Can gitconfig options be set conditionally?

Question

Via Github I use the same set of "dot files" on several different computers and servers. On the Macs and Linux boxes under my direct control I have Sublime Text 2 installed and set up as my git merge and commit editor of choice. However, on remote (i.e., not under my direct control) servers I would select to use vim.

I would rather not create and maintain a second .gitconfig for those remote servers. Is there a way to do something like this:

[core]
    if [[ $IS_REMOTE -eq 1 ]]; then
        editor = "vim"
    else
        editor = "subl -n -w"
    fi

where I've somehow set $IS_REMOTE based on the hostname?

Answer 1

No, Git config does not support checks or conditional statements. But your underlying shell probably does, so you can use something like:

[core]
    editor = "if [[ $IS_REMOTE -eq 1 ]]; then ED='vim'; else ED='subl -n -w'; fi; $ED"

If you need to do something more complicated than that, you could just throw the shell code into a script, of course, like

[core]
    editor = "my_edi_script.sh"

with my_edit_script.sh containing something like:

#!/bin/bash
if [[ $IS_REMOTE -eq 1 ]]; then
    ED="vim"
else
    ED="subl -n -w"
fi

$ED some argument or other

Edit: The my_edit_script.sh would have to be in the $PATH, of course :)

Answer 2

You can conditionally include another Git config file based on your Git directory or branch in Git 2.13 and later.

Put your default configuration in file ~/.gitconfig as usual. At the end, conditionally include another configuration file:

[user]
    email = [email protected]
    name = John McGehee

# All work Git repositories are in a subdirectory of ~/work.
# All other Git repositories are outside ~/work.
[includeIf "gitdir:~/work/"]
    path = .gitconfig.work

Then, in ~/.gitconfig.work add or override configuration values you want when using a repository located in ~/work or any subdirectory thereof:

[user]
    email = [email protected]

You can observe the difference by changing to a Git directory under ~/work, and running:

git config user.email

Try the same command in a Git directory that is not under ~/work.

Answer 3

The [include] section learned by git-config in v1.7.9 gets you most of the way there.

While it doesn't let you write runtime conditionals, it does give you a framework for refactoring your ~/.gitconfig into several parts: the shared section, and the env-specific sections. After that, you can symlink something like ~/.gitconfig.local to the relevant env-specific config file, and include ~/.gitconfig.local from ~/.gitconfig.

The symlinking part can be scripted and done automatically as part of your dotfiles' init script.

From the command line, that include path can be added via:

git config --global include.path '~/.gitconfig.local'

I use the quotes above specifically to prevent the shell from expanding ~ to an absolute path.

That adds the following section to your ~/.gitconfig:

[include]
    path = ~/.gitconfig.local

Here's a snippet from the git-scm book showing the general format:

[include]
    path = /path/to/foo.inc ; include by absolute path
    path = foo ; expand "foo" relative to the current file
    path = ~/foo ; expand "foo" in your $HOME directory