#!/bin/bash

if [ "$1" = "rm" ]; then
    branches_file=${2:-"orphaned-branches.txt"}
    echo "Removing branches specified in $branches_file"
    while read branch; do
        git branch -D $branch
    done < $branches_file
    exit 0
fi

tmpdir=`mktemp -d`
git ls-remote --refs --heads | awk '{print $2}' | sed 's/refs\/heads\///' | while read branch; do
    mkdir -p "${tmpdir}/${branch}"
done

rm -f orphaned-branches.txt
git branch | sed 's/\* //' | while read branch; do
    [ ! -d "${tmpdir}/${branch}" ] && echo $branch >> orphaned-branches.txt
done

rm -rf $tmpdir

cat orphaned-branches.txt
echo "---------------------------------------------------------------"
echo "Orphaned branches written to orphaned-branches.txt"
echo "Edit this file to contain only branches you want to remove,"
echo "then rerun $0 with the 'rm' argument to delete them"