Super simple socket listener in Node

node-socket-listener.js

var net = require('net');

function log(msg) {
	process.stdout.write(msg.trim() + "\n", 'utf8');
}

var port = Number(process.argv[2]);
if ( !port || isNaN(port) ) {
	return log('Need valid PORT number as argument.');
}

net.createServer(function(socket) {

	log('New connection!');

	socket.setEncoding('utf8');
	socket.on('data', function(data) {
		data = data.trim();
		log('Incoming: ' + data.length + ' bytes');
		log('"' + data + '"');

		this.write('abc');
	});

	socket.on('end', function() {
		log('Connection closed');
	});

}).listen(port, function() {
	log('Starting server...');
});