go fmt precommit hook

	#!/bin/sh
     2	# Copyright 2012 The Go Authors. All rights reserved.
     3	# Use of this source code is governed by a BSD-style
     4	# license that can be found in the LICENSE file.
     5	
     6	# git gofmt pre-commit hook
     7	#
     8	# To use, store as .git/hooks/pre-commit inside your repository and make sure
     9	# it has execute permissions.
    10	#
    11	# This script does not handle file names that contain spaces.
    12	
    13	gofiles=$(git diff --cached --name-only --diff-filter=ACM | grep '\.go$')
    14	[ -z "$gofiles" ] && exit 0
    15	
    16	unformatted=$(gofmt -l $gofiles)
    17	[ -z "$unformatted" ] && exit 0
    18	
    19	# Some files are not gofmt'd. Print message and fail.
    20	
    21	echo >&2 "Go files must be formatted with gofmt. Please run:"
    22	for fn in $unformatted; do
    23		echo >&2 "  gofmt -w $PWD/$fn"
    24	done
    25	
    26	exit 1