#!/bin/sh
#-
# Copyright (c) 2014 Dag-Erling Smørgrav
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD: stable/11/usr.sbin/vigr/vigr.sh 275768 2014-12-14 16:40:46Z des $
#

proc error {
	echo @Argv > !2
	exit 1
}

proc usage {
	error "usage: vigr [-d dir]"
}

# Check arguments
while getopts d: opt {
	match $opt {
	with d
		setglobal etcdir = $(OPTARG)
		
	with *
		usage
		
	}
}

# Look for the current group file
setglobal grpfile = ""$(etcdir:-/etc)/group""
if test ! -f $(grpfile)  {
	error "Missing group file"
}

# Create a secure temporary working directory
setglobal tmpdir = $[mktemp -d -t vigr]
if test -z $(tmpdir) -o ! -d $(tmpdir)  {
	error "Unable to create the temporary directory"
}
setglobal tmpfile = ""$(tmpdir)/group""

# Clean up on exit
trap "exit 1" INT
trap "rm -rf '$(tmpdir)'" EXIT
set -e

# Make a copy of the group file for the user to edit
cp $(grpfile) $(tmpfile)

while : {
	# Let the user edit the file
	$(EDITOR:-/usr/bin/vi) $(tmpfile)

	# If the result is valid, install it and exit
	if chkgrp -q $(tmpfile)  {
		install -b -m 0644 -C -S $(tmpfile) $(grpfile)
		exit 0
	}

	# If it is not, offer to re-edit
	while : {
		echo -n "Re-edit the group file? "
		read ans
		match $ans {
		with [Yy]|[Yy][Ee][Ss]
			break
			
		with [Nn]|[Nn][Oo]
			exit 1
			
		}
	}
}