use older version of a file with git

Question

Until now I've did some basic operations with git, and in this real working scenario, I need to have access to an older version of a specified file. My question is how to transform a previous commit version in a new branch. Is it possible? How?

Answer 1

If you want to create a new branch at a arbitrary commit and check it out, do:

git checkout -b name_of_your_new_branch <sha1 of the commit>

Answer 2

If you just wan the older version of a file, you can do:

git checkout <commit> -- file