Shell script to synchronise git fork to an upstream repository and prune/delete local branches which are merged

clean_merged_branches.sh

#!/bin/sh
#
# This script helps to automatically synchronise a GitHub fork to the upstream repository
#
# It will perform the following functions:
# - Fetch from upstream
# - Prune branches (disconnect from remote)
# - Swap to the master branch
# - Merge upstream/master into origin/master
# - Remove local branches which have been pruned
#
# NOTE: The upstream repository should be added with:
# $ git remote add upstream <url/ssh>
#
# NOTE: Changes should be pushed to the origin repository after
#
# Mike Goodfellow 2015
# https://mikegoodfellow.co.uk
#

# Fetch upstream changes
git fetch upstream

# Prune deleted branches
git fetch -p

# Swap to master branch
git checkout master

# Merge in the changes from upstream/master
git merge upstream/master

# Check if any branches need pruning
git branch --merged master | grep -v 'master$'

if [ $? -eq 1 ]; then
    echo "No local branches need deleting"
else
    echo "Local branches need deleting"
git branch --merged master | grep -v 'master$' | xargs git branch -d
fi

# Update our fork master with any changes
git push

echo "Finished!"