SQLite

          pDb->safety_level | (db->flags & PAGER_FLAGS_MASK));
    }
  }
}
#else
# define setDefaultSyncFlag(pBt,safety_level)
#endif

/* Forward declaration */
static int newDatabase(BtShared*);


/*
** Get a reference to pPage1 of the database file.  This will
** also acquire a readlock on that file.
**
** SQLITE_OK is returned on success.  If the file is not a
** well-formed database file, then SQLITE_CORRUPT is returned.

  /* Do some checking to help insure the file we opened really is
  ** a valid database file. 
  */
  nPage = nPageHeader = get4byte(28+(u8*)pPage1->aData);
  sqlite3PagerPagecount(pBt->pPager, &nPageFile);
  if( nPage==0 || memcmp(24+(u8*)pPage1->aData, 92+(u8*)pPage1->aData,4)!=0 ){
    nPage = nPageFile;
  }
  if( (pBt->db->flags & SQLITE_ResetDatabase)!=0 ){
    nPage = 0;
  }
  if( nPage>0 ){
    u32 pageSize;
    u32 usableSize;
    u8 *page1 = pPage1->aData;
    rc = SQLITE_NOTADB;
    /* EVIDENCE-OF: R-43737-39999 Every valid SQLite database file begins

        { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
        { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
        { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
        { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
        { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
        { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
        { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
        { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
      };
      unsigned int i;
      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
      for(i=0; i<ArraySize(aFlagOp); i++){
        if( aFlagOp[i].op==op ){
          int onoff = va_arg(ap, int);
          int *pRes = va_arg(ap, int*);

  **    meta[9]   unused
  **
  ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
  ** the possible values of meta[4].
  */
  for(i=0; i<ArraySize(meta); i++){
    sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
  }
  if( (db->flags & SQLITE_ResetDatabase)!=0 ){
    memset(meta, 0, sizeof(meta));
  }
  pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1];

  /* If opening a non-empty database, check the text encoding. For the
  ** main database, set sqlite3.enc to the encoding of the main database.
  ** For an attached db, it is an error if the encoding is not the same
  ** as sqlite3.enc.

  ".bail on|off           Stop after hitting an error.  Default OFF\n"
  ".binary on|off         Turn binary output on or off.  Default OFF\n"
  ".cd DIRECTORY          Change the working directory to DIRECTORY\n"
  ".changes on|off        Show number of rows changed by SQL\n"
  ".check GLOB            Fail if output since .testcase does not match\n"
  ".clone NEWDB           Clone data into NEWDB from the existing database\n"
  ".databases             List names and files of attached databases\n"
  ".dbconfig ?op? ?val?   List or change sqlite3_db_config() options\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"

    if( zErrMsg ){
      utf8_printf(stderr,"Error: %s\n", zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }
  }else

  if( c=='d' && n>=3 && strncmp(azArg[0], "dbconfig", n)==0 ){
    static const struct DbConfigChoices {const char *zName; int op;} aDbConfig[] = {
        { "enable_fkey",      SQLITE_DBCONFIG_ENABLE_FKEY            },
        { "enable_trigger",   SQLITE_DBCONFIG_ENABLE_TRIGGER         },
        { "fts3_tokenizer",   SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER  },
        { "load_extension",   SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION  },
        { "no_ckpt_on_close", SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE       },
        { "enable_qpsg",      SQLITE_DBCONFIG_ENABLE_QPSG            },
        { "trigger_eqp",      SQLITE_DBCONFIG_TRIGGER_EQP            },
        { "reset_database",   SQLITE_DBCONFIG_RESET_DATABASE         },
    };
    int ii, v;
    open_db(p, 0);
    for(ii=0; ii<ArraySize(aDbConfig); ii++){
      if( nArg>1 && strcmp(azArg[1], aDbConfig[ii].zName)!=0 ) continue;
      if( nArg>=3 ){
        sqlite3_db_config(p->db, aDbConfig[ii].op, booleanValue(azArg[2]), 0);
      }
      sqlite3_db_config(p->db, aDbConfig[ii].op, -1, &v);
      utf8_printf(p->out, "%18s %s\n", aDbConfig[ii].zName, v ? "on" : "off");
      if( nArg>1 ) break;
    }
    if( nArg>1 && ii==ArraySize(aDbConfig) ){
      utf8_printf(stderr, "Error: unknown dbconfig \"%s\"\n", azArg[1]);
      utf8_printf(stderr, "Enter \".dbconfig\" with no arguments for a list\n");
    }   
  }else

