I don’t know about you, but it’s common for me to switch between branches in Git. Â After all, that’s one of the main advantages of using Git — the incredible ease with which you can create and merge branches.
Just a few minutes ago, I was in the “adwords” branch of an application I’m working on. Â I wanted to go back to “master”, make sure that I hadn’t missed any commits from the central repository, and then go back to “adwords”. Â If there were any commits in “master” that I was missing in “adwords”, I figured that I would just rebase from “master” to “adwords”.
So I did a “git checkout master”, and found that I was up to date with the central Git server. For reasons that I can’t explain, I then decided to try something out: Instead of returning to the previous branch with “git checkout adwords”, I instead typed
git checkout -
(That’s a minus sign after the word “checkout.”)
Sure enough, I returned to the “adwords” branch!
Now, there is a fair amount of logic to this: In the Unix shell, you can typically return to the previous directory with “cd -“, which has proven to be quite useful over the years. Â In Git, of course, branches are just aliases to commits. Â So “git checkout -” is returning you to the previous branch, but it’s really just taking you back to whatever the last commit was that you worked on.
I just checked the Git documentation (“git checkout –help”), and it seems that this is a special case of a more generalizable command structure:
As a special case, the "@{-N}" syntax for the N-th last branch/commit checks out
branches (instead of detaching). You may also specify - which is synonymous
with "@{-1}".
I can’t imagine wanting to tell Git to return to the 5th-most-recent branch that I worked on, so this generalized formula seems a bit much to me.
I predict that this trick will save me precious seconds every day, all of which I squandered in writing this blog post. Â But I do think that this is a super-cool trick and feature, and demonstrates once again how clever and useful Git is.