The author 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).

WWW: https://metacpan.org/release/File-Find-Closures