Programster's Blog

Tutorials focusing on Linux, programming, and open-source

Git Cheatsheet

Below is a cheatsheet for Git so we don't become like the guys in this comic:

Image courtesy of xkcd

Related Posts

Table of Contents

Basics  

Installation (Linux)  

sudo apt update && sudo apt install git -y

Quickly Initialize Code In Git  

If you have a bunch of code that is not currently under git/version control, then using these commands inside the directory will set up git AND add all the current files to it:

git init
git add .
git commit

Check if Out of Date  

git remote update $REMOTE_NAME
git status

If you are out of date, then run the following:

git pull $REMOTE_NAME

This only fetches and pulls the current branch, and does not try to do anything with any of the other branches.

Alternatively, one can manually run the following two steps, that pull performs:

git fetch $REMOTE_NAME $BRANCH_NAME
git merge $REMOTE_NAME/$BRANCH_NAME

View Diff  

If you want to see the differences that haven't been staged yet against the "base", use:

git diff

If you wish to see the differences that you have staged for committing, then use:

git diff --staged

Renaming Files  

Although git can detect renames, using the mv command on a file, it's probably best just to think of this as deleting a file and creating a new one.

  • If substantial changes are made to the file before the mv, it may not be picked up as a rename
  • Due to the fact that detecting renames is expensive, it is turned off by default and the -M
  • switch has to be given to git log if you do want to see renaming.

Restore A Deleted File  

If you have various outstanding changes, and want to restore/revert a file that you had deleted at some point and have not committed yet, run the command below to get it back in its last committed form:

git checkout $FILENAME

Unstage A Deletion  

The previous example was for when you had deleted a file locally but had not committed yet. If you have a staged deletion of a file that you wish to restore (such as after performing a merge with --no-commit), then you would need to do the following:

git reset -- $FILENAME
git checkout -- $FILENAME

Revert a File  

If you want to revert any staged changes to a file, you can revert them with the same command we used to restore a deleted file:

git checkout $FILENAME

... there is also the option to use:

Unstage A File  

If you wish to just unstage a file that may or may not already exist in the repo, and you wish to keep the local changes to that file locally, then use:

git reset HEAD $FILENAME

You may think the command below is an "alias" of the one above for unstaging a file. If the file hasn't been committed, then it would unstage the file and keep it locally. However, if it does already exist in the repo, it would actually stage it for removal!

git rm --cached myFile.txt

If you run the command above on a file that already exists in the repo, you will be staging it to be removed!

View History  

git log

By default this will not wrap messages in your terminal. If you want to do this, use

git log | less

Also, if you want a visual representation of your branches/history the following command is extremely useful:

git log --oneline \
  --abbrev-commit \
  --all \
  --graph \
  --decorate \
  --color

It's an extremely good idea to use an alias for the command above, such as gg.

Understanding Git  

Git Data Transport Command Diagram  

Repo Types  

There are two types of repositories:

  • Bare - Nobody directly uses the repo, but is used for a centralized area for multiple developers to push and pull from. (Like your SVN repo).

  • Shared - This is a "normal" repo that you have set up yourself, and users within the same group can 'pull' (update your code from) or 'push' (apply changes) to it. Likewise you can pull from/push to other peoples shared repos.

These types are indicated with --bare and --shared respectively on the git init command. When not specified, git init will create a shared repository. Click here if you need more info.

Fetching  

The git fetch command downloads commits, files, and refs from a remote repository into your local repo. Fetching is what you do when you want to see what everybody else has been working on. More info from Bitbucket.

SVN Similarities  

Similar Commands To SVN  

These commands just need to be prepended with git, instead of svn:

  • commit
  • add
  • diff
  • log
  • status

Differences  

  • mv instead of move
  • rm instead of delete
  • init instead of svnadmin create

List Branches  

List Local Branches  

The command below will list local branches:

git branch

List Local And Remote Branches

This command will list all local branches, and all remote branches that your git repository currently knows about.

git branch -a

You may need to update your remote or fetch from all of your remotes.

Creating A Branch  

Create A Local Branch  

The following command will simply create a new local branch from your current branch. It does not try to perform any "smarts" to do with remote branches and tracking.

git branch $NEW_BRANCH_NAME

This does not automatically switch you to that branch.

