Your Schwartz Factor on your CPAN Page

November 12th, 2010
Schwartz factorCPANGreaseMonkeyHTML::Treeuserscript.org

Your Schwartz Factor on your CPAN Page

The Schwartz

The Schwartz factor of a CPAN author is the ratio of the number distributions of that author over the number of tarballs sitting in his CPAN directory. A low number indicates that it’s probably time for this author to do some clean-up (without fearing to lose the old tarballs, as they will always be available via the BackPAN, natch).

As such, I wanted to include a periodic check of my Schwartz factor to my monitoring system. Coming up with a script to extract the information from my CPAN home directory was simple enough:

schwartz_factor.pl

This is not exactly the most robust code I ever written — the parsing of the page should be left to HTML::Tree, really — but it’s doing what it’s supposed to do. Not, though, that depending on which mirror site you’ll hit, the factor may vary a little bit.

But then I thought, why keep the fun offline? So I imported the logic into a GreaseMonkey script and I now have the Schwartz factor of CPAN authors added to their CPAN pages:

Schwartz factor on CPAN author page

The script will not work for authors who dropped an index.html in their home directory, or if they use sub-directories, but I expect that they should be more the exception than the rule.

The GreaseMonkey script is available on the userscripts.org site, and on GitHub.