONS,0,""          },
    {"json_selfcheck",     SQLITE_TESTCTRL_JSON_SELFCHECK ,0,"BOOLEAN"      },
    {"localtime_fault",    SQLITE_TESTCTRL_LOCALTIME_FAULT,0,"BOOLEAN"      },
    {"never_corrupt",      SQLITE_TESTCTRL_NEVER_CORRUPT,1, "BOOLEAN"       },
    {"optimizations",      SQLITE_TESTCTRL_OPTIMIZATIONS,0,"DISABLE-MASK ..."},
#ifdef YYCOVERAGE
    {"parser_coverage",    SQLITE_TESTCTRL_PARSER_COVERAGE,0,""             },
#endif
    {"pending_byte",       SQLITE_TESTCTRL_PENDING_BYTE,1, "OFFSET  "       },
    {"prng_restore",       SQLITE_TESTCTRL_PRNG_RESTORE,0, ""               },
    {"prng_save",          SQLITE_TESTCTRL_PRNG_SAVE,   0, ""               },
    {"prng_seed",          SQLITE_TESTCTRL_PRNG_SEED,   0, "SEED ?db?"      },
    {"seek_count",         SQLITE_TESTCTRL_SEEK_COUNT,  0, ""               },
    {"sorter_mmap",        SQLITE_TESTCTRL_SORTER_MMAP, 0, "NMAX"           },
    {"tune",               SQLITE_TESTCTRL_TUNE,        1, "ID VALUE"       },
    };
    int testctrl = -1;
    int iCtrl = -1;
    int rc2 = 0;    /* 0: usage.  1: %d  2: %x  3: no-output */
    int isOk = 0;
    int i, n2;
    const char *zCmd = 0;

    open_db(p, 0);
    zCmd = nArg>=2 ? azArg[1] : "help";

    /* The argument can optionally begin with "-" or "--" */
    if( zCmd[0]=='-' && zCmd[1] ){
      zCmd++;
      if( zCmd[0]=='-' && zCmd[1] ) zCmd++;
    }

    /* --help lists all test-controls */
    if( cli_strcmp(zCmd,"help")==0 ){
      cli_puts("Available test-controls:\n", p->out);
      for(i=0; i<ArraySize(aCtrl); i++){
        if( aCtrl[i].unSafe && !ShellHasFlag(p,SHFLG_TestingMode) ) continue;
        cli_printf(p->out, "  .testctrl %s %s\n",
              aCtrl[i].zCtrlName, aCtrl[i].zUsage);
      }
      rc = 1;
      goto meta_command_exit;
    }

    /* convert testctrl text option to value. allow any unique prefix
    ** of the option name, or a numerical value. */
    n2 = strlen30(zCmd);
    for(i=0; i<ArraySize(aCtrl); i++){
      if( aCtrl[i].unSafe && !ShellHasFlag(p,SHFLG_TestingMode) ) continue;
      if( cli_strncmp(zCmd, aCtrl[i].zCtrlName, n2)==0 ){
        if( testctrl<0 ){
          testctrl = aCtrl[i].ctrlCode;
          iCtrl = i;
        }else{
          cli_printf(stderr,"Error: ambiguous test-control: \"%s\"\n"
                "Use \".testctrl --help\" for help\n", zCmd);
          rc = 1;
          goto meta_command_exit;
        }
      }
    }
    if( testctrl<0 ){
      cli_printf(stderr,"Error: unknown test-control: %s\n"
            "Use \".testctrl --help\" for help\n", zCmd);
    }else{
      switch(testctrl){

        /* Special processing for .testctrl opt MASK ...
        ** Each MASK argument can be one of:
        **
        **      +LABEL       Enable the named optimization 
        **
        **      -LABEL       Disable the named optimization
        **
        **      INTEGER      Mask of optimizations to disable
        */
        case SQLITE_TESTCTRL_OPTIMIZATIONS: {
          static const struct {
             unsigned int mask;    /* Mask for this optimization */
             unsigned int bDsply;  /* Display this on output */
             const char *zLabel;   /* Name of optimization */
          } aLabel[] = {
            { 0x00000001, 1, "QueryFlattener" },
            { 0x00000001, 0, "Flatten" },
            { 0x00000002, 1, "WindowFunc" },
            { 0x00000004, 1, "GroupByOrder" },
            { 0x00000008, 1, "FactorOutConst" },
            { 0x00000010, 1, "DistinctOpt" },
            { 0x00000020, 1, "CoverIdxScan" },
            { 0x00000040, 1, "OrderByIdxJoin" },
            { 0x00000080, 1, "Transitive" },
            { 0x00000100, 1, "OmitNoopJoin" },
            { 0x00000200, 1, "CountOfView" },
            { 0x00000400, 1, "CursorHints" },
            { 0x00000800, 1, "Stat4" },
            { 0x00001000, 1, "PushDown" },
            { 0x00002000, 1, "SimplifyJoin" },
            { 0x00004000, 1, "SkipScan" },
            { 0x00008000, 1, "PropagateConst" },
            { 0x00010000, 1, "MinMaxOpt" },
            { 0x00020000, 1, "SeekScan" },
            { 0x00040000, 1, "OmitOrderBy" },
            { 0x00080000, 1, "BloomFilter" },
            { 0x00100000, 1, "BloomPulldown" },
            { 0x00200000, 1, "BalancedMerge" },
            { 0x00400000, 1, "ReleaseReg" },
            { 0x00800000, 1, "FlttnUnionAll" },
            { 0x01000000, 1, "IndexedEXpr" },
            { 0x02000000, 1, "Coroutines" },
            { 0x04000000, 1, "NullUnusedCols" },
            { 0x08000000, 1, "OnePass" },
            { 0x10000000, 1, "OrderBySubq" },
            { 0x20000000, 1, "StarQuery" },
            { 0x40000000, 1, "ExistsToJoin" },
            { 0xffffffff, 0, "All" },
          };
          unsigned int curOpt;
          unsigned int newOpt;
          unsigned int m;
          int ii;
          int nOff;
          sqlite3_test_control(SQLITE_TESTCTRL_GETOPT, p->db, &curOpt);
          newOpt = curOpt;
          for(ii=2; ii<nArg; ii++){
            const char *z = azArg[ii];
            int useLabel = 0;
            const char *zLabel = 0;
            if( (z[0]=='+'|| z[0]=='-') && !IsDigit(z[1]) ){
              useLabel = z[0];
              zLabel = &z[1];
            }else if( !IsDigit(z[0]) && z[0]!=0 && !IsDigit(z[1]) ){
              useLabel = '+';
              zLabel = z;
            }else{
              newOpt = (unsigned int)strtol(z,0,0);
            }
            if( useLabel ){
              int jj;
              for(jj=0; jj<ArraySize(aLabel); jj++){
                if( sqlite3_stricmp(zLabel, aLabel[jj].zLabel)==0 ) break;
              }
              if( jj>=ArraySize(aLabel) ){
                cli_printf(stderr,
                    "Error: no such optimization: \"%s\"\n", zLabel);
                cli_puts("Should be one of:", stderr);
                for(jj=0; jj<ArraySize(aLabel); jj++){
                  cli_printf(stderr," %s", aLabel[jj].zLabel);
                }
                cli_puts("\n", stderr);
                rc = 1;
                goto meta_command_exit;
              }
              if( useLabel=='+' ){
                newOpt &= ~aLabel[jj].mask;
              }else{
                newOpt |= aLabel[jj].mask;
              }
            }
          }
          if( curOpt!=newOpt ){
            sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,p->db,newOpt);
          }
          for(ii=nOff=0, m=1; ii<32; ii++, m <<= 1){
            if( m & newOpt ) nOff++;
          }
          if( nOff<12 ){
            cli_puts("+All", p->out);
            for(ii=0; ii<ArraySize(aLabel); ii++){
              if( !aLabel[ii].bDsply  ) continue;
              if( (newOpt & aLabel[ii].mask)!=0 ){
                cli_printf(p->out, " -%s", aLabel[ii].zLabel);
              }
            }
          }else{
            cli_puts("-All", p->out);
            for(ii=0; ii<ArraySize(aLabel); ii++){
              if( !aLabel[ii].bDsply  ) continue;
              if( (newOpt & aLabel[ii].mask)==0 ){
                cli_printf(p->out, " +%s", aLabel[ii].zLabel);
              }
            }
          }
          cli_puts("\n", p->out);
          rc2 = isOk = 3;
          break;
        }

        /* sqlite3_test_control(int, db, int) */
        case SQLITE_TESTCTRL_FK_NO_ACTION:
          if( nArg==3 ){
            unsigned int opt = (unsigned int)strtol(azArg[2], 0, 0);
            rc2 = sqlite3_test_control(testctrl, p->db, opt);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(int) */
        case SQLITE_TESTCTRL_PRNG_SAVE:
        case SQLITE_TESTCTRL_PRNG_RESTORE:
        case SQLITE_TESTCTRL_BYTEORDER:
          if( nArg==2 ){
            rc2 = sqlite3_test_control(testctrl);
            isOk = testctrl==SQLITE_TESTCTRL_BYTEORDER ? 1 : 3;
          }
          break;

        /* sqlite3_test_control(int, uint) */
        case SQLITE_TESTCTRL_PENDING_BYTE:
          if( nArg==3 ){
            unsigned int opt = (unsigned int)integerValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(int, int, sqlite3*) */
        case SQLITE_TESTCTRL_PRNG_SEED:
          if( nArg==3 || nArg==4 ){
            int ii = (int)integerValue(azArg[2]);
            sqlite3 *db;
            if( ii==0 && cli_strcmp(azArg[2],"random")==0 ){
              sqlite3_randomness(sizeof(ii),&ii);
              cli_printf(stdout, "-- random seed: %d\n", ii);
            }
            if( nArg==3 ){
              db = 0;
            }else{
              db = p->db;
              /* Make sure the schema has been loaded */
              sqlite3_table_column_metadata(db, 0, "x", 0, 0, 0, 0, 0, 0);
            }
            rc2 = sqlite3_test_control(testctrl, ii, db);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(int, int) */
        case SQLITE_TESTCTRL_ASSERT:
        case SQLITE_TESTCTRL_ALWAYS:
          if( nArg==3 ){
            int opt = booleanValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 1;
          }
          break;

        /* sqlite3_test_control(int, int) */
        case SQLITE_TESTCTRL_LOCALTIME_FAULT:
        case SQLITE_TESTCTRL_NEVER_CORRUPT:
          if( nArg==3 ){
            int opt = booleanValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(sqlite3*) */
        case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS:
          rc2 = sqlite3_test_control(testctrl, p->db);
          isOk = 3;
          break;

        case SQLITE_TESTCTRL_IMPOSTER:
          if( nArg==5 ){
            rc2 = sqlite3_test_control(testctrl, p->db,
                          azArg[2],
                          integerValue(azArg[3]),
                          integerValue(azArg[4]));
            isOk = 3;
          }
          break;

        case SQLITE_TESTCTRL_SEEK_COUNT: {
          u64 x = 0;
          rc2 = sqlite3_test_control(testctrl, p->db, &x);
          cli_printf(p->out, "%llu\n", x);
          isOk = 3;
          break;
        }

