Apropos of my recent interview with Tantek Çelik about URL shorteners, I’ve ported his NewBase60 code (part of his CASSIS project) to perl. It’s now found on github at http://github.com/sivy/TinWhistle. This code converts numbers (in this case, dates expressed as days-since-the-epoch) into a base60 (sexagesimal) representation that’s really short. For example, ‘1971-06-29’ becomes ‘94’, and ‘2010-05-26’ becomes ‘45v’.

As described in the interview, this value is used in conjunction with some other bits to create a reversible short URL – meaning that anyone following the algorithm described in that post should be able to derive the URL from the shortlink, and not be dependent on a particular service to resolve them.

This code is pretty complete and converts from DateTime to days-since-epoch, ordinal dates (YYYY-DDD, see the readme), and sexagesimal days.

---

Update

I’ve expanded the code and moved it to a new project name. I’ve implemented a URL shortener called TinWhistle (roughly based on Tantek’s Whistle) that uses NewBase60, and of which NewBase60 is now a sub-component.