Download file indirectly

download-page

if(false == isset($_GET['f'])):
    wp_redirect($_SERVER['HTTP_REFERER']);
    exit();
endif;


$path = '/uploads';
$path = $path. '/'. $_GET['f'];
$filename = $_GET['f'];

$mm_type="application/octet-stream"; // modify accordingly to the file type of $path, but in most cases no need to do so

header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: public");
header("Content-Description: File Transfer");
header("Content-Type: " . $mm_type);
header("Content-Length: " .(string)(filesize($path)) );
header('Content-Disposition: attachment; filename="'. $filename .'"');
header("Content-Transfer-Encoding: binary\n");

readfile($path); // outputs the content of the file

exit();