#!/bin/sh
#
# Utility to examine how much space a package will require
# Sums column 3 of tar output and displays archivename and sum 
#

callname=`basename $0 `

function usage () {
	echo " "
	echo "$callname: displays expected usage of an archive (packed with tar and gzip)"
	echo "  Usage: $callname archivename"
	echo "  Example: $callname bin.tgz "
	echo " "
}

if [ "$1" = "" -o "$1" = '-h' -o "$1" = '-?' ]; then
	usage
	exit 1
fi

echo -n "archive $1 "
cat $1 | gunzip | tar tvf - | awk -v column="3" \
	'BEGIN { printf  "would take "}
	{ total += $column }
	END { print total, "bytes extracted"}'
