Are you talking about internal links to redirect pages? Double redirects? I'm a little confused.
Oh, I understand. Yeah, a bot can do that. The best way to do it would be to have the bot add a template like (broken link) next to a broken external link, which would link to and add the page to a category called "Pages with broken external links."
that would be a great thing. Then we could remove the links or try to find other cites.
try: urllib2.urlopen(url) except urllib2.HTTPError, err: if err.code == 404 or err.code == 400:
I hope you know Python.
Basically the Python URL module can raise HTML error codes, and the ones we're looking for are 404 (Not Found) and 400 (Bad Request).