Getting Git, and Telling It Who You Are

Check first — you may already have it. macOS ships a Git, and most Linux distributions install one by default.

$ git --version

Anything from 2.30 onwards is fine for everything in this track. If the command is not found, pick your system:

# macOS — Homebrew, and the version is newer than Apple's$ brew install git # Windows — the installer also gives you Git Bash, which you want$ winget install --id Git.Git -e # Debian or Ubuntu$ sudo apt update && sudo apt install git # Fedora$ sudo dnf install git

Git records an author on every commit, and it takes that from your config. Set it once, per machine, before you do anything else.

$ git config --global user.name "Your Name"$ git config --global user.email "[email protected]"

The name is what appears in git log and on every GitHub commit page. Use the name you would want a stranger reading your code to see.

The email is more consequential than it looks: GitHub matches commits to accounts by email address. Commit with an address GitHub does not know about and your commits appear on the site with a grey silhouette instead of your avatar, and they do not count towards your contribution graph. Nothing warns you.

Git's historical default branch name was master. Since 2020 the industry standard — and GitHub's default for new repositories — is main. Git itself still defaults to the old name unless you tell it otherwise, which produces a genuinely annoying mismatch on your very first push.

$ git config --global init.defaultBranch main

Two more settings that are worth the thirty seconds. Git opens an editor when a commit message needs more than one line, and its default on many systems is vim — which is a fine editor and a confusing surprise if you have never met it and cannot work out how to quit.

# Use VS Code, and wait for the window to close$ git config --global core.editor "code --wait" # Or nano, which tells you its own keys at the bottom of the screen$ git config --global core.editor nano

Windows ends a line of text with two invisible characters, carriage return and line feed. macOS and Linux use one, line feed. Git compares files line by line and treats those invisible characters as part of the line.

So on a mixed team, somebody opens a file, saves it without typing anything, and Git reports every single line as changed. The diff is unreadable and the pull request is useless.

# On Windows$ git config --global core.autocrlf true # On macOS or Linux$ git config --global core.autocrlf input

On a shared project the better answer is a .gitattributes file committed to the repository, which sets this for everybody regardless of what each person configured. One line covers the common case:

* text=auto

Every setting can be written in three places, and Git reads them in order with the most specific winning.

1. 1

   System — /etc/gitconfig

   Every user on the machine. Set with --system, usually by whoever installed Git. You will rarely touch it.

2. 2

   Global — ~/.gitconfig

   Your user account, across every repository. Set with --global. This is where the four settings above belong.

3. 3

   Local — .git/config in the repository

   This project only. No flag needed. This is how you commit to a work project with a work email and a personal one with a personal email.

When something behaves oddly and you cannot see why, ask Git where a setting came from. The answer includes the file, which is usually the whole explanation.

# Everything, with the file each value came from$ git config --list --show-origin # One setting, and where it was defined$ git config --show-origin user.email # Override it for this repository only$ git config user.email "[email protected]"