SQLite

struct ShellState {
  sqlite3 *db;           /* The database */
  u8 autoExplain;        /* Automatically turn on .explain mode */
  u8 autoEQP;            /* Run EXPLAIN QUERY PLAN prior to seach SQL stmt */
  u8 statsOn;            /* True to display memory stats before each finalize */
  u8 scanstatsOn;        /* True to display scan stats before each finalize */
  u8 openMode;           /* SHELL_OPEN_NORMAL, _APPENDVFS, or _ZIPFILE */
  u8 doXdgOpen;          /* Invoke start/open/xdg-open in output_reset() */
  int outCount;          /* Revert to stdout when reaching zero */
  int cnt;               /* Number of records displayed so far */
  FILE *out;             /* Write results here */
  FILE *traceOut;        /* Output for sqlite3_trace() */
  int nErr;              /* Number of errors seen */
  int mode;              /* An output mode setting */
  int cMode;             /* temporary output mode for the current query */
  int normalMode;        /* Output mode before ".explain on" */
  int writableSchema;    /* True if PRAGMA writable_schema=ON */
  int showHeader;        /* True to show column names in List or Column mode */
  int nCheck;            /* Number of ".check" commands run */
  unsigned shellFlgs;    /* Various flags */
  char *zDestTable;      /* Name of destination table when MODE_Insert */
  char *zTempFile;       /* Temporary file that might need deleting */
  char zTestcase[30];    /* Name of current test case */
  char colSeparator[20]; /* Column separator character for several modes */
  char rowSeparator[20]; /* Row separator character for MODE_Ascii */
  int colWidth[100];     /* Requested width of each column when in column mode*/
  int actualWidth[100];  /* Actual width of each column */
  char nullValue[20];    /* The text to print when a NULL comes back from
                         ** the database */

  ".databases             List names and files of attached databases\n"
  ".dbinfo ?DB?           Show status information about the database\n"
  ".dump ?TABLE? ...      Dump the database in an SQL text format\n"
  "                         If TABLE specified, only dump tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".echo on|off           Turn command echo on or off\n"
  ".eqp on|off|full       Enable or disable automatic EXPLAIN QUERY PLAN\n"
  ".excel                 Display the output of next command in a spreadsheet\n"
  ".exit                  Exit this program\n"
  ".expert                EXPERIMENTAL. Suggest indexes for specified queries\n"
/* Because explain mode comes on automatically now, the ".explain" mode
** is removed from the help screen.  It is still supported for legacy, however */
/*".explain ?on|off|auto? Turn EXPLAIN output mode on or off or to automatic\n"*/
  ".fullschema ?--indent? Show schema and the content of sqlite_stat tables\n"
  ".headers on|off        Turn display of headers on or off\n"

    sqlite3_exec(newDb, "COMMIT;", 0, 0, 0);
    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
  }
  sqlite3_close(newDb);
}

/*
** 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{
    output_file_close(p->out);
    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);
      system(zCmd);
      sqlite3_free(zCmd);
      p->mode = p->doXdgOpen - 1;
      p->doXdgOpen = 0;
    }
  }
  p->outfile[0] = 0;
  p->out = stdout;
}

/*
** Run an SQL command and return the single integer result.

  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( shellDeleteFile(p->zTempFile) ) return;
  sqlite3_free(p->zTempFile);
  p->zTempFile = 0;
}

/*
** Create a new temp file name with the given suffix.
*/
static void newTempFile(ShellState *p, const char *zSuffix){
  clearTempFile(p);
  sqlite3_free(p->zTempFile);
  p->zTempFile = 0;
  sqlite3_file_control(p->db, 0, SQLITE_FCNTL_TEMPFILENAME, &p->zTempFile);
  if( p->zTempFile==0 ){
    sqlite3_uint64 r;
    sqlite3_randomness(sizeof(r), &r);
    p->zTempFile = sqlite3_mprintf("temp%llx.%s", r, zSuffix);
  }else{
    p->zTempFile = sqlite3_mprintf("%z.%s", p->zTempFile, zSuffix);
  }
  if( p->zTempFile==0 ){
    raw_printf(stderr, "out of memory\n");
    exit(1);
  }
}


/*
** 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.

  }

  /* 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' && strncmp(azArg[0], "auth", n)==0 ){
    if( nArg!=2 ){
      raw_printf(stderr, "Usage: .auth ON|OFF\n");
      rc = 1;
      goto meta_command_exit;

    if( p->db==0 ){
      /* As a fall-back open a TEMP database */
      p->zDbFilename = 0;
      open_db(p, 0);
    }
  }else

  if( (c=='o'
        && (strncmp(azArg[0], "output", n)==0||strncmp(azArg[0], "once", n)==0))
   || (c=='e' && n==5 && strcmp(azArg[0],"excel")==0)
  ){
    const char *zFile = nArg>=2 ? azArg[1] : "stdout";
    if( azArg[0][0]=='e' ){
      /* Transform the ".excel" command into ".once -x" */
      nArg = 2;
      azArg[0] = "once";
      zFile = azArg[1] = "-x";
      n = 4;
    }
    if( nArg>2 ){
      utf8_printf(stderr, "Usage: .%s [-e|-x|FILE]\n", azArg[0]);
      rc = 1;
      goto meta_command_exit;
    }
    if( n>1 && strncmp(azArg[0], "once", n)==0 ){
      if( nArg<2 ){
        raw_printf(stderr, "Usage: .once (-e|-x|FILE)\n");
        rc = 1;
        goto meta_command_exit;
      }
      p->outCount = 2;
    }else{
      p->outCount = 0;
    }
    output_reset(p);
    if( zFile[0]=='-' && zFile[1]=='-' ) zFile++;
    if( strcmp(zFile, "-e")==0 || strcmp(zFile, "-x")==0 ){
      p->doXdgOpen = p->mode + 1;
      if( zFile[1]=='x' ){
        newTempFile(p, "csv");
        p->mode = MODE_Csv;
        sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Comma);
        sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_CrLf);
      }else{
        newTempFile(p, "txt");
      }
      zFile = p->zTempFile;
    }
    if( zFile[0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
      raw_printf(stderr, "Error: pipes are not supported in this OS\n");
      rc = 1;
      p->out = stdout;
#else
      p->out = popen(zFile + 1, "w");

    if( nSql && line_contains_semicolon(&zSql[nSqlPrior], nSql-nSqlPrior)
                && sqlite3_complete(zSql) ){
      errCnt += runOneSqlLine(p, zSql, in, startline);
      nSql = 0;
      if( p->outCount ){
        output_reset(p);
        p->outCount = 0;
      }else{
        clearTempFile(p);
      }
    }else if( nSql && _all_whitespace(zSql) ){
      if( ShellHasFlag(p, SHFLG_Echo) ) printf("%s\n", zSql);
      nSql = 0;
    }
  }
  if( nSql && !_all_whitespace(zSql) ){

  set_table_name(&data, 0);
  if( data.db ){
    session_close_all(&data);
    sqlite3_close(data.db);
  }
  sqlite3_free(data.zFreeOnClose);
  find_home_dir(1);
  clearTempFile(&data);
#if !SQLITE_SHELL_IS_UTF8
  for(i=0; i<argc; i++) sqlite3_free(argv[i]);
  sqlite3_free(argv);
#endif
  return rc;
}