#!/bin/sh

# debsummer - Create md5sums file for given package(s)
#
# Copyright (C) 2002  Patrick L. Bernier <pat@TZoNE.ORG>
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 2, as
#    published by the Free Software Foundation.
#
#    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, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# v1.0 (2002/10/12) -- Initial attempt
# v1.1 (2002/12/14) -- Quoted some filenames
# v1.2 (2008/10/06) -- True Bourne shell syntax; allow empty md5sums
#
# Source: http://www.TZoNE.ORG/~pat/sw/debsummer/

PATH=/usr/bin:/bin

usage() {
	cat >&2 <<EOT
Usage: debsummer [-cfov] [ -i dpkginfodir ] [ -m md5sumsdir ] packagename ...

-c	Do not include config files
-f	Force overwrite of existing md5sums
-i dir	Specify alternate dpkg info dir
-m dir	Specify alternate dir for .md5sums files
	(e.g. for non-root use)
-o	Do not include world-unreadable files
-v	Increase verbosity level
EOT
}

process() {
	pkgname="$1"
	listfile="$dpkginfo/$pkgname.list"
	md5file="$md5dir/$pkgname.md5sums"
	conffile="$dpkginfo/$pkgname.conffiles"

	if [ -f "$md5file" ]; then
		if [ "$force" -eq 1 ]; then
			rm -f -- "$md5file"
			touch -- "$md5file"
			chmod 644 -- "$md5file"
		else
			echo "Skipping package '$pkgname': md5sums file exists (use -f to force)" >&2
			return 1
		fi
	fi

	if [ ! -f "$listfile" ]; then
		echo "Package '$pkgname' not found." >&2
		return 1
	fi

	if [ ! -r "$listfile" ]; then
		echo "Can't read $listfile" >&2
		return 1
	fi

	[ $verbose -gt 0 ] && echo "$pkgname"

	: > "$md5file"
	cat $listfile | while read f
	do
		if [ -f "$f" ]; then
			[ "$skipconf" -eq 1 -a -f "$conffile" ] && if grep -- "$f" "$conffile" >/dev/null 2>&1; then
				[ $verbose -gt 0 ] && echo "skipping conffile $f"
				continue
			fi
			if [ "$nobody" -eq 1 ]; then
				if su nobody -c "test -r \"$f\""; then
					:
				else
					[ $verbose -gt 0 ] && echo "skipping world-unreadable $f"
					continue
				fi
			fi
			if [ $verbose -gt 1 ]; then
				md5sum -- "$f" | sed -e 's#/##' | tee -a -- "$md5file"
			else
				md5sum -- "$f" | sed -e 's#/##' >> "$md5file"
			fi
		fi
	done

}

if [ ! -r /etc/debian_version ]; then
	echo "I think you're not running Debian... debsummer can't help you."
fi

dpkginfo=/var/lib/dpkg/info
md5dir=$dpkginfo
force=0
verbose=0
nobody=0
skipconf=0
while getopts cfi:m:ov opt
do
	case $opt in
	c)	skipconf=1 ;;
	f)	force=1 ;;
	i)	dpkginfo=$OPTARG ;;
	m)	md5dir=$OPTARG ;;
	o)	nobody=1 ;;
	v)	verbose=$(($verbose+1)) ;;
	\?)	usage; exit 1 ;;
	esac
done
shift `expr $OPTIND - 1`

if [ "$#" -lt 1 ]; then
	usage
	exit 1
fi

if [ ! -d "$dpkginfo" -o ! -r "$dpkginfo" ]; then
	echo "Cannot read $dpkginfo" >&2
	exit 1
fi

if [ ! -d "$md5dir" -o ! -w "$md5dir" -o ! -r "$md5dir" ]; then
	echo "Cannot read/write $md5dir" >&2
	exit 1
fi

error=0
while [ "$1" != "" ]; do
	process "$1"
	[ $? -ne 0 ] && error=1
	shift
done

exit $error

### debsummer ###