private function rename($oldname, $newname)
{
    $result = false;

    $old = self::$root_path.$oldname;
    $new = self::$root_path.$newname;

    @exec('mv "' . $old . '" "' . $new . '"', $output, $return_val);

    if ($return_val == 0) {
        $result = true;
        $this->writeLog(__METHOD__.' replace current version code', self::LOG_TRACE, compact('oldname', 'newname'));
    }
    return $result;
}