Machine-specific Git config changes

Update (2018-03-28): if you have work and personal projects on the same machine, a better way to do this is to put all your work projects in one directory and use conditional configuration includes, introduced in Git 2.13.

I store my .gitconfig in Git, naturally. It contains this block:

[user]
        email = will@willthompson.co.uk
        name = Will Thompson

which is fine until I want to use a different email address for all commits on my work machine, without needing git config user.email in every working copy. In the past I’ve just made a local branch of the config, merging and cherry-picking as needed to keep in sync with the master version, but I noticed that Git reads four different config files, in this order, with later entries overriding earlier entries:

  1. /etc/gitconfig – system-wide stuff, doesn’t help on multi-user machines
  2. $XDG_CONFIG_HOME/git/config (aka ~/.config/git/config) – news to me!
  3. ~/.gitconfig
  4. $GIT_DIR/config – per-repo, irrelevant here

So here’s the trick: put the standard config file at ~/.config/git/config, and then override the email address in ~/.gitconfig:

[user]
        email = wjt@endlessm.com

Ta-dah! Machine-specific Git config overrides. The spanner in the works is that git config --global always updates ~/.gitconfig if it exists, but it’s a start.