This will create a branch from whatever branch you are currently in rather than always from master or main.

Create A Local Branch And Switch To It (Ignoring Remote)  

The command below will create a local branch and switch to it. If the branch already exists on the remote with the same name, this branch will have been created without being set to track it. If you were to wish to push to that remote, you would need to set the branch upstream, which can also be done within the push command.

git checkout -b $NEW_BRANCH_NAME

Create A Local Branch That Tracks Remote Branch of Same Name  

If a branch exists on your repository that you wish to work on, then you want to use the following code to create a local branch of the same name that will track the remote one.

git checkout --track $REMOTE/$BRANCH

If you have just one remote, then you don't need to specify the remote and can just do the following. Git will automatically figure things out as mentioned here.)

git checkout $NAME_OF_REMOTE_BRANCH_THAT_DOESNT_EXIST_LOCALLY

Create A Local Branch That Tracks Specified Remote And With Different Name  

This command is particularly useful when one is juggling multiple remotes. E.g. a GitLab and a GitHub, and they both have branches with the same name, but with two different histories. In such a case, it is useful to specify the remote, and use a different name for the branch. E.g. github-develop and gitlab-develop for the develop branch on either source.

git checkout \
  -b $NEW_LOCAL_BRANCH_NAME \
  $REMOTE_NAME/$REMOTE_BRANCH_NAME

E.g.

git checkout -b github-develop github/develop

Checkout a Remote Branch With Different Name  

The command below will allow you to checkout a remote branch and give it a different name, but I recommend you just use the previous command for creating a local branch that mirrors remote instead.

git checkout \
  -b $LOCAL_BRANCH_NAME \
  origin/$REMOTE_BRANCH_NAME

Branch Switching  

Git Checkout  

You can use the git checkout command to switch to a different branch that you already have locally. If the branch doesn't already exist locally, and your default remote has a branch with the same name, git will automatically create a local branch that tracks the remote branch, and switch to it.

git checkout $OTHER_BRANCH

Branch Pushing  

Push a Local Branch To Remote and Set to Track  

Perform this command if you created a local branch that doesn't exist on remote and you want to create it on the remote with the same name

git push --set-upstream $REMOTE $LOCAL_BRANCH_NAME

e.g.

git push --set-upstream origin myBranch

The shorthand for --set-upstream is -u.

Push Local Branch To Existing Remote Branch With A Different Name  

Use this command to push a local branch to a remote branch with a different name This is particularly useful when one is working with branches that have mismatching names to remotes, and you may have had to unset the upstream earlier for some reason.

git push $REMOTE_NAME $LOCAL_BRANCH_NAME:$REMOTE_BRANCH_NAME

e.g.

git push github  github-main:main

Branch Deletion  

Delete a Remote branch  

git push $REMOTE_NAME --delete $BRANCH_NAME

For example:

git push origin --delete $BRANCH_NAME

Delete All Local Tracking Branches That Aren't On Remote  

git remote prune $REMOTE_NAME

Delete a Local branch  

git branch -d $BRANCH

If the branch has changes that haven't been merged, then you will need to use the following instead:

git branch -D $BRANCH

Upstream Management  

Set Upstream  

git branch --set-upstream-to=$REMOTE/$REMOTE_BRANCH $LOCAL_BRANCH

e.g.

git branch --set-upstream-to=origin/develop origin-develop

Unset Upstream  

Use the following command to unset the upstream of a branch by name.

git branch --unset-upstream $LOCAL_BRANCH

Alternatively, if you wish to unset the upstream of the current branch, then you can just do:

git branch --unset-upstream

Merging  

Basic Merging  

The command below will merge the specified branch into the current branch and automatically commit if successful:

git merge $BRANCH

If you wish to be able to review the changes before commiting the merge (and possibly make some last minute changes), then use:

git merge --no-commit --no-ff branchname

Cherry Picking  

If you are not ready to merge a whole branch, but need to grab some of the changes/commits, you want to use the cherry-pick command on each change that you desire. For example:

git cherry-pick 87bafa9

You may wish to do this multiple times and commit as a single commit. In such a case just make sure to use the --no-commit flag on each cherry-pick, and then manually commit when you are done.

git cherry-pick 87bafa9 --no-commit
git cherry-pick 52a08a4 --no-commit
git cherry-pick afa6635 --no-commit
git cherry-pick 1cb5f92 --no-commit
git commit

Resolving Conflicts  

The following command is your best friend:

git mergetool

You may wish to configure meld to act as your merge tool.

