#!/bin/sh
# Copyright 1997, 1998 Patrick Volkerding, Moorhead, MN USA
# Copyright 2002 Slackware Linux, Inc., Concord, CA USA
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  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.
#

# debug switch to allow to bypass use of rpm2cpio provided by the rpm package
USERPM2CPIO=true
[ "$TMPDIR" == "" ] && TMPDIR=/tmp
if [ ! -d "$TMPDIR" ]; then
	echo "TMPDIR=$TMPDIR is not a dir" > /dev/stderr
	exit 1
fi
WORKDIR=`mktemp -d $TMPDIR/$$XXXXXX`
if [ $? != 0 ]; then
	echo "Failed to make tmp workdir for file i/o conversion" > /dev/stderr
	exit 1
fi

if [ "$1" = "" ]; then
  echo "$0:  Converts RPM format to standard GNU tar + GNU zip format."
  if [ -e /etc/slackware-version ]; then
    echo "            (view converted packages with \"less\", install and remove"
    echo "            with \"installpkg\", \"removepkg\", \"pkgtool\", or manually"
    echo "            with \"tar\")"
  fi
  echo
  echo "Usage:      $0 <file.rpm>"
  if [ "`basename $0`" = "rpm2tgz" ]; then
    echo "            (Outputs \"file.tgz\")"
  else
    echo "            (Outputs \"file.tar.gz\")"
  fi
  exit 1;
fi
for i in $* ; do
  if [ ! "$1" = "$*" ]; then
    echo "Processing file: $i"
  fi
  rm -rf ${WORKDIR}/* || exit 1 ; # clear the way, just in case of mischief

  # Determine if this is a source or binary RPM.
  # If we have getrpmtype, use that.  Otherwise, try "file".
  if type -p getrpmtype 1> /dev/null 2> /dev/null; then
    if getrpmtype -n $i | grep source 1> /dev/null 2> /dev/null ; then
      isSource=1
    else
      isSource=0
    fi
  else # use file.  This works fine on Slackware, and is the default.
    if file $i | grep RPM | grep " src " 1> /dev/null 2> /dev/null ; then
      isSource=1
    else
      isSource=0
    fi
  fi

  ofn=${WORKDIR}/`basename $i .rpm`.cpio
  if $USERPM2CPIO && which rpm2cpio 1> /dev/null 2> /dev/null ; then
    rpm2cpio $i > $ofn 2> /dev/null
    if [ ! $? = 0 ]; then
      echo "... rpm2cpio failed.  (maybe $i is not an RPM?)"
      ( rm -rf "${WORKDIR}/*" )
      continue
    fi
  else # less reliable than rpm2cpio...
    # get offset of start of payload
    PAYLOADOFFSET=`rpmoffset < $i` 
    #identify compression
    PAYLOADHEAD=`dd ibs=${PAYLOADOFFSET} skip=1 if=$i 2> /dev/null | dd bs=10 count=1 2> /dev/null`
    if echo ${PAYLOADHEAD} | grep -e $'^\037\213' > /dev/null ; then 
   	echo "found gzip magic bytes"
	decomp="gzip"
    elif echo ${PAYLOADHEAD} | grep -e "^BZh" > /dev/null ; then
        echo "found bzip magic bytes"
	decomp="bzip2"
    else
        echo  " $i - no magic compression identifier found - skipping file"
        ( rm -rf "${WORKDIR}/*" )
        continue
    fi
    echo -n "  trying to decompress with ${decomp}..."
    dd ibs=`rpmoffset < $i` skip=1 if=$i 2> /dev/null | ${decomp} -dc > $ofn 2> /dev/null 
    if [ $? = 0 ]; then
      echo "  OK"
    else
      echo "  FAILED"
      echo  " $i  failed to decompress - skipping file"
      ( rm -rf "${WORKDIR}/*" )
      continue
    fi
  fi
  DEST=${WORKDIR}
  #if [ "$isSource" = "1" ]; then
  #   DEST=$DEST/$(basename $(basename $i .rpm) .src)
  #fi
  mkdir -p $DEST
  ( cd $DEST
    cpio --extract --preserve-modification-time --make-directories < $ofn 1> /dev/null 2> /dev/null
    rm -f $ofn
    find . -type d -perm 700 -exec chmod 755 {} \; )
  ( cd ${WORKDIR} ; tar cf - . ) > `basename $i .rpm`.tar
  gzip -9 `basename $i .rpm`.tar
  if [ "`basename $0`" = "rpm2tgz" ]; then
    mv `basename $i .rpm`.tar.gz `basename $i .rpm`.tgz
  fi
  ( rm -rf "${WORKDIR}/*" )
  echo
done
rm -rf ${WORKDIR}