How do you initiate/force a download for files that reside externally in PHP or other language?

Question

If you have images or other files that reside externally, how do force the browser to download the link when a user click on it?

The use of \"Content-disposition: attac

Answer 1

I use a combination of the aforementioned "Content-Disposition" header, as well as forcing the type:

header("Content-type: attachment/octet-stream");
header('Content-disposition: attachment; filename="'.$filename.'"');