There are a couple ways of doing this. If you are on Git 2.22+, then the
git-branch
porcelain command now supports a flag for this.
$ git branch --show-current
main
If you are on an older version of Git or looking for a plumbing command that is
more appropriate for scripting, then git-rev-parse
is what you're looking
for.
$ git rev-parse --abbrev-ref HEAD
main