mod_cache exporter

[drzraf]

Which are interesting Apache metrics too.
I wrote such an exporter for Munin (GPLv2), but contribution under MIT is a bit less appealing.

But basically, it's : htcacheclean -a -p /cache/path | egrep -o "<regexp-of-choice-N>" | sort | uniq --count
for the N regexps the user is interested in.