  if( c=='d' && n>=3 && strncmp(azArg[0], "dbinfo", n)==0 ){
    rc = shell_dbinfo_command(p, nArg, azArg);
  }else

  if( c=='d' && strncmp(azArg[0], "dump", n)==0 ){
    const char *zLike = 0;
    int i;
    int savedShowHeader = p->showHeader;

** behavior. The first parameter passed to this operation is an integer -
** positive to enable output for trigger programs, or zero to disable it,
** or negative to leave the setting unchanged.
** The second parameter is a pointer to an integer into which is written 
** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 
** it is not disabled, 1 if it is.  
** </dd>
**
** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
** [VACUUM] in order to reset a database back to an empty database
** with no schema and no content. The following process works even for
** a badly corrupted database file:
** <ol>
** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
** </ol>
** Because resetting a database is destructive and irreversible, the
** process requires the use of this obscure API and multiple steps to help
** ensure that it does not happen by accident.
** </dd>
** </dl>
*/
#define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
#define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
#define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
#define SQLITE_DBCONFIG_MAX                   1009 /* Largest DBCONFIG */

/*
** CAPI3REF: Enable Or Disable Extended Result Codes
** METHOD: sqlite3
**
** ^The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. ^The extended result

#define SQLITE_EnableTrigger  0x00040000  /* True to enable triggers */
#define SQLITE_DeferFKs       0x00080000  /* Defer all FK constraints */
#define SQLITE_QueryOnly      0x00100000  /* Disable database changes */
#define SQLITE_CellSizeCk     0x00200000  /* Check btree cell sizes on load */
#define SQLITE_Fts3Tokenizer  0x00400000  /* Enable fts3_tokenizer(2) */
#define SQLITE_EnableQPSG     0x00800000  /* Query Planner Stability Guarantee*/
#define SQLITE_TriggerEQP     0x01000000  /* Show trigger EXPLAIN QUERY PLAN */
#define SQLITE_ResetDatabase  0x02000000  /* Reset the database */

/* Flags used only if debugging */
#ifdef SQLITE_DEBUG
#define SQLITE_SqlTrace       0x08000000  /* Debug print SQL as it executes */
#define SQLITE_VdbeListing    0x10000000  /* Debug listings of VDBE programs */
#define SQLITE_VdbeTrace      0x20000000  /* True to trace VDBE execution */
#define SQLITE_VdbeAddopTrace 0x40000000  /* Trace sqlite3VdbeAddOp() calls */

  } aSetting[] = {
    { "FKEY",            SQLITE_DBCONFIG_ENABLE_FKEY },
    { "TRIGGER",         SQLITE_DBCONFIG_ENABLE_TRIGGER },
    { "FTS3_TOKENIZER",  SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER },
    { "LOAD_EXTENSION",  SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
    { "NO_CKPT_ON_CLOSE",SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE },
    { "QPSG",            SQLITE_DBCONFIG_ENABLE_QPSG },
    { "TRIGGER_EQP",     SQLITE_DBCONFIG_TRIGGER_EQP },
    { "RESET_DB",        SQLITE_DBCONFIG_RESET_DATABASE },
  };
  int i;
  int v;
  const char *zSetting;
  sqlite3 *db;

  if( objc!=4 ){