<Node入门经典>读书笔记
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');
