Install Git
sudo apt update
sudo apt install git
git --version
Initialize a new repository
mkdir my-git-repo
cd my-git-repo
git init
Configure Git
git config --global user.name "Name"
git config --global user.email "user@example.com"
Git Operations
echo "This is my first repository." > readme
git add README
git commit -m "This is my first commit!"
echo "A repository is a location where all the files of a particular project are stored." > readme
git diff README
git add README
git status
git commit -m "This is my second commit."
git log
Git for All Platforms
Configure tooling
Configure user information for all local repositories
$ git config --global user.name "[name]"
Sets the name you want attached to your commit transactions
$ git config --global user.email "[email address]"
Sets the email you want attached to your commit transactions
$ git config --global color.ui auto
Enables helpful colorization of command line output
Create repositories
A new repository can either be created locally, or an existing repository can be cloned. When a repository was initialized locally, you have to push it to GitHub afterwards.
$ git init
The git init command turns an existing directory into a new Git repository inside the folder you are running this command. After using the git init command, link the local repository to an empty GitHub repository using the following command:
$ git remote add origin [url]
Specifies the remote repository for your local repository. The url points to a repository on GitHub.
$ git clone [url]
Clone (download) a repository that already exists on GitHub, including all of the files, branches, and commits
Branches
Branches are an important part of working with Git. Any commits you make will be made on the branch you’re currently “checked out” to. Use git status to see which branch that is.
$ git branch [branch-name]
Creates a new branch
$ git checkout [branch-name]
Switches to the specified branch and updates the working directory
$ git merge [branch]
Combines the specified branch’s history into the current branch. This is usually done in pull requests, but is an important Git operation.
$ git branch -d [branch-name]
Deletes the specified branch
The .gitignore file
Sometimes it may be a good idea to exclude files from being tracked with Git. This is typically done in a special file named .gitignore. You can find helpful templates for .gitignore files at github.com/github/gitignore.
Make changes
Browse and inspect the evolution of project files
$ git log
Lists version history for the current branch
$ git log --follow [file]
Lists version history for a file, beyond renames (works only for a single file)
$ git diff [first-branch]...[second-branch]
Shows content differences between two branches
$ git show [commit]
Outputs metadata and content changes of the specified commit
$ git add [file]
Snapshots the file in preparation for versioning
$ git commit -m "[descriptive message]"
Records file snapshots permanently in version history
Synchronize changes
Synchronize your local repository with the remote repository on GitHub.com
$ git fetch
Downloads all history from the remote tracking branches
$ git merge
Combines remote tracking branches into current local branch
$ git push
Uploads all local branch commits to GitHub
$ git pull
Updates your current local working branch with all new commits from the corresponding remote branch on GitHub. git pull is a combination of git fetch and git merge
Redo commits
Erase mistakes and craft replacement history
$ git reset [commit]
Undoes all commits after [commit], preserving changes locally
$ git reset --hard [commit]
Discards all history and changes back to the specified commit
CAUTION! Changing history can have nasty side effects. If you need to change commits that exist on GitHub (the remote), proceed with caution. If you need help, reach out at github.community or contact support.
Deleting History
cat .git/config --> note the remote origin
rm -rf .git
git init
git add .
git commit -m "Initial commit"
git remote add origin <remote url>
git push -u --force origin master
Creating Repo locally and push to create remote
Git push using SSH
git push --set-upstream git@gitlab.example.com:namespace/nonexistent-project.git master
Git push using HTTPS
git push --set-upstream https://gitlab.example.com/namespace/nonexistent-project.git master
Glossary
- git: an open source, distributed version-control system
- GitHub: a platform for hosting and collaborating on Git repositories
- commit: a Git object, a snapshot of your entire repository compressed into a SHA
- branch: a lightweight movable pointer to a commit
- clone: a local version of a repository, including all commits and branches
- remote: a common repository on GitHub that all team members use to exchange their changes
- fork: a copy of a repository on GitHub owned by a different user
- pull request: a place to compare and discuss the differences introduced on a branch with reviews, comments, integrated tests, and more
- HEAD: representing your current working directory, the HEAD pointer can be moved to different branches, tags, or commits when using
git checkout
Source: https://training.github.com/downloads/github-git-cheat-sheet/
