如何使用PHP强制文件下载？

<?php
   header(&#39;Content-type: text/javascript&#39;);
   header(&#39;Content-Disposition: attachment; filename="file.js"&#39;);
   readfile(file that is downloaded.js&#39;); //This can be printed for verification purpose
?>

AddType application/octet-stream csv
header('Content-Type: application/csv');
header('Content-Disposition: attachment; filename=name of csv file');
header('Pragma: no-cache');
readfile("path-to-csv-file");