Git made simple and fast

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Mascote do LinuxPro diante de um quadro com o diagrama de branch e merge do Git, ao lado do losango do projeto

Note (2026): the workflow below remains the everyday routine. The package is now git (not git-core), the default branch is usually main and the modern SSH key is Ed25519. The history — BitKeeper, the ten days of 2005, Junio Hamano, Git 2.55 — is in The history of Git.

A short cheatsheet: install, configure, clone, commit, push. No object theory. If you've never used Git, these commands handle 90% of cases.

Content hide
1 Install
2 Name, email and default branch
3 SSH key
4 New repository or clone
5 Add, commit, status
6 Branch: switch, not just checkout
7 Remote and push
8 A day's workflow
9 Video: Git Made Simple (LinuxTips)
10 More

Install

Debian/Ubuntu and derivatives:

sudo apt update
sudo apt install git
git --version

In 2026 the package is git. The old name git-core was a metapackage; don't look for it.

Name, email and default branch

git config --global user.name "Seu Nome"
git config --global user.email seu@email.com
git config --global init.defaultBranch main
git config --global pull.rebase false

user.name and user.email go into every commit. Without them Git complains. The industry's default branch stopped being master around 2020; main is what GitHub, GitLab and Git itself use for a new repository.

SSH key

Ed25519, not RSA 4096 — smaller and the current default. Details of the passwordless workflow: Passwordless SSH.

ssh-keygen -t ed25519 -C "seu@email.com"
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519
cat ~/.ssh/id_ed25519.pub

Paste the public key into GitHub/GitLab → Settings → SSH keys. Test:

ssh -T git@github.com

New repository or clone

mkdir projeto && cd projeto
git init
# ou, o caso comum:
git clone git@github.com:usuario/projeto.git
cd projeto

Add, commit, status

git status
git add arquivo.txt          # ou: git add -A
git commit -m "mensagem curta no imperativo"
git log --oneline -5

The commit stays in the local repository. It isn't on GitHub yet.

Branch: switch, not just checkout

git switch -c feature/login    # cria e entra
git switch main                # volta
git merge feature/login
git branch -d feature/login

git switch and git restore (undo file changes) have existed since Git 2.23 (2019) and separate the tasks that checkout used to combine. checkout still works; for new code, use the two new commands.

git restore arquivo.txt           # descarta mudança no working tree
git restore --staged arquivo.txt  # tira do index, mantém o arquivo

Remote and push

git remote add origin git@github.com:usuario/projeto.git
git push -u origin main

Next time: git push and git pull. The -u records the upstream. If the remote still uses master, change the branch name — don't invent main on a remote that doesn't have it.

git branch -M main    # só se você está migrando um repo antigo

A day's workflow

git pull
git switch -c fix/typo
# edita
git add -A
git commit -m "Corrige typo no README"
git push -u origin fix/typo
# abre o pull request no GitHub/GitLab
git switch main

Video: Git Made Simple (LinuxTips)

Jeferson Fernando's LinuxTips recorded “Descomplicando o GIT” — still the best Portuguese-language walkthrough of the workflow. The history (BitKeeper, the ten days, Git 2.55) is in the new post.

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