Different author email addresses per git repository

Git v2.8 introduced a new configuration option called user.useconfigonly. This option prevents git from trying to guess your email address to use for the author metadata for a commit and forces you to have configured one.

This is great news because with a good workflow in place you can be sure you always have the correct email addresses on your commits.

Global Configuration

If user.useconfigonly is set to true, you will need to configure an email address. The simplest way is with this command:

git config --global user.name 'Steve Occhipinti'
git config --global user.email [email protected]

Which will result in a configuration like this saved in ~/.gitconfig:

[user]
  name = Steve Occhipinti
  email = [email protected]

This is great, but what if you want to work on personal projects and work projects on the same machine?

Per Repository Configuration

Instead of using the global config in the home directory, git will first look for a local configuration in ./.git/config. To set per repository configuration, all you have to do is cd to the repo and run the same commands but without the --global flag:

git config user.name 'Steve Occhipinti'
git config user.email [email protected]

Mixing Work And Personal

If you have a global configuration, all repositories will use that as a default unless you remember to set a per-repository config. If you don’t set a global config, git will normally guess what your email is and use that if its valid.

If you set the useconfigonly option and remove your global config, git will not allow you to make a commit until you’ve setup your user details and this will prevent accidentally using your work email address on a personal project or vice-versa.

However, I do leave my name configured globally as that is not going to change between repositories.

Visual Queues

Having that error appear when you haven’t setup an email address is great, but rather than waiting for me to make a mistake, I added an exclamation mark indicator to my shell prompt to remind me to set up the user details.

The basic idea is something like this:

local noauthor
git config user.email > /dev/null || noauthor="!"
export $PS1="$noauthor${PS1}"

Quicker Configuration

If this is something that I will have to do for every repo I create or clone, I want to it be pain free. Git makes it really easy to create new sub commands simply by putting a script named git-xxxx in the path, where xxxx is the sub command name.

I created a git-author script like this:

#!/bin/bash
set -e

email_list_file="$HOME/.config/git/author-emails"
has_pecorb=$(type pecorb > /dev/null 2>&1)

echo "Current author: $(git config user.name) <$(git config user.email)>"

if [ -f $email_list_file ] && $has_pecorb; then
  email=$(pecorb $email_list_file)
else
  echo -n "Enter a new email address: "
  read email
fi

git config user.email $email

Now when go to a repo and I see my ! indicator, all I have to do is run git author.

This allows me to put all my email addresses in a file and then select the one I want from a nice menu. Note, I’m using pecorb here which is a gem I wrote to generate selectable menus on the command line, but there are plenty of alternatives or you could just use read in bash and type it in (which my script falls back to).

My Bash Prompt

The prompt I use may not be the tidiest, but its available here.