Git: How to check if the local and remote branches point to the same commit (i.e. in sync)?

Question

How could I check if feature_branch and origin/feature_branch point to the same commit?

Answer 1

You can compare the output of git-rev-parse, such as in this bit of shell script:

export BRANCH_A=feature_branch
export BRANCH_B=origin/feature_branch

if [ x"$(git rev-parse $BRANCH_A)" = x"$(git rev-parse $BRANCH_B)" ]
then
    echo $BRANCH_A and $BRANCH_B are the same
fi

If you're not interested in using this in a script, but just want some indication of where feature_branch and origin/feature_branch are relative to each other, then the top of the output of git status will tell you their relative positions if they are not the same, e.g.:

$ git status
# On branch foo
# Your branch is behind 'origin/foo' by 187 commits, and can be fast-forwarded.

However, note that this only works if your git config indicates that origin/feature_branch is "upstream" for feature_branch. If you've created the local branch from a pre-existing remote-tracking branch, this will typically be the case. If, instead, feature_branch was a new branch you created locally, you can set up that association in your config by pushing the branch with -u, e.g. git push -u origin feature_branch.)

Answer 2

git rev-parse origin/foo_branch will not get you the latest commit hash on the remote branch. It will give you the latest commit hash that your local git repository knows about on the remote branch.

If you want to compare whether your local foo_branch is up to date with the current remote, you likely want:

# remote commit hash.
# will do a network request to get latest.
git ls-remote --head --exit-code origin foo_branch | cut -f 1

# local commit hash.
git rev-parse foo_branch

Alternatively, if you want to use git rev-parse, you should fetch the latest changes first before running rev-parse:

git fetch origin foo_branch
git rev-parse origin/foo_branch

I like the git ls-remote approach because it leaves your local repository untouched.