Using php to force download a pdf

Question

Im trying to get a website to have a button that forces a download of a pdf.

Heres the html of the button:

Answer 1

$file_url = www.example.com/pdffolder/$pdfname;
header('Content-Type: application/pdf');
header("Content-Transfer-Encoding: Binary");
header("Content-disposition: attachment; filename=".$pdfname);
readfile($file_url);