Also, you may wish to have 3 files checked out to act like SVN and manually do your diff/merging.

FILENAME="filename.txt"
git show :1:./$FILENAME > ./$FILENAME.base
git show :2:./$FILENAME > ./$FILENAME.working
git show :3:./$FILENAME > ./$FILENAME.remote

The above command gives you all the variations of the file, but usually I find that I just want the following:

FILENAME="filename.txt"
git show :2:./$FILENAME > ./$FILENAME.working
git show :3:./$FILENAME > ./$FILENAME.remote
rm $FILENAME

Tags  

Unlike SVN, git has a concept of tagging built-in. This means that when creating a release of a PHP package, you don't branch off into the /tags directory, but simply run:

git tag $NEW_TAG_NAME

If you want to see the tags/releases, run:

git tag

If you want to switch to a tag, execute:

git checkout $TAG_NAME

Tags do not get pushed to the remote repository automatically with commits. You need to manually run:

git push --tags

If you want to delete a local tag then use

git tag --delete $TAG_NAME

Deleting a tag does not result in it being pushed. To delete a remote tag, you need to specify it specifically:

git push --delete $REMOTE_NAME $TAG_NAME

If you want to create a tag, but want to give a specific description other than the log on the revision you are tagging, you can use the following:

git tag -a $TAG_NAME -m "[tag description/log]"

Remotes  

List Remotes  

git remote -v

Add a Remote  

The example below shows how to add an SSH-based remote.

git remote add --mirror=push [remote name] [user]@[hostname or IP]:[path to repo]
git remote add --mirror=fetch [remote name] [user]@[hostname or IP]:[path to repo]

e.g.

git remote add --mirror=push origin git@git.mydomain.org:/home/git/my-repo
git remote add --mirror=fetch origin git@git.mydomain.org:/home/git/my-repo

Note: You can specify just push or fetch if you only intend to perform one of those.

After adding a remote, one probably wants to run the following command to retrieve information about the remote branches etc:

git fetch $REMOTE_NAME

If you have to deal with multiple remotes having branches with the same name, then you may find your life easier by configuring git to not require local branch names to match the name of the remote.

git config push.default upstream

... now you can easily checkout a branch like so:

git checkout \
  -b remote-name-remote-branch-name \
  remote-name/remote-branch-name

... which will then be allowed to push without any commands requiring HEAD.

Rename Remote  

git remote rename $OLD $NEW

Change Remote's URL  

If you moved your remote repository, then you can just update the remote instead of adding the new location and removing the old one.

git remote set-url origin ssh://git@gitlab.mydomain.com:23825/user/project-name.git

Update Remote  

Use the following command to fetch information about branches/changes to a remote.

git remote update $REMOTE

You can also do the following to automatically prune any local branches that have been deleted from the remote:

git remote update $REMOTE --prune

Since git 1.8.5 we can configure git to automatically provide the --prune parameter if desired when fetching or pruning.

Fetch Remote  

The command below fetches all of the branches from the repository. This also downloads all of the required commits and files from the other repository.

git fetch $REMOTE_NAME

Fetch All Remotes  

The command below fetches all registered remotes and their branches.

git fetch --all

Remove Remote  

git remote remove $REMOTE_NAME

Alternatively, you can use:

git remote rm $REMOTE_NAME

Adjusting/Rewriting History  

Move Recent Commits To A Branch  

This has been moved into a dedicated post

Change Last Commit Author  

If you just wish to change the author on the previous commit, then do the following:

git commit \
  --amend \
  --author="Programster <me@programster.org>"

Edit Last Commit Message  

If you wish to change the last commit message you made, and you haven't pushed yet, then you can just use:

git commit --amend

Then just set the commit message to what you want.

Rebase Vs Merge  

When you want to update a branch from upstream (usually master), you have two options. Merge and rebase. Rebase can be confusing for newcomers coming from SVN, so I just wanted to provide this diagram of the difference.

