How-to revert a locally modified file

Hello,

I searched the net and couldn't find the answer to how to revert a
file to its "pre-modified" state.

I did see in the 0.99.7 To Do:

* Perhaps a tool to revert a single file to pre-modification
state? git-cat-file blob `git-ls-files | grep foo` >foo or
git-cat-file blob `git-ls-tree HEAD foo` >foo? What should
the command be called? git-revert is taken so is
git-checkout.

Did such a command come to be?

Thanks,