#!/bin/sh -
#
# $NetBSD: zdiff,v 1.5 2010/04/14 20:30:28 joerg Exp $
#
# $OpenBSD: zdiff,v 1.2 2003/07/29 07:42:44 otto Exp $
#
# Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
# Copyright (c) 2010 Joerg Sonnenberger <joerg@NetBSD.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# Sponsored in part by the Defense Advanced Research Projects
# Agency (DARPA) and Air Force Research Laboratory, Air Force
# Materiel Command, USAF, under agreement number F39502-99-1-0512.
#

# Set $prog based on $0
case $0 in
	*cmp)	prog=cmp
		;;
	*)	prog=diff
		;;
esac
USAGE="usage: $0 [options] file1 [file2]"

check_suffix() {
	case "$1" in
	*[._-][Zz])
		setvar $2 "${1%??}"
		setvar $3 "gzip -cdqf"
		;;
	*[._-]bz)
		setvar $2 "${1%???}"
		setvar $3 "bzip2 -cdqf"
		;;
	*[._-]gz)
		setvar $2 "${1%???}"
		setvar $3 "gzip -cdqf"
		;;
	*[._-]xz)
		setvar $2 "${1%???}"
		setvar $3 "xz -cdqf"
		;;
	*[._-]bz2)
		setvar $2 "${1%????}"
		setvar $3 "bzip2 -cdqf"
		;;
	*[._-]lzma)
		setvar $2 "${1%?????}"
		setvar $3 "xz -cdqf"
		;;
	*.t[ag]z)
		setvar $2 "${1%??}"ar
		setvar $3 "gzip -cdqf"
		;;
	*.tbz)
		setvar $2 "${1%??}"ar
		setvar $3 "bzip2 -cdqf"
		;;
	*.tbz2)
		setvar $2 "${1%???}"ar
		setvar $3 "bzip2 -cdqf"
		;;
	*.t[lx]z)
		setvar $2 "${1%??}"ar
		setvar $3 "xz -cdqf"
		;;
	*)
		setvar $2 "$1"
		setvar $3 ""
		;;
	esac
}


# Pull out any command line flags so we can pass them to diff/cmp
# XXX - assumes there is no optarg
flags=
while test $# -ne 0; do
	case "$1" in
		--)
			shift
			break
			;;
		-)
			break
			;;
		-*)
			flags="$flags $1"
			shift
			;;
		*)
			break
			;;
	esac
done

if [ $# -eq 1 ]; then
	# One file given, compare compressed to uncompressed
	files="$1"
	check_suffix "$1" files filt
	if [ -z "$filt" ]; then
		echo "z$prog: unknown suffix" 1>&2
		exit 1
	fi
	$filt -- "$1" | $prog $flags -- - "$files"
	status=$?
elif [ $# -eq 2 ]; then
	# Two files given, compare the two uncompressing as needed
	check_suffix "$1" files filt
	check_suffix "$2" files2 filt2
	if [ -z "$filt" -a -z "$filt2" ]; then
		$prog $flags -- "$1" "$2"
	elif [ -z "$filt" -a -n "$filt2" -a "$1" != "-" ]; then
		$filt2 -- "$2" | $prog $flags -- "$1" -
	elif [ -n "$filt" -a -z "$filt2" -a "$2" != "-" ]; then
		$filt -- "$1" | $prog $flags -- - "$2"
	else
		tmp=`mktemp -t z$prog.XXXXXXXXXX` || exit 1
		trap "rm -f $tmp" 0 1 2 3 13 15
		${filt2:-cat} -- "$2" > $tmp || exit $?
		${filt:-cat} -- "$1" | $prog $flags -- - "$tmp"
	fi
	status=$?
else
	echo "$USAGE" 1>&2
	exit 1
fi

exit $status