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">
Rebase
[Not supported by viewer]
Merge
Merge

As you can see, the rebase will give you a much cleaner looking history. However, the diagram does not clearly convey the point that in a rebase, each point in the branch's history (purple points) will be considered a new commit after a rebase operation. This is why its okay to rebase your local branches, but it's not okay to rebase something that has gone public. Merging is perfectly okay for things that have been pushed publicly.

I found the section on git rebase from Atlassian most useful.

Configuration  

Global Configuration File Location  

Your global configuration file should be found at:

$HOME/.gitconfig

Command To Edit Global Configuration File  

One can use the following command to quickly open your global configuration file within your default editor, for editing. This way you don't need to locate the file and manually open it.

git config --edit --global

Ignore File Mode / Executable Bit  

If you wish to ignore changes to the executable bit on files, then run the following from inside your repository:

If you wish to do this globally, then do:

git config core.fileMode false
git config --global core.fileMode false

Use Meld for diffs  

Read about how to do it here.

Set Username/Author  

To globally set your default 'username' for commits across all projects run the following code:

git config --global user.name [username]

Note: This will be overriden by the 'local' scale if it exists. To set your username at a local scale, you can run the following command from inside your repo:

git config --local user.name [username]

Alternatively, you could edit the .git/config file directly.

Set Email  

git config --global user.email "email@example.com"

Enable Colour Coding!  

To enable the use of colour for things like diffs:

git config --global color.ui auto

It is possible to configure colour coding on only certain aspects, or even change the colours themselves, but that is beyond the scope of this tutorial.

Set Default Editor  

git config --global core.editor $EDITOR_NAME_HERE

Aliases  

Git allows you to set aliases. e.g.

git config --global alias.cp cherry-pick

This would allow you to run git cp instead of git cherry-pick. However this would likely cause confusion with the linux copy command which is also cp.

Configure Automatic Branch Pruning  

Since git 1.8.5 one can configure git to automatically prune when performing git fetch and hence pull commands by doing the following:

git config remote.*.prune true

If you wish to only perform automatic pruning on a particular remote, than you can specify it like so:

git config remote.$REMOTE_NAME.prune true

If you wish to always prune on git fetch (and thus affect git pull), one can do the following:

git config fetch.prune true

If you wish for this to be globally set across all repositories, then be sure to add the --global parameter like so:

git config --global fetch.prune true

This would change your global git configuration file at ~/.gitconfig to have:

[fetch]
    prune = true

Authentication  

It is important to note that the Git protocol does not support authentication. To restrict people's access to your codebase, you need to use the other tools at your disposal. E.g. Setting up an SSH account(s) for the other colleagues to access your repo on. This is unlike SVN, whereby for each Repo, you can configure specific username/password pairs which were used for the 'authors' in the logs.

Submodules  

Add Submodule To Project  

git submodule add https://github.com/programster/projectNameHere

Checkout All Submodules  

For a repo with submodules, we can pull all submodules using

git submodule update --init --recursive

This will add to, or create a .gitmodules file in your repository.

Update All Submodules  

git pull --recurse-submodules

.gitignore  

Gitignore Basics  

One can add a .gitignore file to a directory and specify files to ignore e.g.

ignore/this/path

Usually, I find that I want to ensure the folder is committed, but that everything in the folder is ignored, so I will add a .gitignore file to the folder like so:

*
!.gitignore

The ! tells gitignore to ignore that specific path from the ignores. (A double negative).

Ignore Everything But A Specific Directory  

In a niche-case where you want to ignore everything in a directory, except for everything under a specific subdirectory, you would do the following

*
!/desired-subdirectory/**/*

Misc  

Edit Branch Description  

You can edit a branch's description by running the following command. This is used by other commands such as format-patch, request-pull, and merge.

git branch --edit-description $BRANCH_NAME

Install RabbitVCS GUI (Ubuntu)  

sudo add-apt-repository ppa:rabbitvcs/ppa -y \
  && sudo apt-get update \
  && sudo apt-get install rabbitvcs-nautilus3

In Ubuntu 13, you may need to perform these extra steps.

References  

Last updated: 20th April 2022
First published: 16th August 2018