sample bash script. (Minimal safe Bash script template)

sample-bash-script.sh

#!/usr/bin/env bash
set -Eeuo pipefail

function usage() {
	cat <<-EOF
		Usage: $(basename "${BASH_SOURCE[0]}") [-h] [-v] [-f] -p param_value arg1 [arg2...]

		Script description here.

		Available options:
		-h, --help      Print this help and exit
		-v, --verbose   Print script debug info
		-f, --flag      Some flag description
		-p, --param     Some param description
	EOF
	exit
}

function msg() {
	echo >&2 -e "${1:-}"
}

function die() {
	local msg=$1
	local code=${2:-1} # default exit status 1
	msg "$msg"
	exit "$code"
}

function parse_params() {
	# default values of variables set from params
	flag=0
	param=''

	while :; do
		case "${1:-}" in
		-h | --help) usage ;;
		-v | --verbose) set -x ;;
		-f | --flag) flag=1 ;; # example flag
		-p | --param)          # example named parameter
			param="${2:-}"
			shift
			;;
		-?*) die "Unknown option: $1" ;; # die is the original function
		*) break ;;
		esac
		shift
	done

	args=("$@")

	# check required params and arguments
	[[ -z "${param:-}" ]] && die "Missing required parameter: param"
	[[ ${#args[@]} -eq 0 ]] && die "Missing script arguments"

	return 0
}

parse_params "$@"

# script logic here

echo "- flag: ${flag}"
echo "- param: ${param}"
echo "- arguments: ${args[*]:-}"