A few months ago a table was added to the database to track external (URL) links; the primary driver for this was to make it easier for an automated script to find and cleanup spam attacks.

But it's also useful for tracking down obsolete URLs that need to be updated. (Presumably because somebody didn't read http://www.w3.org/Provider/Style/URI !) I've whipped up a quick special page extension to search this links table.

For instance, all these links are broken since SourceForge mysteriously changed their CVS server with no forwarding address in April; now we can track them down and fix them:

http://meta.wikimedia.org/wiki/Special:Linksearch/cvs.sourceforge.net

You can also specify a path prefix. For instance these PyWikipediaBot links just need to be updated to the new SourceForge URLs:

http://meta.wikimedia.org/wiki/Special:Linksearch/cvs.sourceforge.net/viewcv...

while these MediaWiki links should be pointed to our new Subversion repository:

http://meta.wikimedia.org/wiki/Special:Linksearch/cvs.sourceforge.net/viewcv...

Wildcards for subdomains work too:

http://meta.wikimedia.org/wiki/Special:Linksearch/*.wikisource.org

At the moment you can only search http:// links, not https://, ftp:// etc.

-- brion vibber (brion @ pobox.com)