#ifdef YYCOVERAGE
        case SQLITE_TESTCTRL_PARSER_COVERAGE: {
          if( nArg==2 ){
            sqlite3_test_control(testctrl, p->out);
            isOk = 3;
          }
          break;
        }
#endif
#ifdef SQLITE_DEBUG
        case SQLITE_TESTCTRL_TUNE: {
          if( nArg==4 ){
            int id = (int)integerValue(azArg[2]);
            int val = (int)integerValue(azArg[3]);
            sqlite3_test_control(testctrl, id, &val);
            isOk = 3;
          }else if( nArg==3 ){
            int id = (int)integerValue(azArg[2]);
            sqlite3_test_control(testctrl, -id, &rc2);
            isOk = 1;
          }else if( nArg==2 ){
            int id = 1;
            while(1){
              int val = 0;
              rc2 = sqlite3_test_control(testctrl, -id, &val);
              if( rc2!=SQLITE_OK ) break;
              if( id>1 ) cli_puts("  ", p->out);
              cli_printf(p->out, "%d: %d", id, val);
              id++;
            }
            if( id>1 ) cli_puts("\n", p->out);
            isOk = 3;
          }
          break;
        }
#endif
        case SQLITE_TESTCTRL_SORTER_MMAP:
          if( nArg==3 ){
            int opt = (unsigned int)integerValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, p->db, opt);
            isOk = 3;
          }
          break;
        case SQLITE_TESTCTRL_JSON_SELFCHECK:
          if( nArg==2 ){
            rc2 = -1;
            isOk = 1;
          }else{
            rc2 = booleanValue(azArg[2]);
            isOk = 3;
          }
          sqlite3_test_control(testctrl, &rc2);
          break;
        case SQLITE_TESTCTRL_BITVEC_TEST: {
          /* Examples:
          **   .testctrl bitvec_test 100   6,1       -- Show BITVEC constants
          **   .testctrl bitvec_test 1000  1,12,7,3  -- Simple test
          **                         ----  --------
          **      size of Bitvec -----^        ^---  aOp array. 0 added at end.
          **
          ** See comments on sqlite3BitvecBuiltinTest() for more information
          ** about the aOp[] array.
          */
          int iSize;
          const char *zTestArg;
          int nOp;
          int ii, jj, x;
          int *aOp;
          if( nArg!=4 ){
            cli_printf(stderr,
              "ERROR - should be:  \".testctrl bitvec_test SIZE  INT-ARRAY\"\n"
            );
            rc = 1;
            goto meta_command_exit;
          }
          isOk = 3;
          iSize = (int)integerValue(azArg[2]);
          zTestArg = azArg[3];
          nOp = (int)strlen(zTestArg)+1;
          aOp = malloc( sizeof(int)*(nOp+1) );
          shell_check_oom(aOp);
          memset(aOp, 0, sizeof(int)*(nOp+1) );
          for(ii = jj = x = 0; zTestArg[ii]!=0; ii++){
            if( IsDigit(zTestArg[ii]) ){
              x = x*10 + zTestArg[ii] - '0';
            }else{
              aOp[jj++] = x;
              x = 0;
            }
          }
          aOp[jj] = x;
          x = sqlite3_test_control(testctrl, iSize, aOp);
          cli_printf(p->out, "result: %d\n", x);
          free(aOp);
          break;
        }
        case SQLITE_TESTCTRL_FAULT_INSTALL: {
          int kk;
          int bShowHelp = nArg<=2;
          isOk = 3;
          for(kk=2; kk<nArg; kk++){
            const char *z = azArg[kk];
            if( z[0]=='-' && z[1]=='-' ) z++;
            if( cli_strcmp(z,"off")==0 ){
              sqlite3_test_control(testctrl, 0);
            }else if( cli_strcmp(z,"on")==0 ){
              faultsim_state.iCnt = faultsim_state.nSkip;
              if( faultsim_state.iErr==0 ) faultsim_state.iErr = 1;
              faultsim_state.nHit = 0;
              sqlite3_test_control(testctrl, faultsim_callback);
            }else if( cli_strcmp(z,"reset")==0 ){
              faultsim_state.iCnt = faultsim_state.nSkip;
              faultsim_state.nHit = 0;
              sqlite3_test_control(testctrl, faultsim_callback);
            }else if( cli_strcmp(z,"status")==0 ){
              cli_printf(p->out, "faultsim.iId:       %d\n",
                              faultsim_state.iId);
              cli_printf(p->out, "faultsim.iErr:      %d\n",
                              faultsim_state.iErr);
              cli_printf(p->out, "faultsim.iCnt:      %d\n",
                              faultsim_state.iCnt);
              cli_printf(p->out, "faultsim.nHit:      %d\n",
                              faultsim_state.nHit);
              cli_printf(p->out, "faultsim.iInterval: %d\n",
                              faultsim_state.iInterval);
              cli_printf(p->out, "faultsim.eVerbose:  %d\n",
                              faultsim_state.eVerbose);
              cli_printf(p->out, "faultsim.nRepeat:   %d\n",
                              faultsim_state.nRepeat);
              cli_printf(p->out, "faultsim.nSkip:     %d\n",
                              faultsim_state.nSkip);
            }else if( cli_strcmp(z,"-v")==0 ){
              if( faultsim_state.eVerbose<2 ) faultsim_state.eVerbose++;
            }else if( cli_strcmp(z,"-q")==0 ){
              if( faultsim_state.eVerbose>0 ) faultsim_state.eVerbose--;
            }else if( cli_strcmp(z,"-id")==0 && kk+1<nArg ){
              faultsim_state.iId = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-errcode")==0 && kk+1<nArg ){
              faultsim_state.iErr = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-interval")==0 && kk+1<nArg ){
              faultsim_state.iInterval = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-repeat")==0 && kk+1<nArg ){
              faultsim_state.nRepeat = atoi(azArg[++kk]);
           }else if( cli_strcmp(z,"-skip")==0 && kk+1<nArg ){
              faultsim_state.nSkip = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-?")==0 || sqlite3_strglob("*help*",z)==0){
              bShowHelp = 1;
            }else{
              cli_printf(stderr,
                  "Unrecognized fault_install argument: \"%s\"\n",
                  azArg[kk]);
              rc = 1;
              bShowHelp = 1;
              break;
            }
          }
          if( bShowHelp ){
            cli_puts(
               "Usage: .testctrl fault_install ARGS\n"
               "Possible arguments:\n"
               "   off               Disable faultsim\n"
               "   on                Activate faultsim\n"
               "   reset             Reset the trigger counter\n"
               "   status            Show current status\n"
               "   -v                Increase verbosity\n"
               "   -q                Decrease verbosity\n"
               "   --errcode N       When triggered, return N as error code\n"
               "   --id ID           Trigger only for the ID specified\n"
               "   --interval N      Trigger only after every N-th call\n"
               "   --repeat N        Turn off after N hits.  0 means never\n"
               "   --skip N          Skip the first N encounters\n"
               ,p->out
            );
          }
          break;
        }
      }
    }
    if( isOk==0 && iCtrl>=0 ){
      cli_printf(p->out,
          "Usage: .testctrl %s %s\n", zCmd,aCtrl[iCtrl].zUsage);
      rc = 1;
    }else if( isOk==1 ){
      cli_printf(p->out, "%d\n", rc2);
    }else if( isOk==2 ){
      cli_printf(p->out, "0x%08x\n", rc2);
    }
  }else
#endif /* !defined(SQLITE_UNTESTABLE) */

  if( c=='t' && n>4 && cli_strncmp(azArg[0], "timeout", n)==0 ){
    open_db(p, 0);
    sqlite3_busy_timeout(p->db, nArg>=2 ? (int)integerValue(azArg[1]) : 0);
  }else

  if( c=='t' && n>=5 && cli_strncmp(azArg[0], "timer", n)==0 ){
    if( nArg==2 ){
      if( cli_strcmp(azArg[1],"once")==0 ){
        p->enableTimer = 1;
      }else{
        p->enableTimer = 2*booleanValue(azArg[1]);
      }
      if( p->enableTimer && !HAS_TIMER ){
        eputz("Error: timer not available on this system.\n");
        p->enableTimer = 0;
      }
    }else{
      eputz("Usage: .timer on|off|once\n");
      rc = 1;
    }
  }else

#ifndef SQLITE_OMIT_TRACE
  if( c=='t' && cli_strncmp(azArg[0], "trace", n)==0 ){
    int mType = 0;
    int jj;
    open_db(p, 0);
    for(jj=1; jj<nArg; jj++){
      const char *z = azArg[jj];
      if( z[0]=='-' ){
        if( optionMatch(z, "expanded") ){
          p->eTraceType = SHELL_TRACE_EXPANDED;
        }
#ifdef SQLITE_ENABLE_NORMALIZE
        else if( optionMatch(z, "normalized") ){
          p->eTraceType = SHELL_TRACE_NORMALIZED;
        }
#endif
        else if( optionMatch(z, "plain") ){
          p->eTraceType = SHELL_TRACE_PLAIN;
        }
        else if( optionMatch(z, "profile") ){
          mType |= SQLITE_TRACE_PROFILE;
        }
        else if( optionMatch(z, "row") ){
          mType |= SQLITE_TRACE_ROW;
        }
        else if( optionMatch(z, "stmt") ){
          mType |= SQLITE_TRACE_STMT;
        }
        else if( optionMatch(z, "close") ){
          mType |= SQLITE_TRACE_CLOSE;
        }
        else {
          cli_printf(stderr,"Unknown option \"%s\" on \".trace\"\n", z);
          rc = 1;
          goto meta_command_exit;
        }
      }else{
        output_file_close(p->traceOut);
        p->traceOut = output_file_open(p, z);
      }
    }
    if( p->traceOut==0 ){
      sqlite3_trace_v2(p->db, 0, 0, 0);
    }else{
      if( mType==0 ) mType = SQLITE_TRACE_STMT;
      sqlite3_trace_v2(p->db, mType, sql_trace_callback, p);
    }
  }else
#endif /* !defined(SQLITE_OMIT_TRACE) */

#if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_VIRTUALTABLE)
  if( c=='u' && cli_strncmp(azArg[0], "unmodule", n)==0 ){
    int ii;
    int lenOpt;
    char *zOpt;
    if( nArg<2 ){
      eputz("Usage: .unmodule [--allexcept] NAME ...\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    zOpt = azArg[1];
    if( zOpt[0]=='-' && zOpt[1]=='-' && zOpt[2]!=0 ) zOpt++;
    lenOpt = (int)strlen(zOpt);
    if( lenOpt>=3 && cli_strncmp(zOpt, "-allexcept",lenOpt)==0 ){
      assert( azArg[nArg]==0 );
      sqlite3_drop_modules(p->db, nArg>2 ? (const char**)(azArg+2) : 0);
    }else{
      for(ii=1; ii<nArg; ii++){
        sqlite3_create_module(p->db, azArg[ii], 0, 0);
      }
    }
  }else
#endif

  if( c=='v' && cli_strncmp(azArg[0], "version", n)==0 ){
    char *zPtrSz = sizeof(void*)==8 ? "64-bit" : "32-bit";
    cli_printf(p->out, "SQLite %s %s\n" /*extra-version-info*/,
          sqlite3_libversion(), sqlite3_sourceid());
#if SQLITE_HAVE_ZLIB
    cli_printf(p->out, "zlib version %s\n", zlibVersion());
#endif
#define CTIMEOPT_VAL_(opt) #opt
#define CTIMEOPT_VAL(opt) CTIMEOPT_VAL_(opt)
#if defined(__clang__) && defined(__clang_major__)
    cli_printf(p->out, "clang-" CTIMEOPT_VAL(__clang_major__) "."
          CTIMEOPT_VAL(__clang_minor__) "."
          CTIMEOPT_VAL(__clang_patchlevel__) " (%s)\n", zPtrSz);
#elif defined(_MSC_VER)
    cli_printf(p->out, "msvc-" CTIMEOPT_VAL(_MSC_VER) " (%s)\n", zPtrSz);
#elif defined(__GNUC__) && defined(__VERSION__)
    cli_printf(p->out, "gcc-" __VERSION__ " (%s)\n", zPtrSz);
#endif
  }else

