MHauge | Security Engineer

About

The Swiss Army Knife that is “git checkout”

The Git checkout command is deceptively powerful and is something I end up using every day to accomplish various tasks. Let’s begin by reading the definition:

Updates files in the working tree to match the version in the index or the specified tree. If no pathspec was given, git checkout will also update HEAD to set the specified branch as the current branch.

Why is it so powerful?

Most of the power in git checkout comes from the fact that it can act on branches as a whole, directories or single files. This flexibility can be leveraged to make it do more than just switching branches.

Most of the tips below build on each other, but I will list them separately in order to have this serve as a quick lookup.

Remove local changes to all files in your working tree

Any changes made to files in your working directory can be discarded by using:

git checkout .

The literal . (dot) here signifies to discard all changes in the working tree recursively.

Remove local changes to a single file in your working tree

Any changes made to a single file in your working tree can be discarded by using:

git checkout path/to/file

Remove local changes to a certain folder in your working tree:

Any changes made to files in a single directory in your working tree can be discarded by using:

git checkout path/to/dir

Restore a previous version of a file

You can also specify a branch, both remote and local to restore a given version of a file. Here we want to restore the file to the version it had on our upstream branch named “feature-branch”:

git checkout origin/feature-branch -- path/to/file

However, we can also select a local branch:

git checkout feature-branch -- path/to/file

Note that “feature-branch” does not have to match the branch you are currently on. I often find myself doing the following to restore a file to the version present at the main branch.:

git checkout origin/main -- path/to/file

This also works if you deleted a file in your current branch, but it exists on a different branch, both local and remote.

Restore a previous version of a directory

You can also specify a branch, both remote and local to restore a given version of a file

git checkout origin/feature-branch -- path/to/directory

Restore deleted files

This is actually just an extension of restoring a previous version, but I have seen several times that people will use the UI to navigate through commits, finding the file and copying the contents directly. Instead we can use the following:

git checkout path/to/deleted/file

You won’t get autocomplete for the filename if it was deleted on your current branch, and you want to restore it, but it will still work!

If the file was deleted in a previous commit, we can find the hash of that commit and use:

git checkout <commit-sha> -- path/to/file

As always, this also works for directories:

git checkout <commit-sha> -- path/to/directory