I wrote this module as an example of both using closures and using
File::Find. Students are always asking me what closures are good for,
and here's some examples. The functions mostly stand alone (i.e. they
don't need the rest of the module), so rather than creating a
dependency in your code, just lift the parts you want).
Submitted by: Gea-Suan Lin <gslin at gslin.org>