I've been idly looking at a few used vehicle models for the purpose of towing a glider (and glider trailer, obviously). Recently I've been checking out Toyota 4runners and Jeep Cherokees. A few weeks ago it was Nissan Pathfinders. Trying to gauge availability and pricing is a tricky business and one that I really didn't want to spent a lot of time on.
Since the used car ads on craigslist are quite active, I figured that was a good place to look. The trouble is that in the South Bay, East Bay, and Peninsula listings, they go by pretty quickly. I don't have time to track all that.
So I wrote a script that uses the RSS feeds. This is both good and bad.
The good points:
- I can run it from cron every 20-30 minutes and get e-mail.
- It's very lightweight.
- It took 5 minutes to write and another 5 to test and tweak.
On the negative side:
- Some false positives. People aren't always sure how to represent, say, a Toyota 4runner. Should it be 4-runner, 4runner, 4 runner, four runner, or something else? So I have to be a little more liberal in the regex I use. And sometimes they're selling a 4 runner service manual or something.
- There's currently no logic to notice that I've already seen a particular listing before, so I see duplicates sometimes.
- Craigslist, for some stupid reason, strips prices from the titles in their RSS feeds. So I have to look at every listing by hand. Or I may have to automate the process--fetch every page that looks interesting and try to find the price.
That last one really pisses me off, but it's a free service, so I can't complain too much I guess. All in all the script has saved me a couple hours of time so far.
What's that? You'd like the code? Oh, okay. I suppose I can share: cl-carfind.pl (921 bytes)
Share and enjoy. But don't mis-use it.
Posted by jzawodn at January 17, 2004 07:52 PM