#!/bin/sh
# Copyright 1997, 1998  Patrick Volkerding, Moorhead, MN USA
# Copyright 2002, 2004  Slackware Linux, Inc., Concord, CA USA
# Copyright 2006, 2009  Patrick Volkerding, Sebeka, MN 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.
#

CWD=$(pwd)

# Breaking the help out into it's own deal
usage() {
  echo "$0:  Converts RPM format to standard GNU tar + GNU zip format."
  echo "            (view converted packages with \"less\", install and remove"
  echo "            with \"installpkg\", \"removepkg\", \"pkgtool\", or manually"
  echo "            with \"tar\")"
  echo
  if [ "$(basename $0)" = "rpm2tgz" ]; then
    echo "Usage:      $0 [OPTION] <file.rpm>"
    echo "            (Outputs \"file.tgz\")"
    echo
    echo "  -s    extract the install scripts to /usr/doc/\$PRGNAM-\$VERSION/"
    echo "          for review."
    echo "  -S    extracts the install scripts to be executed on package installation"
    echo "          (only pre-install and post-install scripts used)"
    echo "          USE WITH CAUTION! "
    echo "  -n    name the output package using the rpm's metadata"
    echo "  -r    extract what the rpm's \"requires\" (dependencies)"
    echo "          as documention to /usr/doc/\$PRGNAM-\$VERSION/"
    echo "  -d    attempt a wellformed slack-desc from the rpm meta data"
    echo
  else
    echo "Usage:      $0 <file.rpm>"
    echo "            (Outputs \"file.tar.gz\")"
  fi
  exit 1;
}

# Create a new temporary directory with a secure filename:
make_temp_dir() {
  if [ -x "$(which mcookie)" ]; then
    tempd=/tmp/tmp.$(mcookie)
    mkdir -p -m 0755 $tempd
  elif [ -x "$(which openssl)" ]; then
    tempd=/tmp/tmp.$(dd if=/dev/urandom bs=1k count=1 2> /dev/null | openssl dgst -md5)
    mkdir -p -m 0755 $tempd
  elif [ -x "$(which md5)" ]; then
    tempd=/tmp/tmp.$(dd if=/dev/urandom bs=1k count=1 2> /dev/null | md5)
    mkdir -p -m 0755 $tempd
  elif [ -x "$(which mktemp)" ]; then
    tempd=$(mktemp -d)
    chmod 755 $tempd
  ## Uncomment for insecure use, but don't blame me:
  #else
  #  tempd=/tmp/tmp.$$
  #  mkdir -p -m 0755 $tempd
  fi
  if [ -d $tempd ]; then # success, return the name of the directory:
    echo $tempd
  else
    echo "ERROR:  Could not find mcookie, openssl, or md5."
    echo "        Exiting since a secure temporary directory could not be made."
    exit 1
  fi
}

# Get the meta data off of the rpm
get_meta_data() {
  RPM=$1
  PRGNAM=$(rpm -qp --qf %{NAME} $RPM )
  ARCH=$(rpm -qp --qf %{ARCH} $RPM )
  VERSION=$(rpm -qp --qf %{VERSION} $RPM )
  BUILD=$(rpm -qp --qf %{RELEASE} $RPM )
}

if [ "$1" = "" ]; then
  usage
fi

ARGS=$(getopt "hsSndr" $* )
set -- ${ARGS}
for i; do
  case "$1" in
    -s)
      DOC_SCRIPTS="true"
      shift
      ;;
    -S)
      INSTALL_SCRIPTS="true"
      shift
      ;;
    -r)
      DOC_REQUIRES="true"
      shift
      ;;
    -d)
      DESC="true"
      shift
      ;;
    -n)
      META_NAME="true"
      shift
      ;;
    --)
      shift
      break
      ;;
  esac
done


for i in $* ; do
  
  # Determine if this is a source or binary RPM.
  # If we have getrpmtype, use that.  Otherwise, try "file".
  if which 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 -w src 1> /dev/null 2> /dev/null ; then
      isSource=1
    else
      isSource=0
    fi
  fi

