Discuz某文库插件任意本地下载

$doc=$_GET['doc'];$doc="../../../".$doc;$filename=$_GET['filename'];    $ext=$_GET['ext'];//设置文件类型if($ext=='doc')  {$_ext="application/msword";}if($ext=='xls')  {$_ext="application/vnd.ms-excel";}if($ext=='ppt')  {$_ext="application/vnd.ms-powerpoint";}if($ext=='docx') {$_ext="application/vnd.openxmlformats-officedocument.wordprocessingml.template";}if($ext=='xlsx') {$_ext="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";}if($ext=='pptx') {$_ext="application/vnd.openxmlformats-officedocument.presentationml.presentation";}if($ext=='pdf')  {$_ext="application/pdf";}if($ext=='txt')  {$_ext="application/plain";}//设置文件头header('Content-Disposition: attachment; filename='.$filename);header('Content-Type:'.$_ext);header('Content-Length:'.filesize($doc));//读取文件readfile($doc);?>