#!/bin/bash

[ -t 0 ] && [ "$1" == "" ] &&
        echo "Concatenate files (gziped files decompressed) and print on the standard output." >&2 &&
        echo "Syntax: catz [<files>]" >&2 &&
        echo >&2 &&
        exit 1

[ ! -t 0 ] && cat - # output STDIN

while [ 1 ]; do
        [ "$1" == "" ] && exit
        [ "$1" == "-" ] && shift && continue
        if [[ "$1" =~ gz$ ]]; then
                zcat "$1"
        else
                cat "$1"
        fi
        shift
done