How to programmatically determine the current checked out Git branch

Question

In a Unix or GNU scripting environment (e.g. a Linux distro, Cygwin, OSX), what is the best way to determine which Git branch is currently checked out in a working directory?

One use of this technique would be automatically labeling a release (like svnversion would do with Subversion).

Please also see my related question: How to programmatically determine whether a Git checkout is a tag, and if so what is the tag name?

Answer 1

Here is what I do:

git branch | sed --quiet 's/* \(.*\)/\1/p'

The output would look like this:

$ git branch | sed --quiet 's/* \(.*\)/\1/p'
master
$

Answer 2

That's one solution. If you add it to your .bashrc, it'll display the current branch in the console.

# git branch
parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/(\1) /'
}
$PS1="\$(parse_git_branch)$PS1"

However it's pretty limited. But there is a great project called git sh, which is doing exactly that (and much more).

Answer 3

A robust way to do this is to use git name-rev:

$ git name-rev --name-only HEAD
master

This is generally considered more reliable because it is a "plumbing" command and is designed to be parsed by a program (in fact, the only output is exactly what you want). The output of git branch is more variable and could change in the future.

A good way to describe a release is to use the git describe command. This refers the current commit to the nearest tag, providing a stable indicator of which branch was built. If you label your build as coming from the "integ_2" branch, you still won't know what was actually included in the build.

Answer 4

This one works for me. The --no-color part is, or can be, important if you want a plain string back.

git branch --no-color | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/'

Answer 5

The correct solution is to take a peek at contrib/completions/git-completion.bash does that for bash prompt in __git_ps1. Removing all extras like selecting how to describe detached HEAD situation, i.e. when we are on unnamed branch, it is:

branch_name="$(git symbolic-ref HEAD 2>/dev/null)" ||
branch_name="(unnamed branch)"     # detached HEAD

branch_name=${branch_name##refs/heads/}

git symbolic-ref is used to extract fully qualified branch name from symbolic reference; we use it for HEAD, which is currently checked out branch.

Alternate solution could be:

branch_name=$(git symbolic-ref -q HEAD)
branch_name=${branch_name##refs/heads/}
branch_name=${branch_name:-HEAD}

where in last line we deal with the detached HEAD situation, using simply "HEAD" to denote such situation.