In a git hook is the current working directory guaranteed to be within the git repository?

Question

Experimentally it seems that git hooks get run with the current directory set to be the root of the repository. However, I can't see any guarantee about that in the git documentation. Should I rely on the current working directory to locate the git repository, or is there a better way to work out the git repository associated with the hook?

Solution 1

It is based on the value set for environment variable GIT_DIR. It is set to the root of the repository when the hook starts running. Many hooks, especially those doing a pull from another repo, unset ( and reset) this environment variable as needed.

Solution 2

The current answers appear to be outdated. As of 2.9.0, the docs state the following:

Before Git invokes a hook, it changes its working directory to either the root of the working tree in a non-bare repository, or to the $GIT_DIR in a bare repository.

https://git-scm.com/docs/githooks/2.9.0

Solution 3

You can use the environment variable $GIT_DIR. $GIT_DIR points at the .git directory.

Comments

[PuercoPop]

Does $GIT_DIR has a trailing slash ?

[David Lord]

How likely is it that $GIT_DIR/.. will point to the repository root?

[holygeek]

It's not foolproof. Don't use $GIT_DIR/... That will break when the repo is a bare repo. A bare repo has no working directory hence no "repository root". Also it will break when .git is a link instead.

[David Lord]

Figured. Any way to get the repo root under normal usage? For a pre-commit hook which uses the repo as configuration files for a program, for instance?

[Ghopper21]

This is NOT a correct answer. GIT_DIR is NOT always set to the root of the repo. See this blog.

[Ghopper21]

This is NOT correct in all cases. See this blog.

[Vince]

@Ghopper21 That article isn't entirely correct either. It says that for the post-commit hook, the current directory is the top level of the working tree. However, my very simple post-commit script didn't find other scripts at the top level of the working tree. e.g.: .git/hooks/post-commit: 1: .git/hooks/post-commit: post-commit_push_gitweb.sh: not found

[Novice C]

Great answer. A clarification was made in later revisions (2.13.0). "An exception are hooks triggered during a push (pre-receive, update, post-receive, post-update, push-to-checkout) which are always executed in $GIT_DIR."

[jmcker]

Source/context for the above quote: git-scm.com/docs/githooks#_description

[Ben Mares]

In plain language: it's the top-level directory of your repository. ("Bare" essentially refers to a repository consisting of only the .git directory, and with no files checked out.)