1.url、stream

1.url.parse('url')，解析结果注意query和search的区别。search比query多最前面的问号

2.url.format

url.format({
 protocol: 'http:',
 slashes: true,
 auth: null,
 host: 'www.imooc.com',
 port: null,
 hostname: 'www.imooc.com',
 hash: null,
 search: null,
 query: null,
 pathname: '/video/6710',
 path: '/video/6710',
 href: 'http://www.imooc.com/video/6710'
})

3.url.resolve

4.url.parse设置第二个参数为true可以将query解析成一个对象，设置第三个参数为true可以不写协议

5.stream

var readStream = fs.createReadStream('./xxx.js')
var writeStream = fs.createWriteStream('./xxx.js')

• 可读流的事件: data、readable、end、close、error

readStream.on('data',(chunk)=>{ console.log(chunk) })

• 可读流的方法: pause()、resume()

readStream.pause() readStream.resume()

• 写入流的事件 :drain

writeStream.on('drain',()=>{ })

• 写入流的方法:end()

writeStream.end()