: youtube-mp4-url ( url -- url ) http-get nip dup [ "&video_id=" swap start ] [ "&title=" swap start ] bi rot subseq "http://www.youtube.com/get_video.php?" prepend "&fmt=18" append ; "http://www.youtube.com/watch?v=foobarbaz" youtube-mp4-url http-get nip "foo.mp4" download-to