Asynchronous Module Sample Code

//m.js
var fs = require('fs');

module.exports = function(filename, callback) {
	fs.readFile(filename, 'utf8', function(err, data){
	  if (err) throw err;
	  callback(data);
  });
}

//u.js
var getContent = require('./m');

getContent('h.txt', function(data) {
  console.log(data);
});

//h.txt
Hello Nodejs.