Git and GitHub

Git is a version-control system that tracks changes to your files, and GitHub is a website for hosting Git repositories. Together they let you save snapshots of your work and share it.

The best way to be sure you’re set with Git and GitHub is to fill out and follow the form here.

Installing Git

On DataHub, Git is already installed. To install it on your own machine:

Open Terminal and run:

git --version

If Git is missing, macOS will offer to install the developer tools. Accept and let it finish, then run the command again to confirm.

Install Git for Windows, which also provides Git Bash. Open Git Bash and confirm with:

git --version

One-time setup

Tell Git who you are:

git config --global user.name "Your Name"
git config --global user.email "you@berkeley.edu"

The core workflow

Step Command Meaning
Clone git clone <url> Copy a repository to your machine
Stage git add <file> Mark changes to be saved
Commit git commit -m "message" Save a snapshot with a note
Push git push Upload commits to GitHub
Pull git pull Download others’ commits

Check the state of your repository at any time with:

git status

Github

Go to https://github.com/ to set up a free account. Whichever email address you use to create your account, it should agree with same as the email you used in git config --global user.email "you@berkeley.edu". If you expect to not use Github after leaving Berkeley, then just use your Berkeley email. If you think you might use it after graduation, use your personal email.

Authenticating with a personal access token

GitHub will not accept your account password from the command line. Instead you use a personal access token (PAT): a long string of characters that acts as a password for Git. You create it in the browser, then paste it into the terminal whenever Git asks for a password.

1. Create the token in your browser

  1. Sign in at https://github.com/ and go to https://github.com/settings/tokens?type=beta (Settings → Developer settings → Personal access tokens → Fine-grained tokens).
  2. Click Generate new token.
  3. Fill in the form:
    • Token name: something you’ll recognize, like stat133-positron.
    • Expiration: pick a date after the end of the semester.
    • Repository access: All repositories.
    • Permissions: under Repository permissions, set Contents to Read and write. Leave everything else alone.
  4. Click Generate token, then copy the token that appears.
Warning

The token is shown only once. Copy it now. If you lose it, delete it on GitHub and generate a new one — that’s normal and costs you nothing.

2. Paste it at the prompt

Do something that talks to GitHub, such as cloning one of your repositories or running git push from inside one. In Positron’s Terminal pane:

git clone https://github.com/USERNAME/REPO.git

Git will prompt you twice:

Username for 'https://github.com': your-github-username
Password for 'https://github.com': <paste your token here>

Paste the token, not your GitHub password. Nothing will appear on screen as you paste — that’s expected. Press Return.

That’s it. Git will ask you to paste the token again for each push or clone until the token expires — for a handful of assignments that’s a minor annoyance, not a problem.

TipDon’t want to paste it every time?

You can ask Git to remember the token so you’re only prompted once:

  • macOS: git config --global credential.helper osxkeychain
  • Windows: git config --global credential.helper manager

Run the command once, then paste the token at the next prompt. Git stores it and won’t ask again.

Tips

  • Commit early and often, with short but descriptive messages.
  • git status is your friend — run it whenever you’re unsure what’s going on.
  • Treat your PAT like a password: don’t paste it into a script, a .qmd file, or a repository.