I am done looking this up online every time I think of doing this. This time I am writing the canonical (for me) guide on how to do this. My sincerest gratitude to the original author (Shirish Padalkar's post) whose guide I followed this time.

The premise is that we have multiple identities for various projects that we work on. Let's say I work as a consultant with two companies Frame and Clock, and this is how I organise my projects:

Projects
├── all-other-projects-go-here
├── clock
│   └── projects-for-Clock-stay-here
└── frame
    └── projects-for-Frame-stay-here

And these are the identities I need to be using in these projects:

• Projects for Frame: varun@frame.com
• Projects for Clock: varun@clock.com
• Everything else: varun@varunbarad.com

The way to solve this is to have three config files for git; a base/global config and then two additional files which are decided (based on the repo-root) whether to import or not.

# ~/.gitconfig-frame

[user]
    name = Varun Barad
    email = varun@frame.com

# ~/.gitconfig-clock

[user]
    name = Varun Barad
    email = varun@clock.com

The above are our files to set the appropriate identity. Now we need to tell our global gitconfig to import either of these two files when in the correct directory.

# ~/.gitconfig

[user]
    name = Varun Barad
    email = varun@varunbarad.com

[includeIf "gitdir:~/Projects/frame"]
    path: .gitconfig-frame

[includeIf "gitdir:~/Projects/clock"]
    path: .gitconfig-clock

And that's how it's done. That's all folks. Now wherever you create your repo, appropriate author information is applied based on where the repo was created.