prompt_yes_or_no.function.bash

prompt_yes_or_no.function.bash

# Prompt for Yy/Nn, if not the expected answer ask again
# Parameter: A string of prompt; Default answer(Y/N)
# return 0 for yes and 1 for no
prompt_yes_or_no(){
	if [ ${#} -ne 2 ]; then
		printf --\
			'Fatal: %s: Function paramater quantity mismatch!  Please report bug\n'\
			"${FUNCNAME[0]}"\
			1>&2
		exit 1
	fi

	local -r prompt="${1}"; shift
	local -r default_answer="${1}"

	local -i default_answer_exit_status

	# Validate input
	case "${default_answer}" in
		Y|y)
			default_answer_exit_status=0
		;;
		N|n)
			default_answer_exit_status=1
		;;
		*)
			printf --\
				'Fatal: %s: Wrong default_answer parameter format\n'\
				"${FUNCNAME[0]}"\
				1>&2
			exit 1
		;;
	esac

	# Do the job here
	printf --\
		"%s"\
		"${prompt}"
	while read -r answer; do
		case ${#answer} in
			0) # default
				return ${default_answer_exit_status}
			;;
			1)
				case "${answer}" in
					n|N)
						return 1
					;;
					y|Y)
						return 0
					;;
					*)
						printf --\
							"%s"\
							"${prompt}"
					;;
				esac
			;;
			*)
				printf --\
					'Error: %s: Unexpected case occurred, please report bug.\n'\
					"${FUNCNAME[0]}"\
					1>&2
				exit 1
			;;
		esac
	done
}; declare -rf prompt_yes_or_no