  if( c=='v' && cli_strncmp(azArg[0], "vfsinfo", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";
    sqlite3_vfs *pVfs = 0;
    if( p->db ){
      sqlite3_file_control(p->db, zDbName, SQLITE_FCNTL_VFS_POINTER, &pVfs);
      if( pVfs ){
        cli_printf(p->out, "vfs.zName      = \"%s\"\n", pVfs->zName);
        cli_printf(p->out, "vfs.iVersion   = %d\n", pVfs->iVersion);
        cli_printf(p->out, "vfs.szOsFile   = %d\n", pVfs->szOsFile);
        cli_printf(p->out, "vfs.mxPathname = %d\n", pVfs->mxPathname);
      }
    }
  }else

  if( c=='v' && cli_strncmp(azArg[0], "vfslist", n)==0 ){
    sqlite3_vfs *pVfs;
    sqlite3_vfs *pCurrent = 0;
    if( p->db ){
      sqlite3_file_control(p->db, "main", SQLITE_FCNTL_VFS_POINTER, &pCurrent);
    }
    for(pVfs=sqlite3_vfs_find(0); pVfs; pVfs=pVfs->pNext){
      cli_printf(p->out, "vfs.zName      = \"%s\"%s\n", pVfs->zName,
            pVfs==pCurrent ? "  <--- CURRENT" : "");
      cli_printf(p->out, "vfs.iVersion   = %d\n", pVfs->iVersion);
      cli_printf(p->out, "vfs.szOsFile   = %d\n", pVfs->szOsFile);
      cli_printf(p->out, "vfs.mxPathname = %d\n", pVfs->mxPathname);
      if( pVfs->pNext ){
        cli_puts("-----------------------------------\n", p->out);
      }
    }
  }else

  if( c=='v' && cli_strncmp(azArg[0], "vfsname", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";
    char *zVfsName = 0;
    if( p->db ){
      sqlite3_file_control(p->db, zDbName, SQLITE_FCNTL_VFSNAME, &zVfsName);
      if( zVfsName ){
        cli_printf(p->out, "%s\n", zVfsName);
        sqlite3_free(zVfsName);
      }
    }
  }else

  if( c=='w' && cli_strncmp(azArg[0], "wheretrace", n)==0 ){
    unsigned int x = nArg>=2? (unsigned int)integerValue(azArg[1]) : 0xffffffff;
    sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 3, &x);
  }else

  if( c=='w' && cli_strncmp(azArg[0], "width", n)==0 ){
    int j;
    p->mode.spec.nWidth = nArg-1;
    p->mode.spec.aWidth = realloc(p->mode.spec.aWidth,
                                  (p->mode.spec.nWidth+1)*sizeof(short int));
    shell_check_oom(p->mode.spec.aWidth);
    for(j=1; j<nArg; j++){
      i64 w = integerValue(azArg[j]);
      if( w < -QRF_MAX_WIDTH ) w = -QRF_MAX_WIDTH;
      if( w > QRF_MAX_WIDTH ) w = QRF_MAX_WIDTH;
      p->mode.spec.aWidth[j-1] = (short int)w;
    }
  }else

  {
    cli_printf(stderr,"Error: unknown command or invalid arguments: "
          " \"%s\". Enter \".help\" for help\n", azArg[0]);
    rc = 1;
  }

meta_command_exit:
  if( p->nPopOutput ){
    p->nPopOutput--;
    if( p->nPopOutput==0 ) output_reset(p);
  }
  p->bSafeMode = p->bSafeModePersist;
  p->dot.nArg = 0;
  return rc;
}

/* Line scan result and intermediate states (supporting scan resumption)
*/
#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif
typedef enum {
  QSS_HasDark = 1<<CHAR_BIT, QSS_EndingSemi = 2<<CHAR_BIT,
  QSS_CharMask = (1<<CHAR_BIT)-1, QSS_ScanMask = 3<<CHAR_BIT,
  QSS_Start = 0
} QuickScanState;
#define QSS_SETV(qss, newst) ((newst) | ((qss) & QSS_ScanMask))
#define QSS_INPLAIN(qss) (((qss)&QSS_CharMask)==QSS_Start)
#define QSS_PLAINWHITE(qss) (((qss)&~QSS_EndingSemi)==QSS_Start)
#define QSS_PLAINDARK(qss) (((qss)&~QSS_EndingSemi)==QSS_HasDark)
#define QSS_SEMITERM(qss) (((qss)&~QSS_HasDark)==QSS_EndingSemi)

/*
** Scan line for classification to guide shell's handling.
** The scan is resumable for subsequent lines when prior
** return values are passed as the 2nd argument.
*/
static QuickScanState quickscan(char *zLine, QuickScanState qss,
                                SCAN_TRACKER_REFTYPE pst){
  char cin;
  char cWait = (char)qss; /* intentional narrowing loss */
  if( cWait==0 ){
  PlainScan:
    while( (cin = *zLine++)!=0 ){
      if( IsSpace(cin) )
        continue;
      switch (cin){
      case '-':
        if( *zLine!='-' )
          break;
        while((cin = *++zLine)!=0 )
          if( cin=='\n')
            goto PlainScan;
        return qss;
      case ';':
        qss |= QSS_EndingSemi;
        continue;
      case '/':
        if( *zLine=='*' ){
          ++zLine;
          cWait = '*';
          CONTINUE_PROMPT_AWAITS(pst, "/*");
          qss = QSS_SETV(qss, cWait);
          goto TermScan;
        }
        break;
      case '[':
        cin = ']';
        deliberate_fall_through; /* FALLTHRU */
      case '`': case '\'': case '"':
        cWait = cin;
        qss = QSS_HasDark | cWait;
        CONTINUE_PROMPT_AWAITC(pst, cin);
        goto TermScan;
      case '(':
        CONTINUE_PAREN_INCR(pst, 1);
        break;
      case ')':
        CONTINUE_PAREN_INCR(pst, -1);
        break;
      default:
        break;
      }
      qss = (qss & ~QSS_EndingSemi) | QSS_HasDark;
    }
  }else{
  TermScan:
    while( (cin = *zLine++)!=0 ){
      if( cin==cWait ){
        switch( cWait ){
        case '*':
          if( *zLine != '/' )
            continue;
          ++zLine;
          CONTINUE_PROMPT_AWAITC(pst, 0);
          qss = QSS_SETV(qss, 0);
          goto PlainScan;
        case '`': case '\'': case '"':
          if(*zLine==cWait){
            /* Swallow doubled end-delimiter.*/
            ++zLine;
            continue;
          }
          deliberate_fall_through; /* FALLTHRU */
        case ']':
          CONTINUE_PROMPT_AWAITC(pst, 0);
          qss = QSS_SETV(qss, 0);
          goto PlainScan;
        default: assert(0);
        }
      }
    }
  }
  return qss;
}

/*
** Return TRUE if the line typed in is an SQL command terminator other
** than a semi-colon.  The SQL Server style "go" command is understood
** as is the Oracle "/".
*/
static int line_is_command_terminator(char *zLine){
  while( IsSpace(zLine[0]) ){ zLine++; };
  if( zLine[0]=='/' )
    zLine += 1; /* Oracle */
  else if ( ToLower(zLine[0])=='g' && ToLower(zLine[1])=='o' )
    zLine += 2; /* SQL Server */
  else
    return 0;
  return quickscan(zLine, QSS_Start, 0)==QSS_Start;
}

/*
** The CLI needs a working sqlite3_complete() to work properly.  So error
** out of the build if compiling with SQLITE_OMIT_COMPLETE.
*/
#ifdef SQLITE_OMIT_COMPLETE
# error the CLI application is incompatible with SQLITE_OMIT_COMPLETE.
#endif

/*
** Return true if zSql is a complete SQL statement.  Return false if it
** ends in the middle of a string literal or C-style comment.
*/
static int line_is_complete(char *zSql, int nSql){
  int rc;
  if( zSql==0 ) return 1;
  zSql[nSql] = ';';
  zSql[nSql+1] = 0;
  rc = sqlite3_complete(zSql);
  zSql[nSql] = 0;
  return rc;
}

/*
** This function is called after processing each line of SQL in the
** runOneSqlLine() function. Its purpose is to detect scenarios where
** defensive mode should be automatically turned off. Specifically, when
**
**   1. The first line of input is "PRAGMA foreign_keys=OFF;",
**   2. The second line of input is "BEGIN TRANSACTION;",
**   3. The database is empty, and
**   4. The shell is not running in --safe mode.
** 
** The implementation uses the ShellState.eRestoreState to maintain state:
**
**    0: Have not seen any SQL.
**    1: Have seen "PRAGMA foreign_keys=OFF;".
**    2-6: Currently running .dump transaction. If the "2" bit is set,
**         disable DEFENSIVE when done. If "4" is set, disable DQS_DDL.
**    7: Nothing left to do. This function becomes a no-op.
*/
static int doAutoDetectRestore(ShellState *p, const char *zSql){
  int rc = SQLITE_OK;

  if( p->eRestoreState<7 ){
    switch( p->eRestoreState ){
      case 0: {
        const char *zExpect = "PRAGMA foreign_keys=OFF;";
        assert( strlen(zExpect)==24 );
        if( p->bSafeMode==0
         && strlen(zSql)>=24
         && memcmp(zSql, zExpect, 25)==0
        ){
          p->eRestoreState = 1;
        }else{
          p->eRestoreState = 7;
        }
        break;
      };
  
      case 1: {
        int bIsDump = 0;
        const char *zExpect = "BEGIN TRANSACTION;";
        assert( strlen(zExpect)==18 );
        if( memcmp(zSql, zExpect, 19)==0 ){
          /* Now check if the database is empty. */
          const char *zQuery = "SELECT 1 FROM sqlite_schema LIMIT 1";
          sqlite3_stmt *pStmt = 0;
  
          bIsDump = 1;
          shellPrepare(p->db, &rc, zQuery, &pStmt);
          if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
            bIsDump = 0;
          }
          shellFinalize(&rc, pStmt);
        }
        if( bIsDump && rc==SQLITE_OK ){
          int bDefense = 0;
          int bDqsDdl = 0;
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, -1, &bDefense);
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DQS_DDL, -1, &bDqsDdl);
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 0, 0);
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DQS_DDL, 1, 0);
          p->eRestoreState = (bDefense ? 2 : 0) + (bDqsDdl ? 4 : 0);
        }else{
          p->eRestoreState = 7;
        }
        break;
      }
  
      default: {
        if( sqlite3_get_autocommit(p->db) ){
          if( (p->eRestoreState & 2) ){
            sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 1, 0);
          }
          if( (p->eRestoreState & 4) ){
            sqlite3_db_config(p->db, SQLITE_DBCONFIG_DQS_DDL, 0, 0);
          }
          p->eRestoreState = 7;
        }
        break;
      }
    }
  }

  return rc;
}

/*
** Run a single line of SQL.  Return the number of errors.
*/
static int runOneSqlLine(
  ShellState *p,            /* Execution context */
  char *zSql,               /* SQL to be run */
  const char *zFilename,    /* Source file of the sql */
  int startline             /* linenumber */
){
  int rc;
  char *zErrMsg = 0;

