index.js

var express = require('express');
var http = require('http');
 
var socketio = require('socket.io');
 
var app = express();
var server = http.Server(app);
var io = socketio(server);
server.listen(3001);
 
io.sockets.on('connection', function (socket) {
    console.log('A new user connected!');
    socket.emit('info', { msg: 'The world is round, there is no up or down.' });
});

↳ node
> var client = require('socket.io-client');
> var s = client('http://localhost:3001').on('connect', function(){ console.log('hi');});
undefined
> hi
^D
↳ curl localhost:3001/socket.io/socket.io.js
!function(e){if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),f.io=e()}}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);throw new Error("Cannot find module '"+o+"'")}var f=n[o]={exports:{}};t[o][0].call(f.exports,function(e){var n=t[o][1][e];return s(n?n:e)},f,f.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(_dereq_,module,exports){

module etc....