将文件夹压缩成zip文件的php代码

            @set_time_limit("0");
            if (is_array($dir)){
                $fd = fopen ($dir, "r");
                $fileValue = fread ($fd, filesize ($filename));
                fclose ($fd);
                if (is_array($dir)) $filename = basename($dir);
                $this -> addFile($fileValue, "$filename");
            }else{
                $this->dirTree($dir,$dir);
            }

            $zipfilenametemp = time().$zipfilename;
            $out = $this -> filezip();
            $fp = fopen($zipfilenametemp, "w");
            fwrite($fp, $out, strlen($out));
            fclose($fp);
            $filesize = filesize($zipfilenametemp);

            if ($filesize < 104857600) {
                if($autoDownload){
                    header("Content-type: application/octet-stream");
                    header("Content-disposition: attachment; filename=".$zipfilename);
                }
                echo $this -> filezip();
            }else{
                echo "create zip error!";
            }
            unlink($zipfilenametemp);
        }