ack: Exclude specific directories from search via regex

With ack2, it seems you can't use holygeek's solution.

Here's how I'd do it using -v and -x:

ack -v -g 'test' | ack -x pattern

More generally, 'test' can be a regex for dirs to exclude

Use the undocumented option "--invert-file-match" (ack version on my system: 1.96):

$ ack pattern -G 'test|tests' --invert-file-match

Well, it is sort of documented:

$ ack --help|grep invert
-v, --invert-match    Invert match: select non-matching lines
--invert-file-match   Print/search handle files that do not match -g/-G.

It is not documented in its perldoc.