Bash Script Template (ref: https://betterdev.blog/minimal-safe-bash-script-template/)

bash-script-template.sh

#!/usr/bin/env bash

set -Eeuo pipefail
trap cleanup SIGINT SIGTERM ERR EXIT

script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd -P)

usage() {
	cat <<EOF # remove the space between << and EOF, this is due to web plugin issue
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
}

cleanup() {
	trap - SIGINT SIGTERM ERR EXIT
	# script cleanup here
}

setup_colors() {
	if [[ -t 2 ]] && [[ -z "${NO_COLOR-}" ]] && [[ "${TERM-}" != "dumb" ]]; then
		NOFORMAT='\033[0m' RED='\033[0;31m' GREEN='\033[0;32m' ORANGE='\033[0;33m' BLUE='\033[0;34m' PURPLE='\033[0;35m' CYAN='\033[0;36m' YELLOW='\033[1;33m'
	else
		NOFORMAT='' RED='' GREEN='' ORANGE='' BLUE='' PURPLE='' CYAN='' YELLOW=''
	fi
}

log() {
	if [ "${#}" -eq 1 ]; then
		local lvl="INFO"
		local msg="${1}"
	else
		local lvl="${1}"
		local msg="${2}"
	fi
	echo "$(date +'%H:%M:%S') [${lvl}] - ${msg}"
}

die() {
	if [ "${#}" -eq 1 ]; then
		local lvl="ERROR"
		local msg="${1}"
		local code=1
	else
		local lvl="${1}"
		local msg="${2}"
		local code="${3}"
	fi
	log "${lvl}" "${msg}"
	exit "${code}"
}

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

	while :; do
		case "${1-}" in
		-h | --help) usage ;;
		-v | --verbose) set -x ;;
		--no-color) NO_COLOR=1 ;;
		-f | --flag) flag=1 ;; # example flag
		-p | --param)          # example named parameter
			param="${2-}"
			shift
			;;
		-?*) die "Unknown option: $1" ;;
		*) 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 "$@"
setup_colors

# script logic here

msg "${RED}Read parameters:${NOFORMAT}"
msg "- flag: ${flag}"
msg "- param: ${param}"
msg "- arguments: ${args[*]-}"