How to find the current git branch in detached HEAD state

Question

I can find the current git branch name by doing either of these:

git branch | awk '/^\*/ { print $2 }'
git describe --contains --all HEAD

But when in a detached HEAD state, such as in the post build phase in a Jenkins maven build (or in a Travis git fetch), these commands doesn't work.

My current working solution is this:

git show-ref | grep $(git log --pretty=%h -1) | sed 's|.*/\(.*\)|\1|' | sort -u | grep -v HEAD

It displays any branch name that has the last commit on its HEAD tip. This works fine, but I feel that someone with stronger git-fu might have a prettier solution?

Answer 1

A more porcelain way:

git log -n 1 --pretty=%d HEAD

# or equivalently:
git show -s --pretty=%d HEAD

The refs will be listed in the format (HEAD, master) - you'll have to parse it a little bit if you intend to use this in scripts rather than for human consumption.

You could also implement it yourself a little more cleanly:

git for-each-ref --format='%(objectname) %(refname:short)' refs/heads | awk "/^$(git rev-parse HEAD)/ {print \$2}"

with the benefit of getting the candidate refs on separate lines, with no extra characters.