PHP代码:

// write to tmp file, then rename it to avoid
 // file locking race condition
    $_tmp_file = tempnam($_dirname, 'wrt');
    if (!($fd = @fopen($_tmp_file, 'wb'))) {
        $_tmp_file = $_dirname . DIRECTORY_SEPARATOR . uniqid('wrt');
        if (!($fd = @fopen($_tmp_file, 'wb'))) {
            $smarty->trigger_error("problem writing temporary file '$_tmp_file'");
            return false;
        }
    }
   fwrite($fd, $params['contents']);
   fclose($fd);