#! /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
invocation_name=$0
args=
default_prog=lzip

# Loop over args until pattern 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"
		echo "transparent concatenation of any combination of compressed and"
		echo "non-compressed files. If any given file is compressed, its uncompressed"
		echo "content is used. If a given file does not exist, zcat tries the"
		echo "compressed file name corresponding to the default compressor selected."
		echo "The supported compressors are gzip, bzip2, lzip and xz."
		echo
		echo "Usage: ${invocation_name} [OPTIONS] [CAT_OPTIONS] [FILES]"
		echo
		echo "CAT_OPTIONS are passed directly to cat."
		echo "The exit status from cat is preserved."
		echo
		echo "Options:"
		echo "  -h, --help          display this help and exit"
		echo "  -V, --version       output version information and exit"
		echo "      --gzip          use gzip as default decompressor"
		echo "      --bzip2         use bzip2 as default decompressor"
		echo "      --lzip          use lzip as default decompressor (default)"
		echo "      --xz            use xz as default decompressor"
		echo
		echo "Report bugs to lzip-bug@nongnu.org"
		echo "Lzip home page: http://www.nongnu.org/lzip/lzip.html"
		exit 0 ;;
	--version | --ve* | -V)
		echo "Zcat VERSION"
		echo "Copyright (C) 2009 Antonio Diaz Diaz."
		echo "This script is free software: you have unlimited permission"
		echo "to copy, distribute and modify it."
		exit 0 ;;
	--gz*)
		default_prog=gzip ;;
	--bz*)
		default_prog=bzip2 ;;
	--lz*)
		default_prog=lzip ;;
	--xz*)
		default_prog=xz ;;
	-)
		;;
	--)
		shift; break ;;
	-?*)
		args="${args} $1" ;;
	 *)
		break ;;
	esac
	shift
done

if test $# -eq 0; then
	${default_prog} -cd | cat ${args}
	exit $?
fi

retval=0
for i in "$@" ; do
	prog="${default_prog} -cdfq"
	case "$i" in
	*.gz | *.tgz)
		prog="gzip -cdfq" ;;
	*.bz2 | *.tbz | *.tbz2)
		prog="bzip2 -cdfq" ;;
	*.lz | *.tlz)
		prog="lzip -cdfq" ;;
	*.xz | *.txz)
		prog="xz -cdfq" ;;
	*)
		if test -f "$i"; then prog=cat
		else
			case ${default_prog} in
			gzip)
				if test -f "$i.gz"; then i="$i.gz"; fi ;;
			bzip2)
				if test -f "$i.bz2"; then i="$i.bz2"; fi ;;
			lzip)
				if test -f "$i.lz"; then i="$i.lz"; fi ;;
			xz)
				if test -f "$i.xz"; then i="$i.xz"; fi ;;
			esac
		fi ;;
	esac
	${prog} -- "$i" | cat ${args}
	r=$?
	test "$r" -ne 0 && retval="$r"
done

exit ${retval}