php实现上传文件并解压

<?php//上传RAR压缩包并解压//获取当前文件$dir=getcwd();if(isset($_POST['sub'])){    $tname=$_FILES['upfiles']['tmp_name'];    $nname=$_FILES['upfiles']['name'];    move_uploaded_file($tname,$nname);    $obj=new COM('Wscript.Shell');    //执行doc解压命令    $obj->run('winrar x $dir\\".$nname." ".$dir,1,true');    //删除上传的文件    unlink($nname);}?><form action='index.php' method="post" enctype="multipart/form-data">    <input type="file" name="upfiles">    <input type="submit" name="sub" value="上传并解压"></form>