Git Cheat Sheet

For a while now, I’ve had a gradually-expanding note with various git commands that I’ve been using as a cheat sheet for git tasks that I do not do often, but regularly enough to write them down.

I figure putting them here will not only make them (slightly) easier to get to every time, but may also help other folks out.

So here they are! Keep in mind that this is just a quick (and intentionally incomplete) cheat sheet – if you are learning git for the first time, you’re better off looking elsewhere this is a good place to start.

General

Delete a file from the repo (opposite of ‘git add’):

git rm filename

revert a file to the current committed version:

git checkout -- filename

cache credentials when using https (seconds):

git config credential.helper 'cache --timeout=300'

clear cached credentials:

git credential-cache exit

ignore changes to a versioned file:

git update-index --assume-unchanged <file>

stop ignoring those changes:

git update-index --no-assume-unchanged <file>

change commit message of last commit:

git commit --amend -m "New commit message"

Branches

See all branches, including remote branches:

git branch -a

Pull a branch from a remote (“origin” here) and track it (this is tested and works with git 1.7.2.3 and higher)

git fetch --all
git checkout -b branch_name origin/branch_name

push a new local branch to origin:

git push -u origin branch-name

create a new branch:

git checkout -b new_branch

merge changes from branch hotfix into master:

git checkout master
git merge hotfix

delete the local branch:

git branch -d hotfix

track a remote branch:

git branch --set-upstream krystof_plots origin/krystof_plots

Forks

Add upstream remote:

git remote add upstream git@github.com:krystofl/krystof-utils.git

sync a fork (https://help.github.com/articles/syncing-a-fork):

git fetch upstream
git checkout master
git merge upstream/master

Reset a fork to whatever is on upstream:

git fetch upstream
git checkout master
git reset --hard upstream/master
git push origin master --force

Submodules

Add a git repo as a submodule:

git submodule add https://github.com/krystofl/krystof-utils.git

To make the submodule track a the master branch: open .gitmodules, and add a line to the submodule info:

branch = master

Move a submodule:

git mv path/to/old/submod path/to/new/submod

Remove a submodule (works most of the time):

git rm path/to/submodule

If the above doesn’t work, see this StackOverflow answer.

Squashing Commits

Squashing is helpful to keep the git history clean and manageable. For example, even if during development it took several commits on a feature branch to develop and test a new feature, it’s nice if once that feature is ready to be merged into the production branch it showed up as a single commit.

To do that, you can “squash” multiple commits together.

IMPORTANT: don’t do this if someone else might be using the commits you’d like to squash. If you do, they’re gonna have a bad time.

The easiest way to do this is when merging into another branch: git merge --squash

If you’d like to do it on the branch you’re on, you can do an interactive rebase like so:

git log to see the commit history

Figure out which commits you’d like to squash, and get the hash of the last commit you want to leave untouched in history. Let’s call it <that hash>.

git rebase -i <that hash>

That will bring up an editor. Leave pick for the commit you want to keep, and put s or squash in front of each commit you want to squash.

Be very careful not to delete any lines - those changes would be lost if you do delete them.

Save and close the editor. A new one will pop up to enter the commit message for the new combination commit. Do that.

Push your changes.

If you had already pushed these commits to a remote, a subsequent git push will be rejected. If you are sure that no else could be using these commits, you can git push -f origin BRANCH_NAME.

Rebase a merge request to top of tree (updating its base branch)

Based on this post.

Update base branch:

git fetch origin
git checkout BASE_BRANCH_NAME
git pull

Return to the issue branch and run the rebase command:

git checkout ISSUE_BRANCH_NAME
git rebase BASE_BRANCH_NAME

If the command works, you are done. If you see error messages in the merge, fix them :)

Push the changes:

git push -f origin ISSUE_BRANCH_NAME

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