Handle sockets in a different file node.js with expressjs

sockets.js

/* app.js */
var server = http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port ' + app.get('port'));
});


var io = require('./utils/sockets').listen(server); //for example

/* utils/sockets.js */
var socketio = require('socket.io');

module.exports.listen = function(app) {

    io = socketio.listen(app);
    io.set('log level', 0); //Set less log

    io.sockets.on('connection', function (socket) {
        
        socket.on('getSomething', function(datas) {
              //Broadcast only to client !
              io.sockets.socket(socket.id).emit('sendSomething', JSON.stringify(datas));
        });
   });

  return io;
}