tcp & udp

const net = require('net')
const server = net.createServer(socket => {
    socket.on('data', data => {
        console.log(data.toString())
        socket.write('你好')
    })

    socket.on('end', () => console.log('connection ended'))
    socket.write('welcome to tcp server')
})

server.listen(8124, () => console.log('listing to port 8124'))
// client test: telnet 127.0.0.1 8124

var net = require('net')
var client = net.connect({ port: 8124 }, () => {
    console.log('client connected')
    client.write('world!\r\n')
})

client.on('data', data => {
    console.log(data.toString())
    client.end()
})

const net = require('net')
const server = net.createServer(socket => {
  socket.write('echo server \r\n')
  socket.pipe(socket)
})

server.listen(1337, '127.0.0.1')

const dgram = require('dgram')
const server = dgram.createSocket('udp4')
server.on('message', (msg, rinfo) => {
  console.log("server got: " + msg + " from " + rinfo.address + ":" + rinfo.port)
})

server.on('listening', () => {
  var address = server.address()
  console.log('server listening' + address.address + ":" + address.port)
})

server.bind(41234)

const dgram = require('dgram')
const message = new Buffer('node.js in depth')
const client = dgram.createSocket('udp4')
client.send(message, 0, message.length, 41234, 'localhost', (err, bytes) => {
  client.close()
})

const http = require('http')
const server = http.createServer((req, res) => {
  res.writeHead(200, {'Content-Type': 'text/plain'})
  res.end('Hello World\n')
})
server.listen(1337)
console.log('listening to port 1337')

const http = require('http')
const options = {
  hostname: '127.0.0.1',
  port: 1337,
  path: '/',
  method: 'GET'
}

var req = http.request(options, res => {
  console.log('Status: ' + res.statusCode)
  console.log('Headers: ' + JSON.stringify(res.headers))
  res.setEncoding('utf8')
  res.on('data', chunk => console.log(chunk))
})

req.end()