stream演示

本篇文章将介绍nodejs中stream文件流相关操作。

文件拷贝

const fs = require('fs')
const path = require('path')
// 文件路径
const filename = path.resolve(__dirname, 'data.txt')
const backFile = path.resolve(__dirname, 'back.txt')

// 创建读取流
const readStream = fs.createReadStream(filename)
// 创建写入流
const writeStream = fs.createWriteStream(backFile)

// 执行拷贝：pipe（不是一次性拷贝，而是一点点写入）
readStream.pipe(writeStream)

// 监听数据拷贝状态
readStream.on('end', () => {
  console.log('拷贝完成')
})

读写网络日志

将每次访问的GET请求日志写入到文件。

const fs = require('fs')
const path = require('path')
const http = require('http')

const logFile = path.resolve(__dirname,'data.txt')

// 创建server
const server = http.createServer((req, res) => {
  const method = req.method 
  if (method === 'GET') {
    const readStream= fs.createReadStream(logFile)
    // 将本地文件内容写入到res中去
    readStream.pipe(res)
  }
})

// 监听端口
server.listen(8000, () => {
  console.log('监听端口8000的GET请求...')
})