How to write interactive CLI utility in node.js

Node.js is mainly a server development framework - accepting requests and responding to them over network. But sometimes need arises to write a CLI utility using node.js. The asynchronous nature of node.js can make it difficult to write a simple CLI utility that will ask series of questions and accept answers from the user. Recently I ran into such situation, here is how I wrote one. (Learnt about the ask function from this post)
gist

	var questions = [
	{ id:'fname', text:'First Name', answerType:'str' },
	{ id:'lname', text:'Last Name', answerType:'str' },
	{ id:'age', text:'Age', answerType:'int' },
	{ id:'weight', text:'Weight', answerType:'float' }
	]
	function ask(question, callback) {
	var stdin = process.stdin, stdout = process.stdout;
	stdin.resume();
	stdout.write(question + ": ");
	stdin.once('data', function(data) {
	data = data.toString().trim();
	callback(data);
	});
	}
	function process_answers(answers) {
	console.log(answers);
	}
	function main() {
	var i=0, l=questions.length, answers={};
	var process_val = function (val) {
	if(question.answerType == 'int') {
	answers[question.id] = parseInt(val, 10);
	} else if(question.answerType == 'float') {
	answers[question.id] = parseFloat(val);
	} else {
	answers[question.id] = val;
	}
	if(i<l-1) {
	question = questions[++i];
	ask(question.text, process_val);
	} else {
	process_answers(answers)
	}
	};
	var question = questions[i];
	ask(question.text, process_val);
	}
	main();

view raw node-cli.js hosted with ❤ by GitHub