How can I reset or revert a file to a specific revision?

Question

I have made some changes to a file which has been committed a few times as part of a group of files, but now want to reset/revert the changes on it back to a previous versio

Answer 1

Amusingly, git checkout foo will not work if the working copy is in a directory named foo; however, both git checkout HEAD foo and git checkout ./foo will:

$ pwd
/Users/aaron/Documents/work/foo
$ git checkout foo
D   foo
Already on "foo"
$ git checkout ./foo
$ git checkout HEAD foo