  open_db(p, 0);
  if( ShellHasFlag(p,SHFLG_Backslash) ) resolve_backslashes(zSql);
  if( p->flgProgress & SHELL_PROGRESS_RESET ) p->nProgress = 0;
  BEGIN_TIMER(p);
  rc = shell_exec(p, zSql, &zErrMsg);
  END_TIMER(p);
  if( rc || zErrMsg ){
    char zPrefix[100];
    const char *zErrorTail;
    const char *zErrorType;
    if( zErrMsg==0 ){
      zErrorType = "Error";
      zErrorTail = sqlite3_errmsg(p->db);
    }else if( cli_strncmp(zErrMsg, "in prepare, ",12)==0 ){
      zErrorType = "Parse error";
      zErrorTail = &zErrMsg[12];
    }else if( cli_strncmp(zErrMsg, "stepping, ", 10)==0 ){
      zErrorType = "Runtime error";
      zErrorTail = &zErrMsg[10];
    }else{
      zErrorType = "Error";
      zErrorTail = zErrMsg;
    }
    if( zFilename || !stdin_is_interactive ){
      if( cli_strcmp(zFilename,"cmdline")==0 ){
        sqlite3_snprintf(sizeof(zPrefix), zPrefix,
                  "%s in %r command line argument:", zErrorType, startline);
      }else if( cli_strcmp(zFilename,"<stdin>")==0 ){
        sqlite3_snprintf(sizeof(zPrefix), zPrefix,
                  "%s near line %d:", zErrorType, startline);
      }else{
        sqlite3_snprintf(sizeof(zPrefix), zPrefix,
                  "%s near line %d of %s:", zErrorType, startline, zFilename);
      }
    }else{
      sqlite3_snprintf(sizeof(zPrefix), zPrefix, "%s:", zErrorType);
    }
    cli_printf(stderr,"%s %s\n", zPrefix, zErrorTail);
    sqlite3_free(zErrMsg);
    zErrMsg = 0;
    return 1;
  }else if( ShellHasFlag(p, SHFLG_CountChanges) ){
    char zLineBuf[2000];
    sqlite3_snprintf(sizeof(zLineBuf), zLineBuf,
            "changes: %lld   total_changes: %lld",
            sqlite3_changes64(p->db), sqlite3_total_changes64(p->db));
    cli_printf(p->out, "%s\n", zLineBuf);
  }

  if( doAutoDetectRestore(p, zSql) ) return 1;
  return 0;
}

static void echo_group_input(ShellState *p, const char *zDo){
  if( p->mode.mFlags & MFLG_ECHO ){
    cli_printf(p->out, "%s\n", zDo);
    fflush(p->out);
  }
}

#ifdef SQLITE_SHELL_FIDDLE
/*
** Alternate one_input_line() impl for wasm mode. This is not in the primary
** impl because we need the global shellState and cannot access it from that
** function without moving lots of code around (creating a larger/messier diff).
*/
static char *one_input_line(ShellState *p, char *zPrior, int isContinuation){
  /* Parse the next line from shellState.wasm.zInput. */
  const char *zBegin = shellState.wasm.zPos;
  const char *z = zBegin;
  char *zLine = 0;
  i64 nZ = 0;
  FILE *in = p->in;

  UNUSED_PARAMETER(in);
  UNUSED_PARAMETER(isContinuation);
  if(!z || !*z){
    return 0;
  }
  while(*z && IsSpace(*z)) ++z;
  zBegin = z;
  for(; *z && '\n'!=*z; ++nZ, ++z){}
  if(nZ>0 && '\r'==zBegin[nZ-1]){
    --nZ;
  }
  shellState.wasm.zPos = z;
  zLine = realloc(zPrior, nZ+1);
  shell_check_oom(zLine);
  memcpy(zLine, zBegin, nZ);
  zLine[nZ] = 0;
  return zLine;
}
#endif /* SQLITE_SHELL_FIDDLE */

/*
** Read input from *in and process it.  If *in==0 then input
** is interactive - the user is typing it it.  Otherwise, input
** is coming from a file or device.  A prompt is issued and history
** is saved only if input is interactive.  An interrupt signal will
** cause this routine to exit immediately, unless input is interactive.
**
** Return the number of errors.
*/
static int process_input(ShellState *p, const char *zSrc){
  char *zLine = 0;          /* A single input line */
  char *zSql = 0;           /* Accumulated SQL text */
  i64 nLine;                /* Length of current line */
  i64 nSql = 0;             /* Bytes of zSql[] used */
  i64 nAlloc = 0;           /* Allocated zSql[] space */
  int rc;                   /* Error code */
  int errCnt = 0;           /* Number of errors seen */
  i64 startline = 0;        /* Line number for start of current input */
  QuickScanState qss = QSS_Start; /* Accumulated line status (so far) */
  const char *saved_zInFile;      /* Prior value of p->zInFile */
  i64 saved_lineno;               /* Prior value of p->lineno */

  if( p->inputNesting==MAX_INPUT_NESTING ){
    /* This will be more informative in a later version. */
    cli_printf(stderr,"%s: Input nesting limit (%d) reached at line %lld."
          " Check recursion.\n", zSrc, MAX_INPUT_NESTING, p->lineno);
    return 1;
  }
  ++p->inputNesting;
  saved_zInFile = p->zInFile;
  p->zInFile = zSrc;
  saved_lineno = p->lineno;
  p->lineno = 0;
  CONTINUE_PROMPT_RESET;
  while( errCnt==0 || !bail_on_error || (p->in==0 && stdin_is_interactive) ){
    fflush(p->out);
    zLine = one_input_line(p, zLine, nSql>0);
    if( zLine==0 ){
      /* End of input */
      if( p->in==0 && stdin_is_interactive ) cli_puts("\n", p->out);
      break;
    }
    if( seenInterrupt ){
      if( p->in!=0 ) break;
      seenInterrupt = 0;
    }
    p->lineno++;
    if( QSS_INPLAIN(qss)
        && line_is_command_terminator(zLine)
        && line_is_complete(zSql, nSql) ){
      memcpy(zLine,";",2);
    }
    qss = quickscan(zLine, qss, CONTINUE_PROMPT_PSTATE);
    if( QSS_PLAINWHITE(qss) && nSql==0 ){
      /* Just swallow single-line whitespace */
      echo_group_input(p, zLine);
      qss = QSS_Start;
      continue;
    }
    if( zLine && (zLine[0]=='.' || zLine[0]=='#') && nSql==0 ){
      CONTINUE_PROMPT_RESET;
      echo_group_input(p, zLine);
      if( zLine[0]=='.' ){
        rc = do_meta_command(zLine, p);
        if( rc==2 ){ /* exit requested */
          break;
        }else if( rc ){
          errCnt++;
        }
      }
      qss = QSS_Start;
      continue;
    }
    /* No single-line dispositions remain; accumulate line(s). */
    nLine = strlen(zLine);
    if( nSql+nLine+2>=nAlloc ){
      /* Grow buffer by half-again increments when big. */
      nAlloc = nSql+(nSql>>1)+nLine+100;
      zSql = realloc(zSql, nAlloc);
      shell_check_oom(zSql);
    }
    if( nSql==0 ){
      i64 i;
      for(i=0; zLine[i] && IsSpace(zLine[i]); i++){}
      assert( nAlloc>0 && zSql!=0 );
      memcpy(zSql, zLine+i, nLine+1-i);
      startline = p->lineno;
      nSql = nLine-i;
    }else{
      zSql[nSql++] = '\n';
      memcpy(zSql+nSql, zLine, nLine+1);
      nSql += nLine;
    }
    if( nSql>0x7fff0000 ){
      char zSize[100];
      sqlite3_snprintf(sizeof(zSize),zSize,"%,lld",nSql);
      cli_printf(stderr, "%s:%lld: Input SQL is too big: %s bytes\n",
                      zSrc, startline, zSize);
      nSql = 0;
      errCnt++;
      break;
    }else if( nSql && QSS_SEMITERM(qss) && sqlite3_complete(zSql) ){
      echo_group_input(p, zSql);
      errCnt += runOneSqlLine(p, zSql, p->zInFile, startline);
      CONTINUE_PROMPT_RESET;
      nSql = 0;
      if( p->nPopOutput ){
        output_reset(p);
        p->nPopOutput = 0;
      }else{
        clearTempFile(p);
      }
      if( p->nPopMode ){
        modePop(p);
        p->nPopMode = 0;
      }
      p->bSafeMode = p->bSafeModePersist;
      qss = QSS_Start;
    }else if( nSql && QSS_PLAINWHITE(qss) ){
      echo_group_input(p, zSql);
      nSql = 0;
      qss = QSS_Start;
    }
  }
  if( nSql ){
    /* This may be incomplete. Let the SQL parser deal with that. */
    echo_group_input(p, zSql);
    errCnt += runOneSqlLine(p, zSql, p->zInFile, startline);
    CONTINUE_PROMPT_RESET;
  }
  free(zSql);
  free(zLine);
  --p->inputNesting;
  p->zInFile = saved_zInFile;
  p->lineno = saved_lineno;
  return errCnt>0;
}

/*
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.
*/
static char *find_home_dir(int clearFlag){
  static char *home_dir = NULL;
  if( clearFlag ){
    free(home_dir);
    home_dir = 0;
    return 0;
  }
  if( home_dir ) return home_dir;

#if !defined(_WIN32) && !defined(WIN32) && !defined(_WIN32_WCE) \
     && !defined(__RTP__) && !defined(_WRS_KERNEL) && !defined(SQLITE_WASI)
  {
    struct passwd *pwent;
    uid_t uid = getuid();
    if( (pwent=getpwuid(uid)) != NULL) {
      home_dir = pwent->pw_dir;
    }
  }
#endif

#if defined(_WIN32_WCE)
  /* Windows CE (arm-wince-mingw32ce-gcc) does not provide getenv()
   */
  home_dir = "/";
#else

#if defined(_WIN32) || defined(WIN32)
  if (!home_dir) {
    home_dir = getenv("USERPROFILE");
  }
#endif

  if (!home_dir) {
    home_dir = getenv("HOME");
  }

#if defined(_WIN32) || defined(WIN32)
  if (!home_dir) {
    char *zDrive, *zPath;
    int n;
    zDrive = getenv("HOMEDRIVE");
    zPath = getenv("HOMEPATH");
    if( zDrive && zPath ){
      n = strlen30(zDrive) + strlen30(zPath) + 1;
      home_dir = malloc( n );
      if( home_dir==0 ) return 0;
      sqlite3_snprintf(n, home_dir, "%s%s", zDrive, zPath);
      return home_dir;
    }
    home_dir = "c:\\";
  }
#endif

#endif /* !_WIN32_WCE */

  if( home_dir ){
    i64 n = strlen(home_dir) + 1;
    char *z = malloc( n );
    if( z ) memcpy(z, home_dir, n);
    home_dir = z;
  }

  return home_dir;
}

/*
** On non-Windows platforms, look for:
**
** - ${zEnvVar}/${zBaseName}
** - ${HOME}/${zSubdir}/${zBaseName}
**
** $zEnvVar is intended to be the name of an XDG_... environment
** variable, e.g. XDG_CONFIG_HOME or XDG_STATE_HOME.  If zEnvVar is
** NULL or getenv(zEnvVar) is NULL then fall back to the second
** option. If the selected option is not found in the filesystem,
** return 0.
**
** zSubdir may be NULL or empty, in which case ${HOME}/${zBaseName}
** becomes the fallback.
**
** Both zSubdir and zBaseName may contain subdirectory parts. zSubdir
** will conventionally be ".config" or ".local/state", which, not
** coincidentally, is the typical subdir of the corresponding XDG_...
** var with the XDG var's $HOME prefix.
**
** The returned string is obtained from sqlite3_malloc() and should be
** sqlite3_free()'d by the caller.
*/
static char *find_xdg_file(const char *zEnvVar, const char *zSubdir,
                           const char *zBaseName){
#if defined(_WIN32) || defined(WIN32) || defined(_WIN32_WCE) \
     || defined(__RTP__) || defined(_WRS_KERNEL)
  return 0;
#else
  char *zConfigFile = 0;
  const char *zXdgDir;

  zXdgDir = zEnvVar ? getenv(zEnvVar) : 0;
  if( zXdgDir ){
    zConfigFile = sqlite3_mprintf("%s/%s", zXdgDir, zBaseName);
  }else{
    const char * zHome = find_home_dir(0);
    if( zHome==0 ) return 0;
    zConfigFile = (zSubdir && *zSubdir)
      ? sqlite3_mprintf("%s/%s/%s", zHome, zSubdir, zBaseName)
      : sqlite3_mprintf("%s/%s", zHome, zBaseName);
  }
  shell_check_oom(zConfigFile);
  if( access(zConfigFile,0)!=0 ){
    sqlite3_free(zConfigFile);
    zConfigFile = 0;
  }
  return zConfigFile;
#endif
}

