php – How to force download of a file?

You could try something like this:

$file_name="file.avi";
$file_url="http://www.myremoteserver.com/" . $file_name;
header('Content-Type: application/octet-stream');
header("Content-Transfer-Encoding: Binary"); 
header("Content-disposition: attachment; filename=\"".$file_name."\""); 
readfile($file_url);
exit;

I just tested it and it works for me.

Please note that for readfile to be able to read a remote url, you need to have your fopen_wrappers enabled.