Based on tenderlove’s which tenderlovemaking.com/2011/12/05/profiling-rails-startup-with-dtrace/
Base Use: > require ‘rwhich/file’ > File.which ‘ls’
> “/bin/ls”¶ ↑
> File.which ‘hahahahahah’ assuming you don’t have a hahahahahah executable in ENV
> nil¶ ↑
Other Use: > require ‘rwhich’ > Class Foo
extend RWhich end
> Foo.which ‘ls’
> “/bin/ls”¶ ↑
> Class Bar
include RWhich end
> bar = Bar.new > bar.which ‘ls’