code: public function dir_readdir()
      {
          if (!$this->handle) {
              return false;
          }
          self::restorePrev();
          $success = \readdir($this->handle);
          self::register();
          return $success;
      }
docs: Read a single filename of a directory
  
  @return string|boolean
  
  @see http://php.net/manual/en/streamwrapper.dir-readdir.php