/*
** Read input from the file sqliterc_override.  If that parameter is
** NULL, take it from find_xdg_file(), if found, or fall back to
** ~/.sqliterc.
**
** Failure to read the config is only considered a failure if
** sqliterc_override is not NULL, in which case this function may emit
** a warning or, if ::bail_on_error is true, fail fatally if the file
** named by sqliterc_override is not found.
*/
static void process_sqliterc(
  ShellState *p,                  /* Configuration data */
  const char *sqliterc_override   /* Name of config file. NULL to use default */
){
  char *home_dir = NULL;
  char *sqliterc = (char*)sqliterc_override;
  FILE *inSaved = p->in;
  i64 savedLineno = p->lineno;

  if( sqliterc == NULL ){
    sqliterc = find_xdg_file("XDG_CONFIG_HOME",
                             ".config",
                             "sqlite3/sqliterc");
  }
  if( sqliterc == NULL ){
    home_dir = find_home_dir(0);
    if( home_dir==0 ){
      eputz("-- warning: cannot find home directory;"
            " cannot read ~/.sqliterc\n");
      return;
    }
    sqliterc = sqlite3_mprintf("%s/.sqliterc",home_dir);
    shell_check_oom(sqliterc);
  }
  p->in = sqliterc ? sqlite3_fopen(sqliterc,"rb") : 0;
  if( p->in ){
    if( stdin_is_interactive ){
      cli_printf(stderr,"-- Loading resources from %s\n", sqliterc);
    }
    if( process_input(p, sqliterc) && bail_on_error ) cli_exit(1);
    fclose(p->in);
  }else if( sqliterc_override!=0 ){
    cli_printf(stderr,"cannot open: \"%s\"\n", sqliterc);
    if( bail_on_error ) cli_exit(1);
  }
  p->in = inSaved;
  p->lineno = savedLineno;
  if( sqliterc != sqliterc_override ){
    sqlite3_free(sqliterc);
  }
}

/*
** Show available command line options
*/
static const char zOptions[] =
  "   --                   treat no subsequent arguments as options\n"
#if defined(SQLITE_HAVE_ZLIB) && !defined(SQLITE_OMIT_VIRTUALTABLE)
  "   -A ARGS...           run \".archive ARGS\" and exit\n"
#endif
  "   -append              append the database to the end of the file\n"
  "   -ascii               set output mode to 'ascii'\n"
  "   -bail                stop after hitting an error\n"
  "   -batch               force batch I/O\n"
  "   -box                 set output mode to 'box'\n"
  "   -cmd COMMAND         run \"COMMAND\" before reading stdin\n"
  "   -column              set output mode to 'column'\n"
  "   -csv                 set output mode to 'csv'\n"
#if !defined(SQLITE_OMIT_DESERIALIZE)
  "   -deserialize         open the database using sqlite3_deserialize()\n"
#endif
  "   -echo                print inputs before execution\n"
  "   -escape T            ctrl-char escape; T is one of: symbol, ascii, off\n"
  "   -init FILENAME       read/process named file\n"
  "   -[no]header          turn headers on or off\n"
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
  "   -heap SIZE           Size of heap for memsys3 or memsys5\n"
#endif
  "   -help                show this message\n"
  "   -html                set output mode to HTML\n"
  "   -ifexists            only open if database already exists\n"
  "   -interactive         force interactive I/O\n"
  "   -json                set output mode to 'json'\n"
  "   -line                set output mode to 'line'\n"
  "   -list                set output mode to 'list'\n"
  "   -lookaside SIZE N    use N entries of SZ bytes for lookaside memory\n"
  "   -markdown            set output mode to 'markdown'\n"
#if !defined(SQLITE_OMIT_DESERIALIZE)
  "   -maxsize N           maximum size for a --deserialize database\n"
#endif
  "   -memtrace            trace all memory allocations and deallocations\n"
  "   -mmap N              default mmap size set to N\n"
#ifdef SQLITE_ENABLE_MULTIPLEX
  "   -multiplex           enable the multiplexor VFS\n"
#endif
  "   -newline SEP         set output row separator. Default: '\\n'\n"
  "   -nofollow            refuse to open symbolic links to database files\n"
  "   -noinit              Do not read the ~/.sqliterc file at startup\n"
  "   -nonce STRING        set the safe-mode escape nonce\n"
  "   -no-rowid-in-view    Disable rowid-in-view using sqlite3_config()\n"
  "   -nullvalue TEXT      set text string for NULL values. Default ''\n"
  "   -pagecache SIZE N    use N slots of SZ bytes each for page cache memory\n"
  "   -pcachetrace         trace all page cache operations\n"
  "   -quote               set output mode to 'quote'\n"
  "   -readonly            open the database read-only\n"
  "   -safe                enable safe-mode\n"
  "   -screenwidth N       use N as the default screenwidth \n"
  "   -separator SEP       set output column separator. Default: '|'\n"
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
  "   -sorterref SIZE      sorter references threshold size\n"
#endif
  "   -stats               print memory stats before each finalize\n"
  "   -table               set output mode to 'table'\n"
  "   -tabs                set output mode to 'tabs'\n"
  "   -unsafe-testing      allow unsafe commands and modes for testing\n"
  "   -version             show SQLite version\n"
  "   -vfs NAME            use NAME as the default VFS\n"
  "   -vfstrace            enable tracing of all VFS calls\n"
#ifdef SQLITE_HAVE_ZLIB
  "   -zip                 open the file as a ZIP Archive\n"
#endif
;
static void usage(int showDetail){
  cli_printf(stderr,"Usage: %s [OPTIONS] [FILENAME [SQL...]]\n"
       "FILENAME is the name of an SQLite database. A new database is created\n"
       "if the file does not previously exist. Defaults to :memory:.\n", Argv0);
  if( showDetail ){
    cli_printf(stderr,"OPTIONS include:\n%s", zOptions);
  }else{
    eputz("Use the -help option for additional information\n");
  }
  exit(0);
}

/*
** Internal check:  Verify that the SQLite is uninitialized.  Print a
** error message if it is initialized.
*/
static void verify_uninitialized(void){
  if( sqlite3_config(-1)==SQLITE_MISUSE ){
    sputz(stdout, "WARNING: attempt to configure SQLite after"
          " initialization.\n");
  }
}

/*
** Initialize the state information in data
*/
static void main_init(ShellState *p) {
  memset(p, 0, sizeof(*p));
  p->pAuxDb = &p->aAuxDb[0];
  p->shellFlgs = SHFLG_Lookaside;
  sqlite3_config(SQLITE_CONFIG_LOG, shellLog, p);
#if !defined(SQLITE_SHELL_FIDDLE)
  verify_uninitialized();
#endif
  sqlite3_config(SQLITE_CONFIG_URI, 1);
  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);
  sqlite3_snprintf(sizeof(mainPrompt), mainPrompt,"sqlite> ");
  sqlite3_snprintf(sizeof(continuePrompt), continuePrompt,"   ...> ");
}

/*
** Output text to the console in a font that attracts extra attention.
*/
#if defined(_WIN32) || defined(WIN32)
static void printBold(const char *zText){
  HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
  CONSOLE_SCREEN_BUFFER_INFO defaultScreenInfo;
  GetConsoleScreenBufferInfo(out, &defaultScreenInfo);
  SetConsoleTextAttribute(out,
         FOREGROUND_RED|FOREGROUND_INTENSITY
  );
  sputz(stdout, zText);
  SetConsoleTextAttribute(out, defaultScreenInfo.wAttributes);
}
#else
static void printBold(const char *zText){
  cli_printf(stdout, "\033[1m%s\033[0m", zText);
}
#endif

/*
** Get the argument to an --option.  Throw an error and die if no argument
** is available.
*/
static char *cmdline_option_value(int argc, char **argv, int i){
  if( i==argc ){
    cli_printf(stderr,
            "%s: Error: missing argument to %s\n", argv[0], argv[argc-1]);
    cli_exit(1);
  }
  return argv[i];
}

static void sayAbnormalExit(void){
  if( seenInterrupt ) eputz("Program interrupted.\n");
}

/* Routine to output from vfstrace
*/
static int vfstraceOut(const char *z, void *pArg){
  ShellState *p = (ShellState*)pArg;
  cli_puts(z, p->out);
  fflush(p->out);
  return 1;
}

#if defined(SQLITE_DEBUG) && !defined(SQLITE_SHELL_FIDDLE)
/* Ensure that sqlite3_reset_auto_extension() clears auto-extension
** memory. https://sqlite.org/forum/forumpost/310cb231b07c80d1.
** Testing this: if we (inadvertently) remove the
** sqlite3_reset_auto_extension() call from main(), most shell tests
** will fail because of a leak message in their output. */
static int auto_ext_leak_tester(
  sqlite3 *db,
  char **pzErrMsg,
  const struct sqlite3_api_routines *pThunk
){
  (void)db; (void)pzErrMsg; (void)pThunk;
  return SQLITE_OK;
}
#endif

/* Alternative name to the entry point for Fiddle */
#ifdef SQLITE_SHELL_FIDDLE
#  define main fiddle_main
#endif

/* Use the wmain() entry point on Windows.  Translate arguments to
** UTF8, then invoke the traditional main() entry point which is
** renamed using a #define to utf8_main() .
*/
#if defined(_WIN32) && !defined(__MINGW32__) && !defined(main)
#  define main utf8_main                 /* Rename entry point to utf_main() */
int SQLITE_CDECL utf8_main(int,char**);  /* Forward declaration */  
int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
  int rc, i;
  char **argv = malloc( sizeof(char*) * (argc+1) );
  char **orig = argv;
  if( argv==0 ){
    fprintf(stderr, "malloc failed\n");
    exit(1);
  }
  for(i=0; i<argc; i++){
    int nByte = WideCharToMultiByte(CP_UTF8, 0, wargv[i], -1, 0, 0, 0, 0);
    if( nByte==0 ){
      argv[i] = 0;
    }else{
      argv[i] = malloc( nByte );
      if( argv[i]==0 ){
        fprintf(stderr, "malloc failed\n");
        exit(1);
      }
      nByte = WideCharToMultiByte(CP_UTF8, 0, wargv[i], -1, argv[i],nByte,0,0);
      if( nByte==0 ){
        free(argv[i]);
        argv[i] = 0;
      }
    }
  }
  argv[argc] = 0;
  rc = utf8_main(argc, argv);
  for(i=0; i<argc; i++) free(orig[i]);
  free(argv);
  return rc;
}
#endif /* WIN32 */

/*
** This is the main entry point for the process.  Everything starts here.
**
** The "main" identifier may have been #defined to something else:
**
**     utf8_main            On Windows
**     fiddle_main          In Fiddle
**     sqlite3_shell        Other projects that use shell.c as a subroutine
*/
int SQLITE_CDECL main(int argc, char **argv){
#ifdef SQLITE_DEBUG
  sqlite3_int64 mem_main_enter = 0;
#endif
#ifdef SQLITE_SHELL_FIDDLE
#  define data shellState
#else
  ShellState data;
#endif
  const char *zInitFile = 0;
  int i;
  int rc = 0;
  int warnInmemoryDb = 0;
  int readStdin = 1;
  int noInit = 0;                 /* Do not read ~/.sqliterc if true */
  int nCmd = 0;
  int nOptsEnd = argc;
  int bEnableVfstrace = 0;
  char **azCmd = 0;
  int *aiCmd = 0;
  const char *zVfs = 0;           /* Value of -vfs command-line option */
  setvbuf(stderr, 0, _IONBF, 0); /* Make sure stderr is unbuffered */

