#!/bin/bash
#
# upd-updates
#
# Copyright (C) 2007  Red Hat, Inc.  All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

usage() {
	if [ $1 -ne 0 ]; then
		>&2
	fi
	echo "upd-updates <updates.img> <file0> [<file1> [...]]"
	exit $1
}

[ -z "$1" -o -z "$2" ] && usage 1
[ "$1" == "--help" ] && usage 0

TARGET="$1" ; shift

OK=no
if [ -e "$TARGET" -a -w "$TARGET" -o -w $(dirname "$TARGET") ] ; then
	OK=yes
fi

if [ "$OK" == "no" ]; then
	echo "upd-updates: cannot write to $TARGET" 1>&2
	exit 2
fi

n=1
while [ -n "$(eval echo '${'$n'}')" ]; do
	arg="$(eval echo '${'$n'}')"
	[ ${arg} == "--help" -o ${arg} == "-h" ] && usage 0

	if [ ! -r ${arg} ]; then
		echo "upd-updates: cannot read ${arg}" 1>&2
		exit 3
	fi
	n=$(($n + 1))
done

TMPDIR=$(mktemp -d)
if [ ! -d ${TMPDIR} ]; then
	echo "upd-updates: cannot make tmpdir ${TMPDIR}" 1>&2
	exit 4
fi

if [ -e "$TARGET" ]; then
	zcat "$TARGET" | ( cd $TMPDIR ; cpio -di --quiet -dm --unconditional )
	[ $? -eq 0 ] || exit 5
fi

echo ${@} | tr ' ' '\0' | tr -d '\n' | cpio --null -H newc --quiet -o | \
	( cd $TMPDIR ; cpio -di --quiet -dm --unconditional )

[ $? -eq 0 ] || exit 6

(cd $TMPDIR ; find . -depth -print0 | cpio -H newc --quiet --null -o ) | \
	gzip -9 > "$TARGET"

[ $? -eq 0 ] || exit 7

rm -rf "$TMPDIR"

[ $? -eq 0 ] || exit 8

exit 0