git-grounded: A small script to cleanup a local git repository after feature development

git-grounded

#! /bin/bash

set -e

remote=${1:-origin}

# Determine local HEAD
head=$(git symbolic-ref HEAD)

# Determine main branch of remote repo
remote_head=$(git ls-remote --symref ${remote} HEAD | awk '$1=="ref:" && $3=="HEAD" {print $2}')

# Bail if local HEAD doesn't match the name of main branch on remote
if [[ $head != $remote_head ]]
then
	printf "Error: HEAD of remote %s is %s which is different than local HEAD, %s. Please update local HEAD to match and try again.\n" $remote $remote_head $head
	exit 1
fi

# Pull changes from remotes
git pull --ff-only
# Prune any remote branches that no longer exist in upstream remotes
git remote prune $(git remote)
# Prune any local branches that have already been merged into the main branch
git for-each-ref --merged $head | awk -v head=$head '/refs\/heads\// && match($3, head)==0 {printf("delete %s %s\n", $3, $1)}' | git update-ref --stdin