private static function check_path($path, $op_user)
 {
     // 1. check length
     $snappath = SnapShotUtil::getSnapShotPath($path, $op_user);
     $snappath_length = strlen($snappath);
     if ($snappath_length >= InfoDescUtil::SNAPSHOT_PATH_MAX_LENGTH) {
         QconfMgrLog::err(__FILE__, __LINE__, "path of snapshot is too long, path_lengrh({$snappath_length})");
         return InfoDescUtil::ERR_SNAPSHOT_PATH_TO_LONG;
     }
     // 2. check character
     $path_reg = "/^[\\w\\d_\\-\\.:\\/]+\$/";
     $is_illegal = preg_match($path_reg, $path);
     if ($is_illegal === 0) {
         QconfMgrLog::err(__FILE__, __LINE__, "illegal path, path({$path})");
         return InfoDescUtil::ERR_SNAPSHOT_PATH_ILLEGAL;
     }
     return InfoDescUtil::QCONF_OK;
 }