Node.js example #2 From Deploy 2010

SingingChat.js

var net = require('net'), fs = require('fs'), _ = require('./underscore-min')._;

// Our active connections
var connections = {};
var doc = fs.readFileSync('lyrics.txt', 'utf8').split(" ");
var word = 0;
var intervalId = null;

var sing = function() {
  if ((word >= doc.length || _.size(connections) == 0) && intervalId != null) {
    clearInterval(intervalId);
    word = 0;
    intervalId = null;
  } else {
    _(connections).each(function(receiver) { receiver.write(doc[word] + " "); });
    word++;
  }
}

var server = net.createServer(function(sock) {
  sock.setTimeout(0)
  sock.setEncoding("utf8");
  connections[sock.remotePort] = sock;  // Store a reference to the new client

  sock.on('data', function(data) {
    if (data.match(/^sing\n$/i) && !intervalId) {
      intervalId = setInterval(sing, 350); // Sing!
    } else {
      _.each(connections, function(receiver) {
        if (sock !== receiver) { receiver.write(data); } // Send new data to all other sockets
      });
    }
  });

  sock.on('close', function() { delete connections[this.remotePort]; });
});

server.listen(8124, "0.0.0.0");
console.log("Server started");