What does "pick" in Git's interactive rebase do?

Question

When I do git rebase --interactive, I have six basic commands: pick, reword, edit, squash, fixup and exec.

What does pick command do? Does it cherry-pick a commit or does it checkout it?

Answer 1

From the help article:

pick
pick simply means that the commit is included. Rearranging the order of the pick commands changes the order of the commits when the rebase is underway. If you choose not to include a commit, you should delete the entire line.

For completeness, here's the other commands as well:

reword
The reword command is similar to pick, but after you use it, the rebase process will pause and give you a chance to alter the commit message. Any changes made by the commit are not affected.
edit
If you choose to edit a commit, you'll be given the chance to amend the commit, meaning that you can add or change the commit entirely. You can also make more commits before you continue the rebase. This allows you to split a large commit into smaller ones, or, remove erroneous changes made in a commit.
squash
This command lets you combine two or more commits into a single commit. A commit is squashed into the commit above it. Git gives you the chance to write a new commit message describing both changes.
fixup
This is similar to squash, but the commit to be merged has its message discarded. The commit is simply merged into the commit above it, and the earlier commit's message is used to describe both changes.
exec
This lets you run arbitrary shell commands against a commit.

Answer 2

Picking a commit in an interactive rebase means that Git uses the changes made by the commit in question and commits them with the original metadata (message, author, date etc.). So a single pick looks much like a git cherry-pick.

On the contrary, pick does not take the state of the whole repo in the time of the commit like git checkout would do. Just the changes made by the commit.

Answer 3

According to experiments, the pick command in git's interactive rebase works the same way as git cherry-pick --ff. Which, according to the documentation, acts this way:

If the current HEAD is the same as the parent of the cherry-pick’ed commit, then a fast forward to this commit will be performed.

(see: https://git-scm.com/docs/git-cherry-pick )