php 文件下载

<?php


//文件下载
$file = './../1.xls'; 


if (file_exists($file)) { 
header('Content-Description: File Transfer'); 
header('Content-Type: application/octet-stream'); 
header('Content-Disposition: attachment; filename='.basename($file)); 
//header('Content-Disposition: attachment; filename="'.$filename.'"'); 
header('Content-Transfer-Encoding: binary'); 
header('Expires: 0'); 
header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
header('Pragma: public'); 
header('Content-Length: ' . filesize($file)); 
ob_clean(); 
flush(); 
readfile($file); 
exit; 
}
?>