Get started:
$ sudo gem install cheat
$ cheat strftime
A magnificent cheat sheet for Ruby's strftime method will be printed to your terminal.
To get some help on cheat itself:
$ cheat cheat
How meta.
Cheat sheets are basically wiki pages accessible from the command line. You can browse, add, or edit cheat sheets.
Try to keep them concise. For a style guide, check out the cheat cheat sheet. To access a cheat sheet, simply pass the program the desired sheet's name:
$ cheat <sheet name>