<"\n\n";
    break;
   case 'br':
   case 'div':
   case 'p':
    $str .= "\n";
    break;
   case 'img':
   case 'span':
    break;
   case 'obj':
    $tmp = '(' . self::parseNode($node['data'][0]) . ')';
    $str .= str_replace("\n", '', $tmp);
    break;
   default:
    trigger_error('Unkown type:'.$node['t'], E_USER_WARNING);
    break;
  }
  return $str;
 }
 public function get($page = 1){
  echo "getting page {$page}...\n";
  $ch = curl_init();
  $url = sprintf('http://wenku.baidu.com/content/%s/"save to {$path}\n";
 }
}
//使用示例
$yuedu = new BaiduYuedu('49422a3769eae009581becba', '8ed1dedb240b11bf0731336eff95093f', '你的百度域cookie');
$yuedu->start();
$yuedu->saveTo('result.txt');