#!/bin/sh
# bzme re-compress gzip, zip, ... files into bzip2
#==============================================================================
# Copyright (C) 1999-2002 MandrakeSoft (tvignaud@mandrakesoft.com)
# By Thierry Vignaud <tvignaud@mandrakesoft.com>
#
# 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, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#
# The GNU General Public License can be read at
# http://www.fsf.org/copyleft/gpl.html
#==============================================================================
#
#  Know bugs:
#  ----------
#  - bash getopt isn't gnu style aware, ie cmd opt1 file1 file2 opt2
#    will result in ignoring opt2 option
#
#==============================================================================
#
#  Changelog:
#  ----------
#  v1.0: original release
#  v1.1: fix space usage (use pipe rather than temp file)
#  v1.2: keep source file, not bz2 one if eof while decompressing
#  v1.3: reduce used cpu time (decompressing only one time;
#        source crc error 're detected through PIPESTATUS)
#  v1.4: add zip support on popular^h^h^h^h^hGwenole request
#  v1.5:
#        - make zip method acting as z one (remove original file,
#          keeping only smallest file, displaying size gain, ...)
#          thus giving occasion to factorize some common code
#        - check that the source file does exists
#        - handle corrupted zip source file
#        - comment the script and verbos-ize() some old changes
#        - use cheaper shell tests
#        - add GPL reference
#        - update online help to reflect optional options and newer
#          supported formats
#        - remove dependency on sed by using ${1%old}new_extension
#  v1.6: 
#        - print error message on stderr rather than on stdin
#        - factorize/simplify zip method (fix erase temp files on bzip2ing
#          error)
#        - typo fixes
#        - simplify for_each(file) loop
#        - add "Know bugs" and TODO sections
#        - add -h and -k options
#        - if -k (keep) option is used, keep all files
#  v1.7: - handle file names with spaces
#  v1.8:
#        - able to recompress rar files too
#        - adapt for Fedora/RHEL
#==============================================================================
#
#
# TODO:
#      - retrieve my patch for solaris file utils
#      - add trap for zip method (is it really useful?)
#      - add a man page
#      - move bzme in its own package that requires tar too


# Defaults
force=
keep=

# Corrupted source error message
src_err_msg ()
{	if [ "$2" != 0 ]; then
		echo "Corrupted source file ($1) !" 1>&2
		rm -f "$TARGET"
		STATUS=1
	fi
}

gz_compr ()
{	zcat "$1" | bzip2 -9 > "$TARGET"
	# Keep PIPESTATUS
	MY_STATUS=( ${PIPESTATUS[*]} ) 
	src_err_msg "$1" ${MY_STATUS[0]}
	if [[ "${MY_STATUS[1]}" != "0" ]]; then
		echo "error while bziping !" 1>&2
		STATUS=1
	fi
}

create_temp_dir ()
{
	[[ -z "$TMPDIR" ]] && TMPDIR=$TMP
	[[ -z "$TMPDIR" ]] && TMPDIR=~/tmp
	MY_TMP=$(mktemp -d $TMPDIR/gzme.XXXXXX)
}

rar_compr ()
{
	create_temp_dir
	(cd $MY_TMP; unrar x "$OLDPWD/$1") > /dev/null
	src_err_msg "$1" $?
	tar cfj  "$TARGET" -C $MY_TMP .
	if [[ $? != 0 ]]; then
		echo "error while taring !" 1>&2
		STATUS=1
	fi
	# Removing temporary files
	rm -fr $MY_TMP
}

zip_compr ()
{
	create_temp_dir
	unzip -qd $MY_TMP "$1"
	src_err_msg "$1" $?
	tar cfj  "$TARGET" -C $MY_TMP .
	if [[ $? != 0 ]]; then
		echo "error while taring !" 1>&2
		STATUS=1
	fi
	# Removing temporary files
	rm -fr $MY_TMP
}

compress ()
{	echo -n "Compressing $1 ... "
	if [[ ! -f "$1" ]]; then
		echo "Source file doesn't exist" 1>&2
		return
	fi
	STATUS=0
	SIZE=$(du "$1"|cut -f 1 -d "	")
	SIZE_o=$(du -b "$1"|cut -f 1 -d "	")
	if [[ -f "$TARGET" ]];	then
		if [[ -n $force ]];then
			rm -f "$TARGET"
		else
			echo "$TARGET already exists !!" 1>&2
			echo "Use -f to force it"
			return
		fi
	fi
	# Do the real compression job
	$METHOD "$1"
	# if there was an error
	if [[ $STATUS = 1 ]]; then
		[[ -z $keep ]] && rm -f "$TARGET"
		return
	fi
	# Compare size in order to only keep the smallest file
	SIZE2=$(du "$TARGET"|cut -f 1 -d "	")
	SIZE2_o=$(du -b "$TARGET"|cut -f 1 -d "	")
	if [[ $SIZE_o -lt $SIZE2_o && -z $force_compress ]]
	then
		echo "=> $TARGET is bigger than $1 ($SIZE"kb" => $SIZE2"kb") !!!"
		echo "Use -F to force the recompression"
		[[ -z $keep ]] && rm -f "$TARGET"
	else
		echo "=> $TARGET ($SIZE"kb" => $SIZE2"kb")"

		[[ -z $keep ]] && rm -f "$1"
	fi
}

while getopts Ffhk opt;  do
  case "$opt" in
      F) force_compress="yes";;
      f) force="yes";;
      k) keep="yes";;
      h)
	  echo "Usage: bzme [-Ffhk] file.*.({,t}gz|Z|zip)"
	  exit 1;;
      *)
	  echo "See bzme -h for usage"
	  exit 1;;
  esac
done
shift $((OPTIND - 1))

echo keeping: $keep

while [[ "$1" != "" ]]
do
	#default method is gz,.Z,.z,..
	METHOD=gz_compr
	case "$1" in
		*.bz2)	echo "$1: already compressed!"; shift;continue;;
		*.tgz)	TARGET=${1%.tgz}.tar.bz2;;
		*.Z)	TARGET=${1%.Z}.bz2;;
		*.gz)	TARGET=${1%.gz}.bz2;;
		*.rar)	
			METHOD=rar_compr
			TARGET=${1%.rar}.bz2
			;;
		*.zip)
			METHOD=zip_compr
			TARGET=${1%.zip}.tar.bz2
			;;
		*)	echo "$1: unknown file extension => ignored"; shift; continue;;
	esac
	compress "$1"
	shift
done