通过php下载.torrent文件，无效的Bencoding

Question

I'm writing a custom php application that should allow downloading of torrent files. Files are located on the server, and per user request,I serve the file the following way:

    if( file_exists( $torrent_file ) ) {
        header("Content-type: application/x-bittorrent");
        header('Content-Length: ' . filesize( $torrent_file ));
        header('Content-Disposition: attachment; filename="' . basename( $torrent_file ).'"');

        readfile($torrent_file);
    }

But when I download and try to add the file to uTorrent I see the following error:

Unable to load - Torrent is not valid Bencoding.

I searched around to find a solution to this exact problem without any success.

Answer 1

After nearly a day of searching and googling, i found the problem. It appeared that there was a trailing whitespace after the closing php tag, inside one of the included php files. I removed the whitespace along with the closing tag and the problem was fixed.