读书笔记

时间：2021-09-04 18:19:26

最近在读<Node入门经典>, 之前没有做笔记, 今天开始把看过自己又写了的代码放这里以免忘记.

express

var express = require('express')

var app = express()

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

  res.send('Hello World')

})

app.listen(3000)

route

var http = require('http');

var url = require('url');

http.createServer(function(req,res){

	var name = url.parse(req.url).pathname;

	if (name === '/'){

		res.writeHead(200,{

			'Content-Type':'text/plain'

		});

		res.end('home page');

	}

	else if (name === '/about'){

		res.writeHead(200,{

			'Content-Type':'text/plain'

		});

		res.end('about me');

	}

	else if (name === '/redirect')

	{

		res.writeHead(301,{

		'location': 'http://www.baidu.com'

		});

		res.end();

	}

	else{

		res.writeHead(404,{

			'Content-Type':'text/plain'

		});

		res.end('page not find');

	}	

}).listen(3000, "127.0.0.1");

console.log('server start');

socket.io

var app = require('express')();

var http = require('http').Server(app);

var io = require('socket.io')(http);

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

  res.sendfile('index2.html');

});

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

  console.log('a user connected');

  socket.emit('chat message', {text:'hi'});

  socket.on('disconnect', function(){

    console.log('user disconnected');

  });

  socket.on('chat message', function(msg){

    console.log('message: ' + msg);

  });

});

http.listen(3000, function(){

  console.log('listening on *:3000');

});
<!doctype html>

<html>

  <head>

    <title>Socket.IO chat</title>

  </head>

  <body>

    <p id='count'></p>

    <script src="/socket.io/socket.io.js"></script>

    <script>

      var socket = io();

      var count = document.getElementById('count');

      socket.on('chat message', function(data){

        count.innerHTML = data.text;

      });

</script>

  </body>

</html>

json

var http = require('http');

var obj = {

	name:'green',

	sur:'abcd'

};

console.log(obj);

var json = JSON.stringify(obj);

console.log(json);

var ori = JSON.parse(json);

console.log(ori);

spawn

var spawn = require('child_process').spawn;

var ping = spawn('ping', ['www.baidu.com']);

ping.stdout.setEncoding('utf8');

ping.stdout.on('data', function(data){

	console.log(data);

});

ping.on('exit', function(code, signal){

	console.log(code,  ' ', signal);

	process.exit(0);

});

setInterval(function(){

	ping.kill('SIGINT');

},	2000);

cluster

var cluster = require('cluster');

var http = require('http');

var cpus = 4;

if (cluster.isMaster){

	console.log('master start at ' + process.pid);

	for (var i = 0; i < cpus; ++i ){

		cluster.fork();

	}

	cluster.on('death', function(worker){

		console.log('die: ' + woker.pid);

		cluster.fork();

	});

}

else{

	console.log('worker start ' + process.pid);

events

var eventEm = require('events').EventEmitter;

var myEvent = new eventEm();

myEvent.on('message', function(data){

	console.log(data);

});

myEvent.on('destroy', function(){

	console.log('destroyed');

});

myEvent.emit('message','show message');

setTimeout(function(){

	myEvent.emit('destroy');

}, 1000);

stream

var http = require('http');

var fs = require('fs');

http.createServer(function(req,res){

	var mp3 = 'abc.mp3';

	var stat = fs.statSync(mp3);

	res.writeHead(200,

	{

		'Content-Type':'audio/mpeg',

		'Content-Length': stat.size

	});

	var readSteam = fs.createReadStream(mp3);

	readSteam.pipe(res);

}).listen(3000, "127.0.0.1");

console.log('server start');

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