SQLite

  for(i=0; n>0 && i<8; n--, a++){
    if( isxdigit(a[0]) ) buf[i++] = a[0];
  }
  if( i==8 && memcmp(buf,"53514c69",8)==0 ) return 1;
  return 0;
}

/* Implementation of the isdbsql(TEXT) SQL function.
*/
static void isDbSqlFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int n = sqlite3_value_bytes(argv[0]);
  unsigned char *a = (unsigned char*)sqlite3_value_blob(argv[0]);
  sqlite3_result_int(context, a!=0 && n>0 && isDbSql(a,n));
}

/* Methods for the VHandle object
*/
static int inmemClose(sqlite3_file *pFile){
  VHandle *p = (VHandle*)pFile;
  VFile *pVFile = p->pVFile;
  pVFile->nRef--;

/*
** Rebuild the database file.
**
**    (1)  Remove duplicate entries
**    (2)  Put all entries in order
**    (3)  Vacuum
*/
static void rebuild_database(sqlite3 *db, int dbSqlOnly){
  int rc;
  char *zSql;
  zSql = sqlite3_mprintf(
     "BEGIN;\n"
     "CREATE TEMP TABLE dbx AS SELECT DISTINCT dbcontent FROM db;\n"
     "DELETE FROM db;\n"
     "INSERT INTO db(dbid, dbcontent) "
        " SELECT NULL, dbcontent FROM dbx ORDER BY 2;\n"
     "DROP TABLE dbx;\n"
     "CREATE TEMP TABLE sx AS SELECT DISTINCT sqltext FROM xsql %s;\n"
     "DELETE FROM xsql;\n"
     "INSERT INTO xsql(sqlid,sqltext) "
        " SELECT NULL, sqltext FROM sx ORDER BY 2;\n"
     "DROP TABLE sx;\n"
     "COMMIT;\n"
     "PRAGMA page_size=1024;\n"
     "VACUUM;\n",
     dbSqlOnly ? " WHERE isdbsql(sqltext)" : ""
  );
  rc = sqlite3_exec(db, zSql, 0, 0, 0);
  sqlite3_free(zSql);
  if( rc ) fatalError("cannot rebuild: %s", sqlite3_errmsg(db));
}

/*
** Return the value of a hexadecimal digit.  Return -1 if the input
** is not a hex digit.
*/

"  --export-sql DIR     Write SQL to file(s) in DIR. Also works with --sqlid\n"
"  --help               Show this help text\n"
"  --info               Show information about SOURCE-DB w/o running tests\n"
"  --limit-mem N        Limit memory used by test SQLite instance to N bytes\n"
"  --limit-vdbe         Panic if any test runs for more than 100,000 cycles\n"
"  --load-sql ARGS...   Load SQL scripts fron files into SOURCE-DB\n"
"  --load-db ARGS...    Load template databases from files into SOURCE_DB\n"
"  --load-dbsql ARGS..  Load dbsqlfuzz outputs into the xsql table\n"
"  -m TEXT              Add a description to the database\n"
"  --native-vfs         Use the native VFS for initially empty database files\n"
"  --native-malloc      Turn off MEMSYS3/5 and Lookaside\n"
"  --oss-fuzz           Enable OSS-FUZZ testing\n"
"  --prng-seed N        Seed value for the PRGN inside of SQLite\n"
"  -q|--quiet           Reduced output\n"
"  --rebuild            Rebuild and vacuum the database file\n"

  int iFirstInsArg = 0;        /* First argv[] for --load-db or --load-sql */
  sqlite3 *db = 0;             /* The open database connection */
  sqlite3_stmt *pStmt;         /* A prepared statement */
  int rc;                      /* Result code from SQLite interface calls */
  Blob *pSql;                  /* For looping over SQL scripts */
  Blob *pDb;                   /* For looping over template databases */
  int i;                       /* Loop index for the argv[] loop */
  int dbSqlOnly = 0;           /* Only use scripts that are dbsqlfuzz */
  int onlySqlid = -1;          /* --sqlid */
  int onlyDbid = -1;           /* --dbid */
  int nativeFlag = 0;          /* --native-vfs */
  int rebuildFlag = 0;         /* --rebuild */
  int vdbeLimitFlag = 0;       /* --limit-vdbe */
  int infoFlag = 0;            /* --info */
  int timeoutTest = 0;         /* undocumented --timeout-test flag */

        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        onlyDbid = integerValue(argv[++i]);
      }else
      if( strcmp(z,"export-db")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        zExpDb = argv[++i];
      }else
      if( strcmp(z,"export-sql")==0 || strcmp(z,"export-dbsql")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        zExpSql = argv[++i];
      }else
      if( strcmp(z,"help")==0 ){
        showHelp();
        return 0;
      }else

        break;
      }else
      if( strcmp(z,"load-db")==0 ){
        zInsSql = "INSERT INTO db(dbcontent) VALUES(readfile(?1))";
        iFirstInsArg = i+1;
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
        break;
      }else
      if( strcmp(z,"load-dbsql")==0 ){
        zInsSql = "INSERT INTO xsql(sqltext)VALUES(CAST(readfile(?1) AS text))";
        iFirstInsArg = i+1;
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
        dbSqlOnly = 1;
        break;
      }else
      if( strcmp(z,"m")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        zMsg = argv[++i];
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
      }else
      if( strcmp(z,"native-malloc")==0 ){

      }
      sqlite3_finalize(pStmt);
    }

    if( zInsSql ){
      sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0,
                              readfileFunc, 0, 0);
      sqlite3_create_function(db, "isdbsql", 1, SQLITE_UTF8, 0,
                              isDbSqlFunc, 0, 0);
      rc = sqlite3_prepare_v2(db, zInsSql, -1, &pStmt, 0);
      if( rc ) fatalError("cannot prepare statement [%s]: %s",
                          zInsSql, sqlite3_errmsg(db));
      rc = sqlite3_exec(db, "BEGIN", 0, 0, 0);
      if( rc ) fatalError("cannot start a transaction");
      for(i=iFirstInsArg; i<argc; i++){
        sqlite3_bind_text(pStmt, 1, argv[i], -1, SQLITE_STATIC);
        sqlite3_step(pStmt);
        rc = sqlite3_reset(pStmt);
        if( rc ) fatalError("insert failed for %s", argv[i]);
      }
      sqlite3_finalize(pStmt);
      rc = sqlite3_exec(db, "COMMIT", 0, 0, 0);
      if( rc ) fatalError("cannot commit the transaction: %s",
                          sqlite3_errmsg(db));
      rebuild_database(db, dbSqlOnly);
      sqlite3_close(db);
      return 0;
    }
    rc = sqlite3_exec(db, "PRAGMA query_only=1;", 0, 0, 0);
    if( rc ) fatalError("cannot set database to query-only");
    if( zExpDb!=0 || zExpSql!=0 ){
      sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0,

    /* Rebuild the database, if requested */
    if( rebuildFlag ){
      if( !quietFlag ){
        printf("%s: rebuilding... ", zDbName);
        fflush(stdout);
      }
      rebuild_database(db, 0);
      if( !quietFlag ) printf("done\n");
    }
  
    /* Close the source database.  Verify that no SQLite memory allocations are
    ** outstanding.
    */
    sqlite3_close(db);