  # Create a temporary directory:
  TMPDIR=$(make_temp_dir)

  # Extract the RPM:
  ofn=$TMPDIR/$(basename $i .rpm).cpio
  if which rpm2cpio 1> /dev/null 2> /dev/null ; then
    rpm2cpio $i > $ofn 2> /dev/null
    if [ ! $? = 0 ]; then
      echo "ERROR:  rpm2cpio failed.  (maybe $i is not an RPM?)"
      rm -rf $TMPDIR
      continue
    fi
  else # less reliable than rpm2cpio...
    ( dd ibs=$(rpmoffset < $i) skip=1 if=$i 2> /dev/null | gzip -dc > $ofn 2>/dev/null ) || \
    ( dd ibs=$(rpmoffset < $i) skip=1 if=$i 2> /dev/null | bzip2 -dc > $ofn 2>/dev/null )
  fi
  DEST=$TMPDIR
  if [ "$isSource" = "1" ]; then
     DEST=$DEST/$(basename $(basename $i .rpm) .src)
  fi
  mkdir -p $DEST
  ( cd $DEST
    cpio -i -m -d < $ofn 1> /dev/null 2> /dev/null
    rm -f $ofn
    find . -type d -perm 700 -exec chmod 755 {} \;
  )

  # Save the scripts in the rpm as documentation
  if [ "$DOC_SCRIPTS" = "true" ]; then
    get_meta_data $i
    mkdir -p $TMPDIR/usr/doc/$PRGNAM-$VERSION/
    for state in PREIN POSTIN PREUN POSTUN ; do
      if [ "$(rpm -qp --qf %{$state} $i )" != '(none)' ] ; then
        rpm -qp --qf %{$state} $i > $TMPDIR/usr/doc/$PRGNAM-$VERSION/$state.script
      fi
    done
  fi

  # Save the scripts in the rpm to be installed
  if [ "$INSTALL_SCRIPTS" = "true" ]; then
    mkdir -p $TMPDIR/install
    echo '#!/bin/sh' > $TMPDIR/install/doinst.sh
    for state in PREIN POSTIN ; do
      if [ "$(rpm -qp --qf %{$state} $i )" != '(none)' ] ; then
        rpm -qp --qf %{$state} $i > $TMPDIR/install/doinst.sh
        echo "" >> $TMPDIR/install/doinst.sh
      fi
    done
  fi

  # Save the rpm's requires (dependencies) as documentation
  if [ "$DOC_REQUIRES" = "true" ]; then
    get_meta_data $i
    mkdir -p $TMPDIR/usr/doc/$PRGNAM-$VERSION/
    rpm -qp --qf %{REQUIRES} $i  > $TMPDIR/usr/doc/$PRGNAM-$VERSION/README-$PRGNAM-rpm-dependencies.txt
  fi

  # Save the rpm's summary and description as the slack-desc
  if [ "$DESC" = "true" ]; then
    mkdir -p $TMPDIR/install
    rpm -qp --qf %{SUMMARY} $i | sed -l 70 -r "s/^(.*)/$PRGNAM: $PRGNAM - \1\n/" > $TMPDIR/install/slack-desc
    rpm -qp --qf %{DESCRIPTION} $i | sed -l 70 -r "s/^/$PRGNAM: /" >> $TMPDIR/install/slack-desc
  fi

  # If this program was called as "rpm2targz", then repack as a plain
  # tar+gz archive.  If it was called as "rpm2tgz", use Slackware's
  # makepkg to produce the .tgz:
  if [ "$(basename $0)" = "rpm2tgz" ]; then
    ( 
      cd $TMPDIR
      if [ "$META_NAME" = "true" ]; then
        get_meta_data $CWD/$i
        makepkg -l y -c n $CWD/$PRGNAM-$VERSION-$ARCH-${BUILD}.tgz
      else
        makepkg -l y -c n $CWD/$(basename $i .rpm).tgz
      fi
    )
  else
    ( cd $TMPDIR ; tar cf - . ) > $(basename $i .rpm).tar
    gzip -9 $(basename $i .rpm).tar
  fi

  # Remove temporary directory:
  rm -rf $TMPDIR

done