#!/bin/sh
# rpm2cpio - Shell-script version off "rpm2cpio"
# License: Believed tp be GNU LGPL, version 2.1 (Feb 1999)
# Revision: 120328

# This script is  descended from a file  that was  originally  part of
# RPM5 5.4.0.

pkg=$1
if [ "$pkg" = "" -o ! -e "$pkg" ]; then
    echo "no package supplied" 1>&2
   exit 1
fi

leadsize=96
o=`expr $leadsize + 8`
set `od -j $o -N 8 -t u1 $pkg`
il=`expr 256 \* \( 256 \* \( 256 \* $2 + $3 \) + $4 \) + $5`
dl=`expr 256 \* \( 256 \* \( 256 \* $6 + $7 \) + $8 \) + $9`
# echo "sig il: $il dl: $dl"

sigsize=`expr 8 + 16 \* $il + $dl`
o=`expr $o + $sigsize + \( 8 - \( $sigsize \% 8 \) \) \% 8 + 8`
set `od -j $o -N 8 -t u1 $pkg`
il=`expr 256 \* \( 256 \* \( 256 \* $2 + $3 \) + $4 \) + $5`
dl=`expr 256 \* \( 256 \* \( 256 \* $6 + $7 \) + $8 \) + $9`
# echo "hdr il: $il dl: $dl"

hdrsize=`expr 8 + 16 \* $il + $dl`
o=`expr $o + $hdrsize`
EXTRACTOR="dd if=$pkg ibs=$o skip=1"

COMPRESSION=`($EXTRACTOR |file -) 2>/dev/null`

if echo $COMPRESSION |grep -iq gzip; then
	DECOMPRESSOR=gunzip
elif echo $COMPRESSION |grep -iq bzip2; then
	DECOMPRESSOR=bunzip2
elif echo $COMPRESSION |grep -iq xz; then
	DECOMPRESSOR=unxz
elif echo $COMPRESSION |grep -iq cpio; then
	DECOMPRESSOR=cat
else
	DECOMPRESSOR=unxz
fi

$EXTRACTOR 2>/dev/null | $DECOMPRESSOR