Installing and Configuring Git

Installing git

Ubuntu, under WSL or on a Linux desktop, may already have git; if not, install it from the package manager:

me@linuxbox:~$ sudo apt update && sudo apt install git
me@linuxbox:~$ git --version
git version 2.43.0

Your version number depends on your distribution’s release; anything from the last few years teaches the same commands. (Git for Windows is a separate installation of the same program for Windows itself; under WSL, use the Linux one.)

Who you are

The first thing to do after installing git is set your name and email. Every commit you make records them as its author, permanently ¹:

me@linuxbox:~$ git config --global user.name "Your Name"
me@linuxbox:~$ git config --global user.email you@example.com

--global means “for every repository I use on this machine,” so you do it once ¹. Use the same email you’ll use on GitHub (module 4), so your commits link to your account. GitHub also offers a private “noreply” address if you’d rather not publish your real one.

Three more settings

Default branch name. A new repository starts with one branch. Git’s built-in default name is still master, and the documentation says it will change to main in Git 3.0; you choose with init.defaultBranch ². GitHub and most projects use main:

me@linuxbox:~$ git config --global init.defaultBranch main

Editor. When git needs a longer message from you, it opens an editor ¹. Pick the one you’re comfortable with:

me@linuxbox:~$ git config --global core.editor nano

(If you set EDITOR in your ~/.profile in the shell course, git uses that already.)

Line endings. Windows ends lines with two characters (carriage return and line feed, CRLF); Linux uses just a line feed (LF). Mixed endings make files look completely changed and break scripts. Pro Git’s advice is to set core.autocrlf to input on Linux, which turns any stray CRLF into LF when you commit and never adds CRLF; on Windows itself, the setting is true ¹:

me@linuxbox:~$ git config --global core.autocrlf input

Where settings live

Git reads settings from three levels, each overriding the one before ¹:

• System, /etc/gitconfig: for every user on the machine (git config --system).
• Global, ~/.gitconfig: for you, in all your repositories (git config --global).
• Local, .git/config inside one repository: just that repository (plain git config, run inside it).

To see everything and which file each setting came from ^{1 3}:

me@linuxbox:~$ git config --list --show-origin
file:/home/me/.gitconfig    user.name=Your Name
file:/home/me/.gitconfig    user.email=you@example.com
file:/home/me/.gitconfig    init.defaultbranch=main
...
me@linuxbox:~$ git config user.email          # just one setting

Your global settings are just a small text file; cat ~/.gitconfig shows it. Module 7 puts it in version control along with your other dotfiles.

Aliases

Aliases are shortcuts for longer git commands ¹:

me@linuxbox:~$ git config --global alias.st status
me@linuxbox:~$ git config --global alias.lg "log --oneline --graph --all"

Now git st is git status, and git lg draws your history as a compact graph, which you’ll use a lot once there are branches.

Your turn

So

Install git with apt, then set, once, with --global: user.name and user.email (on every commit), init.defaultBranch main, core.editor, and core.autocrlf input. Settings live at system, global, and local levels, each overriding the last, and git config --list --show-origin shows them all.