php批量转换文件夹下所有文件编码的函数类

<"$filename/*") as $key=>$value)
      {
        iconv_file($value);
      }
    }
    else
    {
      $contents_before = file_get_contents($filename);
      /*$encoding = mb_detect_encoding($contents_before,array('CP936','ASCII','GBK','GB2312','UTF-8'));
      echo $encoding;
      if($encoding=='UTF-8') mb_detect_encoding函数不工作
      {
        return;
      }*/
      $contents_after = iconv($input_encoding,$output_encoding,$contents_before);
      file_put_contents($filename, $contents_after);
    }
  }
  else
  {
    echo '参数错误';
    return false;
  }
}
iconv_file('./test');
?>