If you are like me and you organize your projects in different folders like ~/Projects/MyCompany for work-related projects and ~/Projects/Personal for side projects, and you want to be able to configure git email based on the directory, instead of configuring it for each folder, then it can be achieved using conditional includes in git config.
Add entries in the following format in your ~/.gitconfig. Customize the paths as per your requirements:
# ~/.gitconfig
[includeIf "gitdir:~/Projects/MyCompany/"]
path = ~/Projects/MyCompany/.gitconfig
[includeIf "gitdir:~/Projects/Personal/"]
path = ~/Projects/Personal/.gitconfig
And update the individual configs:
# ~/Projects/MyCompany/.gitconfig
[user]
name = John Doe
email = johndoe@mycompany.com
[core]
sshCommand = "ssh -i ~/.ssh/id_rsa_my_company"
# ~/Projects/Personal/.gitconfig
[user]
name = John Doe
email = johndoe@myblog.com
[core]
sshCommand = "ssh -i ~/.ssh/id_rsa_personal"
Now if you go into respective folders and run git config user.email, you must see
the relevant email.