Checks if current git branch needs to pull, push, if it has diverged, or if it is up to date with the remote branch.

check-git-branch-status.sh

#!/bin/sh
# This script checks if the current branch needs to pull, push, if it has 
# diverged, or if it is up-to-date with the remote branch.

# Credits to: http://stackoverflow.com/questions/3258243/check-if-pull-needed-in-git

# Check if git is installed.
hash git 2>/dev/null || { echo >&2 "This script requires git to be installed."; exit 1; }

# Update remote branch to fetch latest remote commit SHA.
git remote update

# Grab all sha's.
local_commit=$(git rev-parse @)
remote_commit=$(git rev-parse @{u})
base_commit=$(git merge-base @ @{u})

# Check branch status
if [ $local_commit = $remote_commit ]; then
  echo "Branch is up-to-date with origin."
elif [ $local_commit = $base_commit ]; then
  echo "Branch is behind origin."
elif [ $remote_commit = $base_commit ]; then
  echo "Branch is ahead of origin."
else
  echo "Branch has diverged."
fi