1-module.js

function soma (a, b) {
    return a + b
}

module.exports = soma

2-eventemitter.js

var EventEmitter = require('events').EventEmitter

var dog = new EventEmitter()

dog.on('bark', function () {
    console.log('WOOF')
})

setInterval(function(){
    dog.emit('bark')
}, 1000)

3-stream.js

// 1. stdin
process.stdin.on('data', function (data) {
    console.log(data.toString())
})

// 2. fs
var fs = require('fs')
  , stream = fs.createReadStream('cats.txt')
  
stream.on('data', function (data) {
    console.log(data.toString().toUpperCase())
})

// 3. pipe
stream.pipe(process.stdout)

4-http.js

var http = require('http')

// Simple write() to stream

var server = http.createServer()

server.on('request', function (req, res) {
    res.write('hello')
    res.end()
})

server.listen(8881)
console.log('listening on port 8881')

5-http.js

var http = require('http')

// inspecting request properties

var server = http.createServer()

server.on('request', function (req, res) {
    console.log(req.headers)
    res.write(req.url)
    res.end()
})

server.listen(8882)
console.log('listening on port 8882')

6-http.js

var http = require('http')
  , fs   = require('fs')

// file streaming

var server = http.createServer()

server.on('request', function (req, res) {
    fs.createReadStream('../cats.txt').pipe(res)
})

server.listen(8883)
console.log('listening on port 8883')

7-app.js

var express = require('express')

// Express com logger, router e static

var app = express()

app.configure(function (){
    app.use(express.logger('dev'))
    app.use(app.router)
    app.use(express.static(__dirname + "/public"))
})

app.get('/', function (req, res) {
    res.end('index')
})

app.listen('8888')
console.log('listening on port 8888')

8-app.js

var express = require('express')
  , hbs     = require('express3-handlebars')

// Express with handlebars templates

var app = express()

app.configure(function (){
    app.engine('hbs', hbs())
    app.set('view engine', 'hbs')
    app.use(express.logger('dev'))
    app.use(app.router)
    app.use(express.static(__dirname + "/public"))
    if (app.get('env') === 'development') {
        app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
    }
})

app.get('/', function (req, res) {
    // res.end('index')
    res.render('index')
})

app.get('/hello/:name', function (req, res) {
    res.render('hello', { name: req.params.name })
})

app.listen('8888')
console.log('listening on port 8888')

app-interval-pause.js

var http    = require('http')
  , fs      = require('fs')
  , express = require('express')
  , hbs     = require('express3-handlebars')
  , sio     = require('socket.io')
  
// socket.io + client-side events + pause stream

var app = express()
  , server = http.createServer(app)
  , io = sio.listen(server)

app.configure(function (){
    app.engine('hbs', hbs())
    app.set('view engine', 'hbs')
    app.use(express.logger('dev'))
    app.use(app.router)

    app.use(express.static(__dirname + "/public"))

    if (app.get('env') === 'development') {
        app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
    }
})

app.get('/', function (req, res) {
    res.render('typewriter')
})

io.sockets.on('connection', function (socket) {

    var stream = fs.createReadStream('../cats.txt')
      , chunk
      , reading = true

    stream.setEncoding('utf8')

    function read () {
        chunk = stream.read(1)
        if (chunk) {
            socket.emit('char', chunk)
            if (reading) {
                setTimeout(read, 100)
            }
        }
    }

    stream.pause()
    stream.on('readable', read)

    socket.on('pause', function () {
        reading = false
    })

    socket.on('continue', function () {
        reading = true
        read()
    })

})

server.listen('8888')
console.log('listening on port 8888')

app-interval.js

var http    = require('http')
  , fs      = require('fs')
  , express = require('express')
  , hbs     = require('express3-handlebars')
  , sio     = require('socket.io')
  
// socket.io + file reading

var app = express()
  , server = http.createServer(app)
  , io = sio.listen(server)

app.configure(function (){
    app.engine('hbs', hbs())
    app.set('view engine', 'hbs')
    app.use(express.logger('dev'))
    app.use(app.router)

    app.use(express.static(__dirname + "/public"))

    if (app.get('env') === 'development') {
        app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
    }
})

app.get('/', function (req, res) {
    res.render('typewriter')
})

io.sockets.on('connection', function (socket) {

    var stream = fs.createReadStream('../cats.txt')
      , chunk

    stream.setEncoding('utf8')

    function read () {
        chunk = stream.read(1)
        if (chunk) {
          socket.emit('char', chunk)
          setTimeout(read, 200)
        }
    }

    stream.pause()
    stream.on('readable', read)

})

server.listen('8888')
console.log('listening on port 8888')

app.js

var http    = require('http')
  , express = require('express')
  , hbs     = require('express3-handlebars')
  , sio     = require('socket.io')
  
// simple socket.io demo

var app = express()
  , server = http.createServer(app)
  , io = sio.listen(server)

app.configure(function (){
    app.engine('hbs', hbs())
    app.set('view engine', 'hbs')
    app.use(express.logger('dev'))
    app.use(app.router)

    app.use(express.static(__dirname + "/public"))

    if (app.get('env') === 'development') {
        app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
    }
})

app.get('/', function (req, res) {
    res.render('socketio')
})

io.sockets.on('connection', function (socket) {
    var counter = 0
    var interval = setInterval(function(){
        socket.emit('tick', counter)
        counter++
    }, 500)

    socket.on('disconnect', function () {
        clearInterval(interval)
    })
})

server.listen('8888')
console.log('listening on port 8888')