#!/bin/bash
#
# The purpose of this software/script is to allow the user
# to view the contents of a Slackware package with out having
# to install, or untar (explode) the package. 
#
# This software is released and licensed under the GPL v2, for
# further documentation look at http://www.gnu.org/copyleft/gpl.html
# Some minor parts of this script were taken from the /sbin/installpkg
# on a Slackware 10.1 system. Those parts are protected by the copyright
# and disclaimer below.
#
# Copyright 1994, 1998, 2000  Patrick Volkerding, Concord, CA, USA
# Copyright 2001, 2003  Slackware Linux, Inc., Concord, CA, USA
# All rights reserved.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
#
# Author: James Caffrey <jamescaffrey@gmail.com>
# Version: 1.4.2
#
# Version of viewpkg
VER=1.4.2
CWD=`pwd`
PAGER=${PAGER:-/usr/bin/less}

usage() {
   #displays how to use viewpkg
   cat << EOF 
viewpkg $VER
A tool to view the contents of a Slackware package. Similar
to explodepkg but without writing the whole package to your
hard disk. Viewpkg is used for examining and debugging.

Options:
	-h|--help		Displays this help message
	-v|--version		Displays version information
Usage:
	`basename $0` [options] package_name
EOF
}

crunch() {
   # This function, and the implementation that
   # it serves was borrowed from /sbin/installpkg.
   # Thanks Pat. :)
   while read foo
   do
	echo $foo
   done
}

#if no args, bomb out
if [ $# = 0 ]; then
   usage
   exit 1
fi

# Parse the args
while [ "$1" ]
do
   case $1 in
	-h|--help)
	   usage
	   exit 1
	   ;;
	-v|--version)
	   echo "viewpkg $VER"
	   exit 1
	   ;;
	*)
	   #we use basename, so if user passes a 
	   #package name that is not in pwd
	   PKGDIR="`dirname $1`"
	   PKGNAME="`basename $1`"
	   if [ ! -e $1 ]; then
	     echo
	     echo "ERROR: package does not exist"
	     echo
	     exit 1
	   fi
	   shift
	   ;;
   esac
done

# Check to see if is a package, not
# just a tar gzip'd archive
cd $PKGDIR
if [ "`echo $PKGNAME | rev | cut -f 1 -d . | rev`" != "tgz" ]; then
   echo
   echo "ERROR: package name given, is not a package"
   echo "       it do not have a .tgz extension"
   echo
   exit 2
fi


# Some temp files
TMPPERM="/tmp/`basename $0`-$$-1"
TMPFILE="/tmp/`basename $0`-$$-2"

# Breakdown the package name
NAME=`basename $PKGNAME .tgz | rev | cut -f 4- -d - | rev`
#currently not using these, but maybe for future use
#VERSION=`basename $PKGNAME .tgz | rev | cut -f 3 -d - | rev`
#ARCH=`basename $PKGNAME .tgz | rev | cut -f 2 -d - | rev`
#BUILD=`basename $PKGNAME .tgz | rev | cut -f 1 -d - | rev`

(
# Give a nice header
echo "Package Name: `basename $PKGNAME .tgz`"
COMPRESSED=`gzip -l $PKGNAME | grep -v ratio | crunch | cut -f 1 -d ' '`
echo "Compressed Package Size: `expr $COMPRESSED / 1024` K"
UNCOMPRESSED=`gzip -l $PKGNAME | grep -v ratio | crunch | cut -f 2 -d ' '`
echo "Uncompressed Package Size: `expr $UNCOMPRESSED / 1024` K"
echo "Package Location: $PKGDIR/$PKGNAME"
echo "Package Description:"

# Find and print out slack-desc
cd $PKGDIR
tar -ztvf $PKGNAME | grep "slack-desc" > /dev/null
if [ $? = 0 ]; then 
   tar -zxOf $PKGNAME install/slack-desc | grep $NAME
else
   echo
   echo "No slack-desc file found in package. I guess"
   echo "that is problem one with this package. :)"
   echo 
fi

# Print out all files in archive
echo
echo "File List:"
#this gets permissions and ownerships
tar -ztvf $PKGNAME | cut -b 1-23 > $TMPPERM
#this gets directories and files
tar -ztvf $PKGNAME | cut -f 3 -d : | cut -c 4- > $TMPFILE
#lets put them together
paste $TMPPERM $TMPFILE

#this worked most of the time, execpt with
#files that were large you would see part
#of the file size listed
#tar -ztvf $PKGNAME | cut -b 1-24,52-

# Find and print out doinst.sh
echo
echo "Installation Script:"
tar -ztvf $PKGNAME | grep "doinst.sh" > /dev/null
if [ $? = 0 ]; then
   tar -zxOf $PKGNAME install/doinst.sh
fi
) | $PAGER

# Cleanup
rm -f $TMPPERM
rm -f $TMPFILE
cd $CWD

#########################ChangeLog###############################
#								#
#   20050508 1.4.2						#
#	*Simplified the implementation of breaking		#
#	 down the package name, no more loop			#
#								#
#   20050424 1.4.1						#
#	*Simplify the implementation of checking		#
#	 for if file is a Slackware package.			#
#	*Minor code clean up; elminated an if			#
#	 statement by using parameter expansion			#
#								#
#   20050405 1.4						#
#	*Added showing of compressed and			#
#	 uncompressed package size, mostly			#
#	 borrowed from /sbin/installpkg,			#
#	 thanks Pat. :)						#
#								#
#   20050326 1.3						#
#	*Added checking it see if file given			#
#	 is a Slackware package. Other wise			#
#	 any gzip'd tar file would work but			#
#	 but give errors					#
#								#
#   20050318 1.2						#
#	*Updated engine which displays				#
#	 file list						#
#								#
#   20050315 1.1						#
#	*Bug fixes, improper detection				#
#	 of slack-desc and doinst.sh files			#
#								#
#   20050310 1.0						#
#	*Initial release					#
#								#
#################################################################