php怎麼實作文字刪除功能

<?php
    function deldir($dirname){
        if(!file_exists($dirname)){    
            die("文件不存在");
        }
        if(is_file($dirname)){
            unlink($dirname);
        }else{
            $dir = opendir($dirname);
            while ($filename = readdir($dir)) {
                if($filename != "." && $filename != ".."){
                    $filename = $dirname."/".$filename;
                    if(is_dir($filename)){
                        deldir($filename);    //用递归遍历目录
                    }else{
                        unlink($filename);
                    }
                }
            }
            closedir($dir);
            rmdir($dirname);
        }
    }