shell-base/script

#!/bin/sh

set -eu

usage() {
	printf "Usage: %s [-h]\n" "$0"
}

help() {
    cat << EOH
 SYNOPSIS
    $0 [-h]

 DESCRIPTION

    $0 does things!

 OPTIONS

    -h    Show this help
EOH
}

on_interrupt() {
	print "Process aborted!\n"

	exit 130
}

main() {
	while getopts "hf:" option; do
		case "${option}" in
			h) help; exit 0;;
			f) FOO="$OPTARG";;
			?) log -l error "$(usage)"; exit 1;;
		esac
	done

	FOO="${FOO:-defaultValue}"

	# log [-t] [-l debug|error] message

	exit 0
}

log() {
	LEVEL=info
	TIME=

	while getopts "tl:" option; do
		case "${option}" in
			l) LEVEL="$OPTARG"; shift $((OPTIND-1));;
			t) TIME="$(printf "[%s] " "$(date +'%Y-%m-%dT%H:%m:%S.%s')")"; shift $((OPTIND-1));;
			*) exit 1;;
		esac
	done

	if [ -t 2 ] && [ -z "${NO_COLOR-}" ]; then
		case "${LEVEL}" in
			debug) COLOR="$(tput setaf 3)";;
			error) COLOR="$(tput setaf 1)";;
			*) COLOR="$(tput sgr0)"
		esac
	fi

	printf "%s%s%s\n" "${COLOR:-}" "${TIME:-}" "$*" >&2
}

trap on_interrupt INT

main "$@"