Unix wildcard selectors? (Asterisks)

Question

In Ryan Bates\' Railscast about git, his .gitignore file contains the following line:

tmp/**/*

What is the purpose of using the double

Answer 1

From http://blog.privateergroup.com/2010/03/gitignore-file-for-android-development/:

(kwoods)

"The double asterisk (**) is not a git thing per say, it’s really a linux / Mac shell thing.

It would match on everything including any sub folders that had been created.

You can see the effect in the shell like so:

# ls ./tmp/* = should show you the contents of ./tmp (files and folders)
# ls ./tmp/** = same as above, but it would also go into each sub-folder and show the contents there as well."