I wrote a small site to search slackware packages containing a wanted file.
It do searches in official slackware repositories and some non official.
It is based on PACKAGES.TXT, so all repositories containing it can be used.
If a repository contain even the MANIFEST.bz2 file, then this tool can search packages from its content.
Results are cliccable link so to download the package directly.
Thanx all for reported repositories. Now are supported 40 repositories.
If you know other, report me, so I can add it.
I've added two search method useful for your script.
can report results in plain text/csv format.
can report results in xml format.
Both are in development but working mode.
Report me if you found a bug (or if you want add a field).
Sorry for my bad english,