#ifdef SQLITE_SHELL_FIDDLE
  stdin_is_interactive = 0;
  stdout_is_console = 1;
  data.wasm.zDefaultDbName = "/fiddle.sqlite3";
#else
  stdin_is_interactive = isatty(0);
  stdout_is_console = isatty(1);
#endif
  atexit(sayAbnormalExit);
#ifdef SQLITE_DEBUG
  mem_main_enter = sqlite3_memory_used();
#endif
#if !defined(_WIN32_WCE)
  if( getenv("SQLITE_DEBUG_BREAK") ){
    if( isatty(0) && isatty(2) ){
      char zLine[100];
      cli_printf(stderr,
            "attach debugger to process %d and press ENTER to continue...",
            GETPID());
      if( sqlite3_fgets(zLine, sizeof(zLine), stdin)!=0
       && cli_strcmp(zLine,"stop")==0
      ){
        exit(1);
      }
    }else{
#if defined(_WIN32) || defined(WIN32)
      DebugBreak();
#elif defined(SIGTRAP)
      raise(SIGTRAP);
#endif
    }
  }
#endif
  /* Register a valid signal handler early, before much else is done. */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);
#elif (defined(_WIN32) || defined(WIN32)) && !defined(_WIN32_WCE)
  if( !SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE) ){
    eputz("No ^C handler.\n");
  }
#endif

#if USE_SYSTEM_SQLITE+0!=1
  if( cli_strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,60)!=0 ){
    cli_printf(stderr,
          "SQLite header and source version mismatch\n%s\n%s\n",
          sqlite3_sourceid(), SQLITE_SOURCE_ID);
    exit(1);
  }
#endif
  main_init(&data);

  assert( argc>=1 && argv && argv[0] );
  Argv0 = argv[0];

#ifdef SQLITE_SHELL_DBNAME_PROC
  {
    /* If the SQLITE_SHELL_DBNAME_PROC macro is defined, then it is the name
    ** of a C-function that will provide the name of the database file.  Use
    ** this compile-time option to embed this shell program in larger
    ** applications. */
    extern void SQLITE_SHELL_DBNAME_PROC(const char**);
    SQLITE_SHELL_DBNAME_PROC(&data.pAuxDb->zDbFilename);
    warnInmemoryDb = 0;
  }
#endif

  /* Do an initial pass through the command-line arguments to locate
  ** the name of the database file, the name of the initialization file,
  ** the size of the alternative malloc heap, options affecting commands
  ** or SQL run from the command line, and the first command to execute.
  */
#ifndef SQLITE_SHELL_FIDDLE
  verify_uninitialized();
#endif
  for(i=1; i<argc; i++){
    char *z;
    z = argv[i];
    if( z[0]!='-' || i>nOptsEnd ){
      if( data.aAuxDb->zDbFilename==0 && !isScriptFile(z,1) ){
        data.aAuxDb->zDbFilename = z;
      }else{
        /* Excess arguments are interpreted as SQL (or dot-commands) and
        ** mean that nothing is read from stdin */
        readStdin = 0;
        stdin_is_interactive = 0;
        nCmd++;
        azCmd = realloc(azCmd, sizeof(azCmd[0])*nCmd);
        shell_check_oom(azCmd);
        aiCmd = realloc(aiCmd, sizeof(aiCmd[0])*nCmd);
        shell_check_oom(azCmd);
        azCmd[nCmd-1] = z;
        aiCmd[nCmd-1] = i;
      }
      continue;
    }
    if( z[1]=='-' ) z++;
    if( cli_strcmp(z, "-")==0 ){
      nOptsEnd = i;
      continue;
    }else if( cli_strcmp(z,"-separator")==0
     || cli_strcmp(z,"-nullvalue")==0
     || cli_strcmp(z,"-newline")==0
     || cli_strcmp(z,"-cmd")==0
    ){
      (void)cmdline_option_value(argc, argv, ++i);
    }else if( cli_strcmp(z,"-init")==0 ){
      zInitFile = cmdline_option_value(argc, argv, ++i);
    }else if( cli_strcmp(z,"-interactive")==0 ){
    }else if( cli_strcmp(z,"-batch")==0 ){
      /* Need to check for batch mode here to so we can avoid printing
      ** informational messages (like from process_sqliterc) before
      ** we do the actual processing of arguments later in a second pass.
      */
      stdin_is_interactive = 0;
      stdout_is_console = 0;
      modeChange(&data, MODE_BATCH);
    }else if( cli_strcmp(z,"-screenwidth")==0 ){
      int n = atoi(cmdline_option_value(argc, argv, ++i));
      if( n<2 ){
        sqlite3_fprintf(stderr,"minimum --screenwidth is 2\n");
        exit(1);
      }
      stdout_tty_width = n;
    }else if( cli_strcmp(z,"-utf8")==0 ){
    }else if( cli_strcmp(z,"-no-utf8")==0 ){
    }else if( cli_strcmp(z,"-no-rowid-in-view")==0 ){
      int val = 0;
      sqlite3_config(SQLITE_CONFIG_ROWID_IN_VIEW, &val);
      assert( val==0 );
    }else if( cli_strcmp(z,"-heap")==0 ){
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
      const char *zSize;
      sqlite3_int64 szHeap;

      zSize = cmdline_option_value(argc, argv, ++i);
      szHeap = integerValue(zSize);
      if( szHeap>0x7fff0000 ) szHeap = 0x7fff0000;
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_HEAP, malloc((int)szHeap), (int)szHeap, 64);
#else
      (void)cmdline_option_value(argc, argv, ++i);
#endif
    }else if( cli_strcmp(z,"-pagecache")==0 ){
      sqlite3_int64 n, sz;
      sz = integerValue(cmdline_option_value(argc,argv,++i));
      if( sz>65536 ) sz = 65536;
      if( sz<0 ) sz = 0;
      n = integerValue(cmdline_option_value(argc,argv,++i));
      if( sz>0 && n>0 && 0xffffffffffffLL/sz<n ){
        n = 0xffffffffffffLL/sz;
      }
      if( sz>0 && (sz & (sz-1))==0 ){
        /* If SIZE is a power of two, round it up by the PCACHE_HDRSZ */
        int szHdr = 0;
        sqlite3_config(SQLITE_CONFIG_PCACHE_HDRSZ, &szHdr);
        sz += szHdr;
        cli_printf(stdout, "Page cache size increased to %d to accommodate"
                        " the %d-byte headers\n", (int)sz, szHdr);
      }
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_PAGECACHE,
                    (n>0 && sz>0) ? malloc(n*sz) : 0, sz, n);
      data.shellFlgs |= SHFLG_Pagecache;
    }else if( cli_strcmp(z,"-lookaside")==0 ){
      int n, sz;
      sz = (int)integerValue(cmdline_option_value(argc,argv,++i));
      if( sz<0 ) sz = 0;
      n = (int)integerValue(cmdline_option_value(argc,argv,++i));
      if( n<0 ) n = 0;
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_LOOKASIDE, sz, n);
      if( (i64)sz*(i64)n==0 ) data.shellFlgs &= ~SHFLG_Lookaside;
    }else if( cli_strcmp(z,"-threadsafe")==0 ){
      int n;
      n = (int)integerValue(cmdline_option_value(argc,argv,++i));
      verify_uninitialized();
      switch( n ){
         case 0:  sqlite3_config(SQLITE_CONFIG_SINGLETHREAD);  break;
         case 2:  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);   break;
         default: sqlite3_config(SQLITE_CONFIG_SERIALIZED);    break;
      }
    }else if( cli_strcmp(z,"-vfstrace")==0 ){
      bEnableVfstrace = 1;
#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( cli_strcmp(z,"-multiplex")==0 ){
      extern int sqlite3_multiplex_initialize(const char*,int);
      sqlite3_multiplex_initialize(0, 1);
#endif
    }else if( cli_strcmp(z,"-mmap")==0 ){
      sqlite3_int64 sz = integerValue(cmdline_option_value(argc,argv,++i));
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_MMAP_SIZE, sz, sz);
#if defined(SQLITE_ENABLE_SORTER_REFERENCES)
    }else if( cli_strcmp(z,"-sorterref")==0 ){
      sqlite3_int64 sz = integerValue(cmdline_option_value(argc,argv,++i));
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_SORTERREF_SIZE, (int)sz);
#endif
    }else if( cli_strcmp(z,"-vfs")==0 ){
      zVfs = cmdline_option_value(argc, argv, ++i);
#ifdef SQLITE_HAVE_ZLIB
    }else if( cli_strcmp(z,"-zip")==0 ){
      data.openMode = SHELL_OPEN_ZIPFILE;
#endif
    }else if( cli_strcmp(z,"-append")==0 ){
      data.openMode = SHELL_OPEN_APPENDVFS;
#ifndef SQLITE_OMIT_DESERIALIZE
    }else if( cli_strcmp(z,"-deserialize")==0 ){
      data.openMode = SHELL_OPEN_DESERIALIZE;
    }else if( cli_strcmp(z,"-maxsize")==0 && i+1<argc ){
      data.szMax = integerValue(argv[++i]);
#endif
    }else if( cli_strcmp(z,"-readonly")==0 ){
      data.openFlags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
      data.openFlags |= SQLITE_OPEN_READONLY;
    }else if( cli_strcmp(z,"-nofollow")==0 ){
      data.openFlags |= SQLITE_OPEN_NOFOLLOW;
    }else if( cli_strcmp(z,"-noinit")==0 ){
      noInit = 1;
    }else if( cli_strcmp(z,"-exclusive")==0 ){  /* UNDOCUMENTED */
      data.openFlags |= SQLITE_OPEN_EXCLUSIVE;
    }else if( cli_strcmp(z,"-ifexists")==0 ){
      data.openFlags &= ~(SQLITE_OPEN_CREATE);
      if( data.openFlags==0 ) data.openFlags = SQLITE_OPEN_READWRITE;
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
    }else if( cli_strncmp(z, "-A",2)==0 ){
      /* All remaining command-line arguments are passed to the ".archive"
      ** command, so ignore them */
      break;
#endif
    }else if( cli_strcmp(z, "-memtrace")==0 ){
      sqlite3MemTraceActivate(stderr);
    }else if( cli_strcmp(z, "-pcachetrace")==0 ){
      sqlite3PcacheTraceActivate(stderr);
    }else if( cli_strcmp(z,"-bail")==0 ){
      bail_on_error = 1;
    }else if( cli_strcmp(z,"-nonce")==0 ){
      free(data.zNonce);
      data.zNonce = strdup(cmdline_option_value(argc, argv, ++i));
    }else if( cli_strcmp(z,"-unsafe-testing")==0 ){
      ShellSetFlag(&data,SHFLG_TestingMode);
    }else if( cli_strcmp(z,"-safe")==0 ){
      /* no-op - catch this on the second pass */
    }else if( cli_strcmp(z,"-escape")==0 && i+1<argc ){
      /* skip over the argument */
      i++;
    }else if( cli_strcmp(z,"-test-argv")==0 ){
      /* Undocumented test option.  Print the values in argv[] and exit.
      ** Use this to verify that any translation of the argv[], for example
      ** on Windows that receives wargv[] from the OS and must convert
      ** to UTF8 prior to calling this routine. */
      int kk;
      for(kk=0; kk<argc; kk++){
        sqlite3_fprintf(stdout,"argv[%d] = \"%s\"\n", kk, argv[kk]);
      }
      return 0;
    }
  }
#ifndef SQLITE_SHELL_FIDDLE
  if( !bEnableVfstrace ) verify_uninitialized();
#endif


