Can “git pull --all” update all my local branches?

Question

I often have at least 3 remote branches: master, staging and production. I have 3 local branches that track those remote branches.

Updating all my local branches is

Answer 1

If refs/heads/master can be fast-forwarded to refs/remotes/foo/master, the output of

git merge-base refs/heads/master refs/remotes/foo/master

should return the SHA1 id that refs/heads/master points to. With this, you can put together a script that automatically updates all local branches that have had no diverting commits applied to them.

This little shell script (I called it git-can-ff) illustrates how it can be done.

#!/bin/sh

set -x

usage() {
    echo "usage: $(basename $0)  " >&2
    exit 2
}

[ $# -ne 2 ] && usage

FROM_REF=$1
TO_REF=$2

FROM_HASH=$(git show-ref --hash $FROM_REF)
TO_HASH=$(git show-ref --hash $TO_REF)
BASE_HASH=$(git merge-base $FROM_REF $TO_REF)

if [ "$BASE_HASH" = "$FROM_HASH" -o \
     "$BASE_HASH" = "$FROM_REF" ]; then
    exit 0
else
    exit 1
fi