Git Reference

Basics

Configure Git

git config --global user.name "Your Name" - set user name
git config --global user.email "user@domain.com" - set email
cd /path/to/repository - set directory path
git config --global core.editor /path/to/editor - set default editor
git config --global color.ui auto - turn on colors when possible

Create Repository for New Project

mkdir some-repository
cd some-repository
git init

Create Repository for Existing Project

cd /path/to/some/directory
git init

Clone Repository

git clone https://github.com/username/repo.git
git clone git://github.com/username/repo.git
git clone git://github.com/username/repo.git cloned-repo - clone to specific path
git clone --depth 50 some-repository - shallow clone with last 50 commits

Stage Files

git add . - add all files
git add -A or git add --all - add all files not explicitly ignored
git add -u or git add --update - add changed tracked files, does not add new files
git add myfile.* - add all files beginning with “myfile.”
git add -p or git add --patch - specifically choose which changes to commit, select ‘y’ or ‘n’ for each change
git does not track empty directories (as of v1.7) but adding an empty dot file will force tracking (i.e. “.include_in_git”)

Check Status and Commit Changes

git status
git commit -m "initial commit"

Ignore Files

add files to .gitignore: i.e. cache, *.RData
git config --global core.excludesfile ~/.gitignore - set up global excludes file in .gitignore in home directory

Undo Changes

git reset HEAD -- myfile.R - unstage myfile.R
git checkout -- myfile.R - undo uncommitted changes to myfile.R

Share Changes

git fetch reponame - get changes from remote repository
git pull reponame - pull from remote repository
git pull origin - pull and rebase local changes on top of remote changes
git pull --rebase origin remotebranch
git push remotename branchname - push changes to remote repository

Create Branches

git branch somebranchname optionalcommitIDorTag - create branch
git checkout somebranchname - switch to branch
git checkout -b somebranchname - create and switch to branch
git branch --track newbranchname - default tracking for remote branches
git branch --no-track new branchname - turn tracking off

View Branches

git branch - view local branches
git branch -r - view remote branches
git branch -a - view all branches
git branch --merged - view merged branches in current branch
git branch --no-merged - view unmerged branches
git branch --contains somecommitID - view branches with some commitID

Merge Branches

git checkout master
git merge developmentbranch - merge new branch into master
git merge --no-commit developmentbranch - merge without commit
git merge --no-ff developmentbranch - force merge commit, no fast forward
git merge -m "custom commit message" developmentbranch - merge with custom commit message
git rebase master - update development branch with new master commits
git rebase commitIDorTag - update parent for development branch
git reset --hard ORIG_HEAD - undo a rebase
git branch -d mergedbranch - delete unused merged branch
git branch -D unmergedbranch - delete experimental unmerged branch

Tag Commits

git tag - list all tags, remote and local treated the same
git tag v1.0 - create tag on latest commit in current branch

View Log

git log - see reverse chronological list of commits
git log --oneline - see shortened commit ID and messages in one line
git log -5 - see last 5 commits
git log -1 -p HEAD - see changes in most recent commit
git log -- filename - see log for single file
git log --after="7 days" - see commits in last week
git log --grep="some regular expression" - view log entries with some string

View Changes

git diff - diff current working tree and staging area
git diff --stages - diff staged changes and repository
git diff HEAD - diff working tree and repository
git diff firstcommitIDorTag secondcommitIDorTag - diff two commits

Other Commands

git mv README.md README.txt or git mv README.md wiki/ - rename or move README file
git rm -- outdated.txt - remove file
git rm -r -- outdated/ - remove directory
git remote add branchname webURL - add new remote repository
git remote rm branchname - remove remote repository
git pull origin remotebranch:localbranch - pull remote branch into local branch
git push origin remotebranch:localbranch - push local branch into remote branch
git push origin :beta - delete remote branch called beta (replaces with empty branch)
git revert --no-edit commitID - revert commit with default revert commit message
git reset --soft HEAD^ - reset last commit and stage changes
git gc - run garbage collection by default removes orphans older than 2 weeks
git gc --prune="1 week" - remove loose objects older than 1 week

Miscellaneous

Working with Forks

Reset origin from original upstream repository to personal fork

git remote set-url origin https://github.com/username/myrepo.git

Add original upstream repository as another remote and merge upstream commits into fork

git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
git pull https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git BRANCH_NAME
git push origin master

Squash Commits

Example of squashing last 3 commits with message “squash commits”

git reset --soft HEAD~3 && git commit -m "squash commits"

Force push

git push -f

Untrack Changes

In a directory

This command will cause git to untrack your directory and all files under it without actually deleting them:

git rm -r --cached <your directory>

The -r option causes the removal of all files under your directory.
The --cached option causes the files to only be removed from git’s index, not your working copy. By default git rm would delete .

For a specific file

Use the following command:

git update-index --assume-unchanged FILE_NAME

To track the changes again use this command:

git update-index --no-assume-unchanged FILE_NAME

Merging Branch

After the merge, it’s safe to delete the branch:

git branch -d branch1

Additionally, git will warn you (and refuse to delete the branch) if it thinks you didn’t fully merge it yet. If you forcefully delete a branch (with git branch -D) which is not completely merged yet, you have to do some tricks to get the unmerged commits back though (see below).

There are some reasons to keep a branch around though. For example, if it’s a feature branch, you may want to be able to do bugfixes on that feature still inside that branch.

If you also want to delete the branch on a remote host, you can do:

git push origin :branch1

This will forcefully delete the branch on the remote (this will not affect already checked-out repositiories though and won’t prevent anyone with push access to re-push/create it).