#!/bin/sh
# sh is buggy on RS/6000 AIX 3.2. Replace above line with #!/bin/ksh

# Zcmp and zdiff are used to invoke the cmp or the  diff  pro-
# gram  on compressed files.  All options specified are passed
# directly to cmp or diff.  If only 1 file is specified,  then
# the  files  compared  are file1 and an uncompressed file1.gz.
# If two files are specified, then they are  uncompressed  (if
# necessary) and fed to cmp or diff.  The exit status from cmp
# or diff is preserved.

PATH="/bin:$PATH"; export PATH
prog="${0##*/}"
case "$prog" in
  *cmp) comp=${CMP-cmp}   ;;
  *)    comp=${DIFF-diff} ;;
esac

OPTIONS=
FILES=
for ARG
do
    case "$ARG" in
    -*)	OPTIONS="$OPTIONS $ARG";;
     *)	if test -f "$ARG"; then
            FILES="$FILES $ARG"
        else
            echo "${prog}: $ARG not found or not a regular file" >&2
	    exit 2
        fi ;;
    esac
done
if test -z "$FILES"; then
	echo "Usage: $prog [${comp}_options] file [file]" >&2
	exit 2
fi
set $FILES
if test $# -eq 1; then
	case "$1" in
		*[-.]gz* | *[-.][zZ] | *.t[ga]z)
			compressor=gzip
			FILE=`printf %s "$1" | sed 's/[-.][zZtga]*$//'`
			;;
		*.bz2)
			compressor=bzip2
			FILE="${1%.bz2}"
			;;
		*.lzma)
			compressor=lzma
			FILE="${1%.lzma}"
			;;
		*.xz)
			compressor=xz
			FILE="${1%.xz}"
			;;
		*)
			FILE="$1"
			;;
	esac
	if test "$1" = "$FILE"; then
		echo "${prog}: file \`$1' has unrecognized suffix" >&2
		exit 2
	fi
	$compressor -cd "$1" | $comp $OPTIONS - "$FILE"

elif test $# -eq 2; then
	case "$1" in
		*[-.]gz* | *[-.][zZ] | *.t[ga]z)
			compressor1=gzip ;;
		*.bz2)
			compressor1=bzip2 ;;
		*.lzma)
			compressor1=lzma ;;
		*.xz)
			compressor1=xz ;;
		*)
			compressor1=cat ;;
	esac
	case "$2" in
		*[-.]gz* | *[-.][zZ] | *.t[ga]z)
			compressor2=gzip ;;
		*.bz2)
			compressor2=bzip2 ;;
		*.lzma)
			compressor2=lzma ;;
		*.xz)
			compressor2=xz ;;
		*)
			compressor2=cat ;;
	esac
	case "$compressor1$compressor2" in
		catcat)
			$comp $OPTIONS "$1" "$2" ;;
		*cat)
			$compressor1 -cdfq "$1" | $comp $OPTIONS - "$2" ;;
		cat*)
			$compressor2 -cdfq "$2" | $comp $OPTIONS "$1" - ;;
		*)
			TF=`mktemp -t zdiff.XXXXXXXXXX` || exit 1
			trap 'trap - EXIT; rm -f "$TF"; exit 2' EXIT HUP INT PIPE TERM
			$compressor2 -cdfq "$2" > "$TF" || exit
			$compressor1 -cdfq "$1" | $comp $OPTIONS - "$TF"
                        STAT="$?"
			rm -f "$TF" || STAT=2
			trap - EXIT HUP INT PIPE TERM
			exit $STAT ;;
	esac
else
	echo "Usage: $prog [${comp}_options] file [file]" >&2
	exit 2
fi
