SQLite

    return SQLITE_IOERR_READ;
  }
  nRead = read(p->fd, zBuf, iAmt);

  if( nRead==iAmt ){
    return SQLITE_OK;
  }else if( nRead>=0 ){
    if( nRead<iAmt ){
      memset(&((char*)zBuf)[nRead], 0, iAmt-nRead);
    }
    return SQLITE_IOERR_SHORT_READ;
  }

  return SQLITE_IOERR_READ;
}

/*

  return SQLITE_OK;
}

/*
** No xFileControl() verbs are implemented by this VFS.
*/
static int demoFileControl(sqlite3_file *pFile, int op, void *pArg){
  return SQLITE_OK;
  return SQLITE_NOTFOUND;
}

/*
** The xSectorSize() and xDeviceCharacteristics() methods. These two
** may return special values allowing SQLite to optimize file-system 
** access to some extent. But it is also safe to simply return 0.
*/