#ifdef SQLITE_SHELL_INIT_PROC
  {
    /* If the SQLITE_SHELL_INIT_PROC macro is defined, then it is the name
    ** of a C-function that will perform initialization actions on SQLite that
    ** occur just before or after sqlite3_initialize(). Use this compile-time
    ** option to embed this shell program in larger applications. */
    extern void SQLITE_SHELL_INIT_PROC(void);
    SQLITE_SHELL_INIT_PROC();
  }
#else
  /* All the sqlite3_config() calls have now been made. So it is safe
  ** to call sqlite3_initialize() and process any command line -vfs option. */
  sqlite3_initialize();
#endif

  if( zVfs ){
    sqlite3_vfs *pVfs = sqlite3_vfs_find(zVfs);
    if( pVfs ){
      sqlite3_vfs_register(pVfs, 1);
    }
#if !defined(SQLITE_OMIT_LOAD_EXTENSION)
    else if( access(zVfs,0)==0 ){
      /* If the VFS name is not the name of an existing VFS, but it is
      ** the name of a file, then try to load that file as an extension.
      ** Presumably the extension implements the desired VFS. */
      sqlite3 *db = 0;
      char *zErr = 0;
      sqlite3_open(":memory:", &db);
      sqlite3_enable_load_extension(db, 1);
      rc = sqlite3_load_extension(db, zVfs, 0, &zErr);
      sqlite3_close(db);
      if( (rc&0xff)!=SQLITE_OK ){
        cli_printf(stderr, "could not load extension VFS \"%s\": %s\n",
                   zVfs, zErr);
        exit(1);
      }
    }
#endif
    else{
      cli_printf(stderr,"no such VFS: \"%s\"\n", zVfs);
      exit(1);
    }
  }

  if( data.pAuxDb->zDbFilename==0 ){
#ifndef SQLITE_OMIT_MEMORYDB
    data.pAuxDb->zDbFilename = ":memory:";
    warnInmemoryDb = argc==1;
#else
    cli_printf(stderr,
                    "%s: Error: no database filename specified\n", Argv0);
    rc = 1;
    goto shell_main_exit;
#endif
  }
  data.out = stdout;
  if( bEnableVfstrace ){
    vfstrace_register("trace",0,vfstraceOut, &data, 1);
  }
#ifndef SQLITE_SHELL_FIDDLE
  sqlite3_appendvfs_init(0,0,0);
#ifdef SQLITE_DEBUG
  sqlite3_auto_extension( (void (*)())auto_ext_leak_tester );
#endif
#endif
  modeDefault(&data);

  /* Go ahead and open the database file if it already exists.  If the
  ** file does not exist, delay opening it.  This prevents empty database
  ** files from being created if a user mistypes the database name argument
  ** to the sqlite command-line tool.
  */
  if( access(data.pAuxDb->zDbFilename, 0)==0 ){
    open_db(&data, 0);
  }

  /* Process the initialization file if there is one.  If no -init option
  ** is given on the command line, look for a file named ~/.sqliterc and
  ** try to process it.
  */
  if( !noInit ) process_sqliterc(&data,zInitFile);

  /* Make a second pass through the command-line arguments and set
  ** options.  This second pass is delayed until after the initialization
  ** file is processed so that the command-line arguments will override
  ** settings in the initialization file.
  */
  for(i=1; i<argc; i++){
    char *z = argv[i];
    if( z[0]!='-' || i>=nOptsEnd ) continue;
    if( z[1]=='-' ){ z++; }
    if( cli_strcmp(z,"-init")==0 ){
      i++;
    }else if( cli_strcmp(z,"-html")==0 ){
      modeChange(&data, MODE_Html);
    }else if( cli_strcmp(z,"-list")==0 ){
      modeChange(&data, MODE_List);
    }else if( cli_strcmp(z,"-quote")==0 ){
      modeChange(&data, MODE_Quote);
    }else if( cli_strcmp(z,"-line")==0 ){
      modeChange(&data, MODE_Line);
    }else if( cli_strcmp(z,"-column")==0 ){
      modeChange(&data, MODE_Column);
    }else if( cli_strcmp(z,"-json")==0 ){
      modeChange(&data, MODE_Json);
    }else if( cli_strcmp(z,"-markdown")==0 ){
      modeChange(&data, MODE_Markdown);
    }else if( cli_strcmp(z,"-table")==0 ){
      modeChange(&data, MODE_Table);
    }else if( cli_strcmp(z,"-psql")==0 ){
      modeChange(&data, MODE_Psql);
    }else if( cli_strcmp(z,"-box")==0 ){
      modeChange(&data, MODE_Box);
    }else if( cli_strcmp(z,"-csv")==0 ){
      modeChange(&data, MODE_Csv);
    }else if( cli_strcmp(z,"-escape")==0 && i+1<argc ){
      /* See similar code at tag-20250224-1 */
      const char *zEsc = argv[++i];
      int k;
      for(k=0; k<ArraySize(qrfEscNames); k++){
        if( sqlite3_stricmp(zEsc,qrfEscNames[k])==0 ){
          data.mode.spec.eEsc = k;
          break;
        }
      }
      if( k>=ArraySize(qrfEscNames) ){
        cli_printf(stderr, "unknown control character escape mode \"%s\""
                                " - choices:", zEsc);
        for(k=0; k<ArraySize(qrfEscNames); k++){
          cli_printf(stderr, " %s", qrfEscNames[k]);
        }
        cli_printf(stderr, "\n");
        exit(1);
      }
#ifdef SQLITE_HAVE_ZLIB
    }else if( cli_strcmp(z,"-zip")==0 ){
      data.openMode = SHELL_OPEN_ZIPFILE;
#endif
    }else if( cli_strcmp(z,"-append")==0 ){
      data.openMode = SHELL_OPEN_APPENDVFS;
#ifndef SQLITE_OMIT_DESERIALIZE
    }else if( cli_strcmp(z,"-deserialize")==0 ){
      data.openMode = SHELL_OPEN_DESERIALIZE;
    }else if( cli_strcmp(z,"-maxsize")==0 && i+1<argc ){
      data.szMax = integerValue(argv[++i]);
#endif
    }else if( cli_strcmp(z,"-readonly")==0 ){
      data.openFlags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
      data.openFlags |= SQLITE_OPEN_READONLY;
    }else if( cli_strcmp(z,"-nofollow")==0 ){
      data.openFlags |= SQLITE_OPEN_NOFOLLOW;
    }else if( cli_strcmp(z,"-noinit")==0 ){
      /* No-op */
    }else if( cli_strcmp(z,"-exclusive")==0 ){  /* UNDOCUMENTED */
      data.openFlags |= SQLITE_OPEN_EXCLUSIVE;
    }else if( cli_strcmp(z,"-ifexists")==0 ){
      data.openFlags &= ~(SQLITE_OPEN_CREATE);
      if( data.openFlags==0 ) data.openFlags = SQLITE_OPEN_READWRITE;
    }else if( cli_strcmp(z,"-ascii")==0 ){
      modeChange(&data, MODE_Ascii);
    }else if( cli_strcmp(z,"-tabs")==0 ){
      modeChange(&data, MODE_Tabs);
    }else if( cli_strcmp(z,"-separator")==0 ){
      modeSetStr(&data.mode.spec.zColumnSep, 
                       cmdline_option_value(argc,argv,++i));
    }else if( cli_strcmp(z,"-newline")==0 ){
      modeSetStr(&data.mode.spec.zRowSep, 
                       cmdline_option_value(argc,argv,++i));
    }else if( cli_strcmp(z,"-nullvalue")==0 ){
     modeSetStr(&data.mode.spec.zNull, 
                       cmdline_option_value(argc,argv,++i));
    }else if( cli_strcmp(z,"-header")==0 ){
      data.mode.spec.bTitles = QRF_Yes;
     }else if( cli_strcmp(z,"-noheader")==0 ){
      data.mode.spec.bTitles = QRF_No;
    }else if( cli_strcmp(z,"-echo")==0 ){
      data.mode.mFlags |= MFLG_ECHO;
    }else if( cli_strcmp(z,"-eqp")==0 ){
      data.mode.autoEQP = AUTOEQP_on;
    }else if( cli_strcmp(z,"-eqpfull")==0 ){
      data.mode.autoEQP = AUTOEQP_full;
    }else if( cli_strcmp(z,"-stats")==0 ){
      data.statsOn = 1;
    }else if( cli_strcmp(z,"-scanstats")==0 ){
      data.mode.scanstatsOn = 1;
    }else if( cli_strcmp(z,"-backslash")==0 ){
      /* Undocumented command-line option: -backslash
      ** Causes C-style backslash escapes to be evaluated in SQL statements
      ** prior to sending the SQL into SQLite.  Useful for injecting
      ** crazy bytes in the middle of SQL statements for testing and debugging.
      */
      ShellSetFlag(&data, SHFLG_Backslash);
    }else if( cli_strcmp(z,"-bail")==0 ){
      /* No-op.  The bail_on_error flag should already be set. */
    }else if( cli_strcmp(z,"-version")==0 ){
      cli_printf(stdout, "%s %s (%d-bit)\n",
            sqlite3_libversion(), sqlite3_sourceid(), 8*(int)sizeof(char*));
      rc = 0;
      goto shell_main_exit;
    }else if( cli_strcmp(z,"-interactive")==0 ){
      /* Need to check for interactive override here to so that it can
      ** affect console setup (for Windows only) and testing thereof.
      */
      stdin_is_interactive = 1;
    }else if( cli_strcmp(z,"-batch")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-screenwidth")==0 ){
      i++;      
    }else if( cli_strcmp(z,"-utf8")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-no-utf8")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-no-rowid-in-view")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-heap")==0 ){
      i++;
    }else if( cli_strcmp(z,"-pagecache")==0 ){
      i+=2;
    }else if( cli_strcmp(z,"-lookaside")==0 ){
      i+=2;
    }else if( cli_strcmp(z,"-threadsafe")==0 ){
      i+=2;
    }else if( cli_strcmp(z,"-nonce")==0 ){
      i += 2;
    }else if( cli_strcmp(z,"-mmap")==0 ){
      i++;
    }else if( cli_strcmp(z,"-memtrace")==0 ){
      i++;
    }else if( cli_strcmp(z,"-pcachetrace")==0 ){
      i++;
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
    }else if( cli_strcmp(z,"-sorterref")==0 ){
      i++;
#endif
    }else if( cli_strcmp(z,"-vfs")==0 ){
      i++;
    }else if( cli_strcmp(z,"-vfstrace")==0 ){
      i++;
#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( cli_strcmp(z,"-multiplex")==0 ){
      i++;
#endif
    }else if( cli_strcmp(z,"-help")==0 ){
      usage(1);
    }else if( cli_strcmp(z,"-cmd")==0 ){
      /* Run commands that follow -cmd first and separately from commands
      ** that simply appear on the command-line.  This seems goofy.  It would
      ** be better if all commands ran in the order that they appear.  But
      ** we retain the goofy behavior for historical compatibility. */
      if( i==argc-1 ) break;
      z = cmdline_option_value(argc,argv,++i);
      if( z[0]=='.' ){
        rc = do_meta_command(z, &data);
        if( rc && (bail_on_error || rc==2) ){
          if( rc==2 ) rc = 0;
          goto shell_main_exit;
        }
      }else{
        rc = runOneSqlLine(&data, z, "cmdline", i);
        if( bail_on_error ) goto shell_main_exit;
      }
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
    }else if( cli_strncmp(z, "-A", 2)==0 ){
      if( nCmd>0 ){
        cli_printf(stderr,"Error: cannot mix regular SQL or dot-commands"
              " with \"%s\"\n", z);
        rc = 1;
        goto shell_main_exit;
      }
      open_db(&data, OPEN_DB_ZIPFILE);
      if( z[2] ){
        argv[i] = &z[2];
        arDotCommand(&data, 1, argv+(i-1), argc-(i-1));
      }else{
        arDotCommand(&data, 1, argv+i, argc-i);
      }
      readStdin = 0;
      stdin_is_interactive = 0;
      break;
#endif
    }else if( cli_strcmp(z,"-safe")==0 ){
      data.bSafeMode = data.bSafeModePersist = 1;
    }else if( cli_strcmp(z,"-unsafe-testing")==0 ){
      /* Acted upon in first pass. */
    }else{
      cli_printf(stderr,"%s: Error: unknown option: %s\n", Argv0, z);
      eputz("Use -help for a list of options.\n");
      rc = 1;
      goto shell_main_exit;
    }
  }

