Pretty $PATH printer!

liste.bash

#!/usr/bin/env bash
#
# Created by Uğur "vigo" Özyılmazel on 2017-04-26.
# Copyright (c) 2017 VB YAZILIM. All rights reserved.

set -e
set -o pipefail

usage() {
cat <<EOF

usage: liste [-d <delimeter> | -h] INPUT

    -d <delimeter>          : Set custom delimeter. Accepts 1 single char.
                              default is :
try:
    
    liste "\$PATH" | sort
    liste "foo:bar:baz"

EOF
}

pretty_print(){
    tr "${DEFAULT_DELIMETER}" "\n" <<< "${1}"
}

DEFAULT_DELIMETER=":"
SORT_OUTPUT="NO"
CMD_OPTIONS=":hd:"
while getopts $CMD_OPTIONS opt; do
    case $opt in
        h)
            usage >&2
            exit 0
            ;;
        d)
            if [[ ${#OPTARG} -gt 1 ]]; then
                echo "Invalid delimeter char: Must be a single character" >&2
                exit 1
            fi
            DEFAULT_DELIMETER="${OPTARG}"
            shift $((OPTIND-1))
            ;;
        \?)
            echo "Invalid option: -$OPTARG" >&2
            exit 1
            ;;
        :)
            echo "Option -$OPTARG requires an argument." >&2
            usage >&2
            exit 0
            ;;
    esac
done

if [[ ${#} -eq 1 ]]; then
    pretty_print "${1}"
    exit 0
fi

echo "Invalid usage..." >&2
usage >&2
exit 1