强制文件下载 (Force download)

此代码片断可用于任意文件下载, 包括图片和HTML文件.
This codesnippet can be used to force a download of any type of file, including images and HTML pages.

<?php
/**
 * Force a file to be download instead of displayed.
 */
function force_download  ($filePath,  $name,  $mimetype = '')  { 
       // File's mimetype is not set? 
       if (empty($mimetype))  { 
               $mimetype = 'application/octet-stream'; 
       } 
 
       // Start sending headers 
       header("Pragma: public"); // required 
       header("Expires: 0"); 
       header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); 
       header("Cache-Control: private", false);   // required for certain browsers 
       header("Content-Transfer-Encoding: binary"); 
       header("Content-Type: " . $mimetype); 
       header("Content-Length: " . filesize($filePath)); 
       header("Content-Disposition: attachment; filename='" . $name . "';" ); 
 
       //read data 
       readfile($filePath); 
       exit();
}
?>