  if( !readStdin ){
    /* Run all arguments that do not begin with '-' as if they were separate
    ** command-line inputs, except for the argToSkip argument which contains
    ** the database filename.
    */
    for(i=0; i<nCmd; i++){
      echo_group_input(&data, azCmd[i]);
      if( isScriptFile(azCmd[i],0) ){
        FILE *inSaved = data.in;
        i64 savedLineno = data.lineno;
        int res = 1;
        if( (data.in = openChrSource(azCmd[i]))!=0 ){
          res = process_input(&data, azCmd[i]);
          fclose(data.in);
        }
        data.in = inSaved;
        data.lineno = savedLineno;
        if( res ) i = nCmd;
      }else if( azCmd[i][0]=='.' ){
        char *zErrCtx = malloc( 64 );
        shell_check_oom(zErrCtx);
        sqlite3_snprintf(64,zErrCtx,"argv[%i]:",aiCmd[i]);
        data.zInFile = "<cmdline>";
        data.zErrPrefix = zErrCtx;
        rc = do_meta_command(azCmd[i], &data);
        free(data.zErrPrefix);
        data.zErrPrefix = 0;
        if( rc ){
          if( rc==2 ) rc = 0;
          goto shell_main_exit;
        }
      }else{
        rc = runOneSqlLine(&data, azCmd[i], "cmdline", aiCmd[i]);
        if( data.nPopMode ){
          modePop(&data);
          data.nPopMode = 0;
        }
      }
      if( data.nPopOutput && azCmd[i][0]!='.' ){
        output_reset(&data);
        data.nPopOutput = 0;
      }else{
        clearTempFile(&data);
      }
    }
  }else{
    /* Run commands received from standard input
    */
    if( stdin_is_interactive ){
      char *zHome;
      char *zHistory;
      cli_printf(stdout,
            "SQLite version %s %.19s\n" /*extra-version-info*/
            "Enter \".help\" for usage hints.\n",
            sqlite3_libversion(), sqlite3_sourceid());
      if( warnInmemoryDb ){
        sputz(stdout, "Connected to a ");
        printBold("transient in-memory database");
        sputz(stdout, ".\nUse \".open FILENAME\" to reopen on a"
              " persistent database.\n");
      }
      zHistory = getenv("SQLITE_HISTORY");
      if( zHistory ){
        zHistory = sqlite3_mprintf("%s", zHistory);
        shell_check_oom(zHistory);
      }else{
        zHistory = find_xdg_file("XDG_STATE_HOME",
                                 ".local/state",
                                 "sqlite_history");
        if( 0==zHistory && (zHome = find_home_dir(0))!=0 ){
          zHistory = sqlite3_mprintf("%s/.sqlite_history", zHome);
          shell_check_oom(zHistory);
        }
      }
      if( zHistory ){ shell_read_history(zHistory); }
#if (HAVE_READLINE || HAVE_EDITLINE) && !defined(SQLITE_OMIT_READLINE_COMPLETION)
      rl_attempted_completion_function = readline_completion;
#elif HAVE_LINENOISE==1
      linenoiseSetCompletionCallback(linenoise_completion);
#elif HAVE_LINENOISE==2
      linenoiseSetCompletionCallback(linenoise_completion, NULL);
#endif
      data.in = 0;
      rc = process_input(&data, "<stdin>");
      if( zHistory ){
        shell_stifle_history(2000);
        shell_write_history(zHistory);
        sqlite3_free(zHistory);
      }
    }else{
      data.in = stdin;
      rc = process_input(&data, "<stdin>");
    }
  }
#ifndef SQLITE_SHELL_FIDDLE
  /* In WASM mode we have to leave the db state in place so that
  ** client code can "push" SQL into it after this call returns. */
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && !defined(SQLITE_OMIT_AUTHORIZATION)
  if( data.expert.pExpert ){
    expertFinish(&data, 1, 0);
  }
#endif
 shell_main_exit:
  free(azCmd);
  free(aiCmd);
  set_table_name(&data, 0);
  if( data.db ){
    session_close_all(&data, -1);
    close_db(data.db);
  }
  for(i=0; i<ArraySize(data.aAuxDb); i++){
    sqlite3_free(data.aAuxDb[i].zFreeOnClose);
    if( data.aAuxDb[i].db ){
      session_close_all(&data, i);
      close_db(data.aAuxDb[i].db);
    }
  }
  find_home_dir(1);
  output_reset(&data);
  data.doXdgOpen = 0;
  clearTempFile(&data);
  modeFree(&data.mode);
  if( data.nSavedModes ){
    int ii;
    for(ii=0; ii<data.nSavedModes; ii++){
      modeFree(&data.aSavedModes[ii].mode);
      free(data.aSavedModes[ii].zTag);
    }
    free(data.aSavedModes);
  }
  free(data.zErrPrefix);
  free(data.zNonce);
  free(data.dot.zCopy);
  free(data.dot.azArg);
  free(data.dot.aiOfst);
  free(data.dot.abQuot);
  if( data.nTestRun ){
    sqlite3_fprintf(stdout, "%d test%s run with %d error%s\n",
       data.nTestRun, data.nTestRun==1 ? "" : "s",
       data.nTestErr, data.nTestErr==1 ? "" : "s");
    fflush(stdout);
    rc = data.nTestErr>0;
  }
  /* Clear the global data structure so that valgrind will detect memory
  ** leaks */
  memset(&data, 0, sizeof(data));
  if( bEnableVfstrace ){
    vfstrace_unregister("trace");
  }
  sqlite3_reset_auto_extension();
#ifdef SQLITE_DEBUG
  if( sqlite3_memory_used()>mem_main_enter ){
    cli_printf(stderr,"Memory leaked: %u bytes\n",
          (unsigned int)(sqlite3_memory_used()-mem_main_enter));
  }
#endif
#else /* SQLITE_SHELL_FIDDLE... */
  shell_main_exit:
#endif
  return rc;
}


#ifdef SQLITE_SHELL_FIDDLE
/* Only for emcc experimentation purposes. */
int fiddle_experiment(int a,int b){
  return a + b;
}

/*
** Returns a pointer to the current DB handle.
*/
sqlite3 * fiddle_db_handle(){
  return globalDb;
}

/*
** Returns a pointer to the given DB name's VFS. If zDbName is 0 then
** "main" is assumed. Returns 0 if no db with the given name is
** open.
*/
sqlite3_vfs * fiddle_db_vfs(const char *zDbName){
  sqlite3_vfs * pVfs = 0;
  if(globalDb){
    sqlite3_file_control(globalDb, zDbName ? zDbName : "main",
                         SQLITE_FCNTL_VFS_POINTER, &pVfs);
  }
  return pVfs;
}

/* Only for emcc experimentation purposes. */
sqlite3 * fiddle_db_arg(sqlite3 *arg){
    cli_printf(stdout, "fiddle_db_arg(%p)\n", (const void*)arg);
    return arg;
}

/*
** Intended to be called via a SharedWorker() while a separate
** SharedWorker() (which manages the wasm module) is performing work
** which should be interrupted. Unfortunately, SharedWorker is not
** portable enough to make real use of.
*/
void fiddle_interrupt(void){
  if( globalDb ) sqlite3_interrupt(globalDb);
}

/*
** Returns the filename of the given db name, assuming "main" if
** zDbName is NULL. Returns NULL if globalDb is not opened.
*/
const char * fiddle_db_filename(const char * zDbName){
    return globalDb
      ? sqlite3_db_filename(globalDb, zDbName ? zDbName : "main")
      : NULL;
}

/*
** Completely wipes out the contents of the currently-opened database
** but leaves its storage intact for reuse. If any transactions are
** active, they are forcibly rolled back.
*/
void fiddle_reset_db(void){
  if( globalDb ){
    int rc;
    while( sqlite3_txn_state(globalDb,0)>0 ){
      /*
      ** Resolve problem reported in
      ** https://sqlite.org/forum/forumpost/0b41a25d65
      */
      cli_puts("Rolling back in-progress transaction.\n", stdout);
      sqlite3_exec(globalDb,"ROLLBACK", 0, 0, 0);
    }
    rc = sqlite3_db_config(globalDb, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
    if( 0==rc ) sqlite3_exec(globalDb, "VACUUM", 0, 0, 0);
    sqlite3_db_config(globalDb, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
  }
}

/*
** Uses the current database's VFS xRead to stream the db file's
** contents out to the given callback. The callback gets a single
** chunk of size n (its 2nd argument) on each call and must return 0
** on success, non-0 on error. This function returns 0 on success,
** SQLITE_NOTFOUND if no db is open, or propagates any other non-0
** code from the callback. Note that this is not thread-friendly: it
** expects that it will be the only thread reading the db file and
** takes no measures to ensure that is the case.
*/
int fiddle_export_db( int (*xCallback)(unsigned const char *zOut, int n) ){
  sqlite3_int64 nSize = 0;
  sqlite3_int64 nPos = 0;
  sqlite3_file * pFile = 0;
  unsigned char buf[1024 * 8];
  int nBuf = (int)sizeof(buf);
  int rc = shellState.db
    ? sqlite3_file_control(shellState.db, "main",
                           SQLITE_FCNTL_FILE_POINTER, &pFile)
    : SQLITE_NOTFOUND;
  if( rc ) return rc;
  rc = pFile->pMethods->xFileSize(pFile, &nSize);
  if( rc ) return rc;
  if(nSize % nBuf){
    /* DB size is not an even multiple of the buffer size. Reduce
    ** buffer size so that we do not unduly inflate the db size when
    ** exporting. */
    if(0 == nSize % 4096) nBuf = 4096;
    else if(0 == nSize % 2048) nBuf = 2048;
    else if(0 == nSize % 1024) nBuf = 1024;
    else nBuf = 512;
  }
  for( ; 0==rc && nPos<nSize; nPos += nBuf ){
    rc = pFile->pMethods->xRead(pFile, buf, nBuf, nPos);
    if(SQLITE_IOERR_SHORT_READ == rc){
      rc = (nPos + nBuf) < nSize ? rc : 0/*assume EOF*/;
    }
    if( 0==rc ) rc = xCallback(buf, nBuf);
  }
  return rc;
}

/*
** Trivial exportable function for emscripten. It processes zSql as if
** it were input to the sqlite3 shell and redirects all output to the
** wasm binding. fiddle_main() must have been called before this
** is called, or results are undefined.
*/
void fiddle_exec(const char * zSql){
  if(zSql && *zSql){
    if('.'==*zSql) puts(zSql);
    shellState.wasm.zInput = zSql;
    shellState.wasm.zPos = zSql;
    process_input(&shellState, "<stdin>");
    shellState.wasm.zInput = shellState.wasm.zPos = 0;
  }
}
#endif /* SQLITE_SHELL_FIDDLE */
/************************* End src/shell.c.in ******************/
