make-delete-ancient-branches.sh

#!/bin/bash

#
# generates a script that will delete merged branches
# that were last updated prior to 2016-10-01
#

function list_ancient_branches() {
	git branch -r --merged | \
		grep -v HEAD | \
		xargs -n1 -I {} git show -s --format="%cI %h {}" {} | \
		egrep -v '^(2017|2016-1)'
}

list_ancient_branches | while read date sha branch; do
	echo "# $date $branch $sha"
	echo git push origin --delete ${branch/origin\/}
	echo
done