git-behind

#!/usr/bin/env sh

usage() {
  echo -n "${scriptName} [OPTION]... [FILE]...

Returns true if local working copy is behind the git remote.
"
}

BRANCH_OR_TAG=`git-ref-type`
if  [ "$BRANCH_OR_TAG" != "branch" ]; then
  echo "Not on a branch."
  exit 1
fi

git fetch
BEHIND=$(git rev-list HEAD..FETCH_HEAD --count)

if  [ "$BEHIND" -gt "0" ]; then
  exit 0
else
  exit 1
fi