[HN4E7O]

внимание правильный ответ

 
    $post = $_POST["archivo"];
    $f = "http://localhost/opcion1/folletos/".$post;
    header('Content-type: application/pdf');
    header("Content-Disposition: attachment; filename=\"".$post."\"\n");
   $fp=fopen("$f", "r");
   fpassthru($fp);