(hello

‘world)

A trivial bug in cl-audioscrobbler

So as I’m learning Common Lisp, as I usually do in a new language, I decide to write an IRC bot. It has been quite an interesting experience. Having had the general framework figured out I started to make it actually do some things, google searches, quotes, etc…

I also recently set up a last.fm account and had nothing better to do on New Year’s Eve, so I thought it would be nifty if I had my bot interact with last.fm in some way, and I found a handy library to do just that, cl-audioscrobbler.

But it always set the time the song played to 6 hours before I actually played it. It was easy to figure out what was going wrong, given I’m in CST, or UTC-6. Last.fm’s API specifies: “UTC date/time in YYYY-MM-DD hh:mm:ss format”. cl-audioscrobbler was sending my *local* time.

So I found the bit of code that figures out what time it is in src/tools.lisp, and naively tried to simply add 6 hours to whatever it produced. Naturally, that didn’t work out so well, and I wound up with something that kinda sorta worked but was hugely complicated and ugly. Then I found the un-braindead way to do it.

Change (get-decoded-time) to (decode-universal-time (get-universal-time) 0)

It’s not much, and chances are cl-audioscrobbler’s author has already found and fixed this (it was obvious looking at the sources that 1.2 support was already well underway), but I sent him a quick note about it anyway.

But it was the first bug in Lisp I’ve ever fixed that wasn’t in my own code, so I’m still pretty happy about it.

—–

Update: As of 2008/01/08 this is fixed with the 0.3.1 release. Thanks to Nicolas Lamirault for accepting my first ever Lisp patch =)

January 3, 2008 - Posted by | cl-audioscrobbler, Common Lisp, Last.FM

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