zutils/zcat.in

#! /bin/sh
# Zcat - Cat wrapper for compressed files.
# Copyright (C) 2009 Antonio Diaz Diaz.
#
# This script is free software: you have unlimited permission
# to copy, distribute and modify it.

LC_ALL=C
export LC_ALL
args=
default_prog=gzip
two_hyphens=0

# Loop over args until a filename is found
while [ x"$1" != x ] ; do

	case "$1" in
	--help | --he* | -h)
		echo "Zcat - Cat wrapper for compressed files."
		echo
		echo "Zcat is a wrapper script around the cat command that allows transparent"
		echo "concatenation of any combination of compressed and non-compressed files."
		echo "If any given file is compressed, its uncompressed content is used. If a"
		echo "given file does not exist, zcat tries the compressed file names"
		echo "corresponding to the supported compressors. If no files are specified,"
		echo "the standard input is decompressed using the selected compressor and"
		echo "sent to stdout."
		echo "The supported compressors are gzip, bzip2, lzip and xz."
		echo
		echo "Usage: $0 [OPTIONS] [CAT_OPTIONS] [FILES]"
		echo
		echo "CAT_OPTIONS are passed directly to cat."
		echo "The exit status from cat is preserved."
		echo
		echo "Options:"
		echo "  -h, --help          display this help and exit"
		echo "  -V, --version       output version information and exit"
		echo "      --gzip          use gzip as decompressor for stdin (default)"
		echo "      --bzip2         use bzip2 as decompressor for stdin"
		echo "      --lzip          use lzip as decompressor for stdin"
		echo "      --xz            use xz as decompressor for stdin"
		echo
		echo "Report bugs to zutils-bug@nongnu.org"
		echo "Zutils home page: http://www.nongnu.org/zutils/zutils.html"
		exit 0 ;;
	--version | --ve* | -V)
		echo "Zcat VERSION"
		echo "Copyright (C) 2009 Antonio Diaz Diaz."
		echo "This script is free software: you have unlimited permission"
		echo "to copy, distribute and modify it."
		exit 0 ;;
	--gz*)
		default_prog=gzip ;;
	--bz*)
		default_prog=bzip2 ;;
	--lz*)
		default_prog=lzip ;;
	--xz*)
		default_prog=xz ;;
	- | -f)
		;;
	--)
		shift ; two_hyphens=1 ; break ;;
	-?*)
		args="${args} $1" ;;
	 *)
		break ;;
	esac
	shift
done

if [ $# = 0 ]; then
	${default_prog} -cdfq | cat ${args}
	exit $?
fi

retval=0
for i in "$@" ; do
	if [ "$i" = "--" ] && [ ${two_hyphens} = 0 ] ; then two_hyphens=1
	else
		if [ ! -f "$i" ]; then
			if [ -f "$i.gz" ];    then i="$i.gz"
			elif [ -f "$i.bz2" ]; then i="$i.bz2"
			elif [ -f "$i.lz" ];  then i="$i.lz"
			elif [ -f "$i.xz" ];  then i="$i.xz"
			else
				echo "$0: File \"$i\" not found or not a regular file" 1>&2
				if [ ${retval} = 0 ]; then retval=1 ; fi
				continue
			fi
		fi
		bindir=`echo "$0" | sed -e 's,[^/]*$,,'`
		prog_name=`"${bindir}"zutils -t -- "$i"`
		case "${prog_name}" in
		gzip)	prog="gzip -cdfq" ;;
		bzip2)	prog="bzip2 -cdfq" ;;
		lzip)	prog="lzip -cdfq" ;;
		xz)	prog="xz -cdfq" ;;
		*)	prog=cat ;;
		esac
		${prog} -- "$i" | cat ${args}
		r=$?
		if [ $r != 0 ]; then retval=$r ; fi
	fi
done

exit ${retval}