This is a common request, i recommend starting off by reading merlyn's column for finding bad links. This is old code, be sure and read his next two improvements at col 14 and col 27. Then check out CPAN for modules like HTML::LinkExtor and HTML::SimpleLinkExtor.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)