#!/bin/sh

​

# Copyright (C) 2015 Hans-Peter Jansen

# Copyright (C) 1998, 2002, 2004 Free Software Foundation

# Copyright (C) 1993 Jean-loup Gailly

​

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

​

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

​

# You should have received a copy of the GNU General Public License along

# with this program; if not, write to the Free Software Foundation, Inc.,

# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

​

​

PATH="/usr/bin:$PATH"; export PATH

check=0

pipe=0

opt=

files=

keep=0

res=0

old=0

new=0

block=1024

# block is the disk block size (best guess, need not be exact)

​

warn="(does not preserve modes and timestamp)"

tmp=`mktemp -d ${TMPDIR-/tmp}/zfoo.XXXXXX` || {

       echo 'cannot create temporary directory' >&2

       exit 1

}

trap "rm -rf $tmp/" 0 1 2 3 6 13 15

set -C

echo hi > $tmp/1

echo hi > $tmp/2

if test -z "`(${CPMOD-cpmod} $tmp/1 $tmp/2) 2>&1`"; then

  cpmod=${CPMOD-cpmod}

  warn=""

fi

​

if test -z "$cpmod" && ${TOUCH-touch} -r $tmp/1 $tmp/2 2>/dev/null; then

  cpmod="${TOUCH-touch}"

  cpmodarg="-r"

  warn="(does not preserve file modes)"

fi

​

# check about xz extension

xz $tmp/1 &> /dev/null

ext=`echo $tmp/1* | sed "s|$tmp/1||"`

rm -rf $tmp/

trap - 0 1 2 3 6 13 15

if test -z "$ext"; then

  echo xznew: error determining xz extension

  exit 1

fi

if test "$ext" = ".gz"; then

  echo xznew: cannot use .gz as xz extension.

  exit 1

fi

​

for arg

do

  case "$arg" in

  -*)     opt="$opt $arg"; shift;;

   *)     break;;

  esac

done

​

if test $# -eq 0; then

  echo "recompress .gz or .tgz files into $ext (xz) files"

  echo usage: `echo $0 | sed 's,^.*/,,'` "[-tv9KP]" file.gz...

  echo "  -t tests the new files before deleting originals"

  echo "  -v be verbose"

  echo "  -9 use the slowest compression method (optimal compression)"

  echo "  -K keep a .gz file when it is smaller than the $ext file"

  echo "  -P use pipes for the conversion $warn"

  exit 1

fi

​

opt=`echo "$opt" | sed -e 's/ //g' -e 's/-//g'`

case "$opt" in

  *t*) check=1; opt=`echo "$opt" | sed 's/t//g'`

esac

case "$opt" in

  *K*) keep=1; opt=`echo "$opt" | sed 's/K//g'`

esac

case "$opt" in

  *P*) pipe=1; opt=`echo "$opt" | sed 's/P//g'`

esac

if test -n "$opt"; then

  opt="-$opt"

fi

​

for i do

  m=`echo $i | sed 's/\.tgz$//'`

  if test -f "$m.tgz" ; then

   echo "Renaming file *.tgz to *.tar.gz"

   mv "$i" "$m.tar.gz"

   n=`echo $i | sed 's/\.tgz$/\.tar/'`

  else 

   n=`echo $i | sed 's/\.gz$//'`

  fi

  if test ! -f "$n.gz" ; then

    echo $n.gz not found

    res=1; continue

  fi

  test $keep -eq 1 && old=`wc -c < "$n.gz"`

  if test $pipe -eq 1; then

    if gzip -d < "$n.gz" | xz $opt > "$n$ext"; then

      # Copy file attributes from old file to new one, if possible.

      test -n "$cpmod" && $cpmod $cpmodarg "$n.gz" "$n$ext" 2> /dev/null

    else

      echo error while recompressing $n.gz

      res=1; continue

    fi

  else

    if test $check -eq 1; then

      if cp -p "$n.gz" "$n.$$" 2> /dev/null || cp "$n.gz" "$n.$$"; then

    :

      else

    echo cannot backup "$n.gz"

        res=1; continue

      fi

    fi

    if gzip -d "$n.gz"; then

      :

    else

      test $check -eq 1 && mv "$n.$$" "$n.gz"

      echo error while uncompressing $n.gz

      res=1; continue

    fi

    if xz $opt "$n"; then

      :

    else

      if test $check -eq 1; then

    mv "$n.$$" "$n.gz" && rm -f "$n"

        echo error while recompressing $n

      else

    # gzip $n  (might be dangerous if disk full)

        echo error while recompressing $n, left uncompressed

      fi

      res=1; continue

    fi

  fi

  test $keep -eq 1 && new=`wc -c < "$n$ext"`

  if test $keep -eq 1 && test `expr \( $old + $block - 1 \) / $block` -lt \

                  `expr \( $new + $block - 1 \) / $block`; then

    if test $pipe -eq 1; then

      rm -f "$n$ext"

    elif test $check -eq 1; then

      mv "$n.$$" "$n.gz" && rm -f "$n$ext"

    else

      xz -d "$n$ext" && gzip "$n" && rm -f "$n$ext"

    fi

    echo "$n.gz smaller than $n$ext -- unchanged"

​

  elif test $check -eq 1; then

    if xz -t "$n$ext" ; then

      rm -f "$n.$$" "$n.gz"

    else

      test $pipe -eq 0 && mv "$n.$$" "$n.gz"

      rm -f "$n$ext"

      echo error while testing $n$ext, $n.gz unchanged

      res=1; continue

    fi

  elif test $pipe -eq 1; then

    rm -f "$n.gz"

  fi

done

exit $res

​