Socket.io

socket.io.js

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var port = process.env.PORT || 3000;

app.get('/', function(req, res){
    res.sendFile(__dirname + '/index.html');
});

app.get('/chat', function(req, res){
    res.sendFile(__dirname + '/chat.html');
});

var people = {};

io.on('connection', function(socket) {
    socket.on('online user', function(user) {
        people[user] = socket.id;
    });

    socket.on('chat message', function(msg, user) {
        socket.to(people[user]).emit('chat message', msg);
    });
});

http.listen(port, function(){
    console.log('listening on *:' + port);
});