php 删除图片代码

if(isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'){
            $url = $_GET['json'];
            $url = $_SERVER['DOCUMENT_ROOT'].urldecode($url['picurl']);
            $pictype = array("gif","jpg","jpeg","png","bmp");
            if(file_exists($url)){
                $infos = pathinfo($url);
                if(in_array($infos['extension'],$pictype) && strpos($url,"uploadfile")){
                    if(unlink($url)){
                        echo json_encode(array("status"=>"1","info"=>L('删除成功!')));
                    }else{
                        echo json_encode(array("status"=>"2","info"=>L("删除失败，请检查权限!")));
                    }
                }else{
                    echo json_encode(array("status"=>"2","info"=>L("删除失败，请检查权限!")));
                }

            }else{
                echo json_encode(array("status"=>"0","info"=>L("文件不存在或已删除")));
            }
        }
//该片段来自于http://outofmemory.cn