Show HN: Two-faced URLs

by ipsin on 7/6/2011, 3:37 PM with 16 comments
  • by ipsin on 7/6/2011, 3:51 PM

    This is a URL shortener that gives a link that sends "preview" processes one place and actual users somewhere else. It works for google plus and facebook and several other "preview" bots. Proof-of-concept because I don't like URL shorteners in general, but it links to a restricted list of sites.

  • by pak on 7/6/2011, 4:48 PM

    Yet another reason for URL shorteners to be banished from the web (not that this will ever happen). Besides the arcane input requirements of Twitter and the semi-retarded behavior of certain email clients, I haven't found a good use case for them that couldn't have been solved better with proper link formatting or better content presentation.

    When the web is just a sea of opaque pointers to pointers to pointers, with various hilarity like these URLs mixed in, we'll all wonder why the hell we stood by and let it happen.

  • by ipsin on 7/6/2011, 4:28 PM

    It's actually several things, including user agent strings, HTTP accept/accept language.

    The underlying script allows you to route between n different destinations based on header matching and netmasks. The shortened URL is just a hash of the rule set, with a sequence number appended in case of collisions.

  • by billpg on 7/6/2011, 4:57 PM

    That's one thing that mildly annoys me about twitter. It clearly knows where a shortened link is heading because it reveals the full URL on the mouseover. Given that information, why does it need the shortened link any more?

  • by bgarbiak on 7/6/2011, 6:59 PM

    This actually could be quite useful. Sometimes people need to post a nicely described link with an adequate thumbnail, yet the Facebook bot finds only some random image. With this little service one can prepare a dummy page for illustrative purposes and then let brokenthings.org handle the bot and the redirection.

  • by lawn on 7/6/2011, 5:09 PM

    I've been waiting for this since url shorteners came to be. Sadly I don't think shorteners will loose popularity anytime soon and I will continue to avoid them as I've always done.

  • by rmccue on 7/6/2011, 4:14 PM

    At a guess: HEAD requests give one URL, GET requests give another?

  • by TobbenTM on 7/8/2011, 7:09 AM

    This is not working for me.. Whenever I change the source link, Facebook gives me no preview..

  • by makethetick on 7/6/2011, 3:59 PM

    Very clever/sneaky!

  • by jasondavies on 7/6/2011, 4:44 PM

    To defend against this, social networking sites should simply cache the link that the preview bot sees, and send users there directly instead.

  • by inportb on 7/6/2011, 3:49 PM

    Clever use of content negotiation!

  • by lbarrow on 7/6/2011, 4:55 PM

    This is great! Lots of fun.