Example tcp server write by NodeJS. Just telnet to port in config.

tcp_server.js

var net = require('net');

// Config
var config = {
	server: {
		port: 7890
	}
};


var clients = [];

// Add new method to net.Socket
net.Socket.prototype.log = function(msg)
{
	console.log(this.getName() + " -> Status: " + msg);
};
net.Socket.prototype.getName = function(msg)
{
	return this.remoteAddress + ":" + this.remotePort;
};
net.Socket.prototype.printLine = function(msg)
{
	this.write(String(msg) + "\n");
};
net.Socket.prototype.broadcast = function(msg)
{
	for (var i = 0; i < clients.length; i++) {
		var childSocket = clients[i];
		if (childSocket.getName() != this.getName()) {
			childSocket.printLine(msg);
		}
	}
};

net.createServer(function (socket) {
	clients.push(socket);

	socket.log('Connected!');

	socket.on('data', function (raw) {
		raw = raw.toString().trim();
		socket.log('Received data ' + raw.length + ' bytes');


		if (raw == 'getClients') {
			socket.printLine("Client list.");
			for (var i = 0; i < clients.length; i++) {
				var childSocket = clients[i];
				socket.printLine('-> ' + childSocket.getName());
			}
			socket.log('Send client list.');
			return;
		}

		if (raw == 'broadcast') {

			socket.broadcast('Test broadcast!!');
			socket.printLine("Broadcasted.");
			socket.log('Broadcasted.');
			return;
		}

		try {
			// do anythink to raw data blabla....
		} catch (e) {
			console.log(e);
			socket.printLine('Process raw data failed. View console log for more info');
		}
	});

	socket.on('end', function () {

		// Unset client from clients
		for (var i = 0; i < clients.length; i++) {
			var childSocket = clients[i];
			if (childSocket.getName() == socket.getName()) {
				clients.splice(i, 1);
			}
		}

		socket.log('Disconnect!');
	});

}).listen(config.server.port);

console.log('Listen on ' + config.server.port + '.');