git-prune-merged

#!/bin/bash
usage(){
	sed 's/^..//' <<USAGE
		usage: git prune-merged <remote> [--mainline=<revision>] [--prefix=<prefix>]

		Removes (from the specified remote) branches whose tips are reachable from the mainline.

		<remote> is optional if there is exactly one remote configured for the current repository.

		Options:

			-n, --simulate

			Do not actually delete anything, just list what would be deleted

			--remote

			Delete from the server instead of locally
			If both --remote and --local are specified, branches are deleted from both

			--local

			Delete locally instead of from the server (default).
			If both --remote and --local are specified, branches are deleted from both

			--mainline=<revision>

			Specifies the revision to use as the mainline.
			Defaults to refs/remotes/<remote>/master
			If pruneRemote.mainline is configured, that will be used.

			--prefix=<prefix>

			Only consider remote branches beginning with the prefix <prefix>.
			If pruneRemote.prefix is configured, that will be used.

			--ignore=<ref> [<ref>...]

			Never consider the ref <ref>. Use this to ensure that certain refs
			never get deleted. Specify the complete ref, eg:
			  refs/remotes/foo/bar

			Multiple refs may be listed, seperated by spaces.
			If pruneRemote.ignore is configured, that will be added to the list.
USAGE
}

pretend(){
	printf '+ ' >&2
	printf '%q ' "$@" >&2
	printf '\n' >&2
}

current="$(git symbolic-ref HEAD)"
[ -n "$current" ] || { printf 'Refusing to prune-merged with a detached HEAD\n' >&2; exit 1; }

remote=
mainline="$(git config pruneRemote.mainline)"
prefix="$(git config pruneRemote.prefix)"
ignore="$current $(git config pruneRemote.ignore)"
do_simulate=0
do_local=
do_remote=

while [ $# -gt 0 ]; do
	arg="$1"; shift

	case "$arg" in
		-n|--simulate)
			do_simulate=1
			;;
		--mainline=*)
			mainline="${arg#*=}"
			;;
		--prefix=*)
			prefix="${arg#*=}"
			;;
		--ignore=*)
			[ -n "$ignore" ] && ignore="$ignore "
			ignore="$ignore${arg#*=}"
			;;
		--local)
			do_local=1
			;;
		--remote)
			do_remote=1
			;;
		--help)
			usage
			exit
			;;
		*)
			if [ -z "$remote" ]; then
				remote="$arg"
			else
				printf "Unknown argument '%s'\n" "$arg" >&2
				usage >&2
				exit 1
			fi
			;;
	esac
done

if [ -z "$do_local" ] && [ "$do_remote" = "1" ]; then
	do_local=0
fi

if [ -z "$do_remote" ] && [ "$do_local" = "1" ]; then
	do_remote=0
fi

if [ -z "$do_local" ] && [ -z "$do_remote" ]; then
	do_local=1
	do_remote=0
fi

if [ -z "$remote" ]; then
	remote="$(git remote)"
	if [ "$remote" != "$(head -n 1 <<<"$remote")" ]; then
		printf 'You must specify a remote\n' >&2
		exit 1
	fi
fi

[ -z "$mainline" ] && mainline="${mainline:-refs/remotes/$remote/master}"

ignored=()
while read ref; do
	[ -n "$(sed 's/\s\s*//g' <<<"$ref")" ] || continue
	ignored=( "${ignored[@]}" "$ref" )
done < <( sed 's/\s\s*/\n/g' <<<"$ignore" )

if [ $do_local -eq 1 ]; then
	merged=()
	while read hash type ref; do
		[ "$ref" != "$mainline" ] || continue

		do_ignore=0
		for ignored_ref in "${ignored[@]}"; do
			if [ "$ref" = "$ignored_ref" ]; then
				do_ignore=1
				break
			fi
		done
		[ $do_ignore -eq 0 ] || continue

		if [ -z "$(git rev-list -n 1 "$ref" "^$mainline")" ]; then
			merged=( "${merged[@]}" "$ref" )
		fi
	done < <( git for-each-ref "refs/heads/$prefix" )

	if [ ${#merged[@]} -gt 0 ]; then
		if [ $do_simulate -eq 1 ]; then
			for ref in "${merged[@]}"; do
				pretend git update-ref -d "$ref"
			done
		else
			for ref in "${merged[@]}"; do
				git update-ref -d "$ref"
			done
		fi
	fi
fi

if [ $do_remote -eq 1 ]; then
	remote_merged=()
	while read hash type ref; do
		[ "$ref" != "refs/remotes/$remote/HEAD" ] || continue
		[ "$ref" != "$mainline" ] || continue

		do_ignore=0
		for ignored_ref in "${ignored[@]}"; do
			if [ "$ref" = "$ignored_ref" ]; then
				do_ignore=1
				break
			fi
		done
		[ $do_ignore -eq 0 ] || continue

		branch="${ref#refs/remotes/$remote/}"
		if [ -z "$(git rev-list -n 1 "$ref" "^$mainline")" ]; then
			remote_merged=( "${remote_merged[@]}" ":refs/heads/$branch" )
		fi
	done < <( git for-each-ref "refs/remotes/$remote/$prefix" )

	if [ ${#remote_merged[@]} -gt 0 ]; then
		if [ $do_simulate -eq 1 ]; then
			pretend git push "$remote" "${remote_merged[@]}" >&2
		else
			git push "$remote" "${remote_merged[@]}"
		fi
	fi
fi