nodejs achieve read the file

Today backend colleagues from work and wanted me to read the contents of a file. I think this is a small Manga, he immediately agreed.
I know this is nodejs read, but I want to, usually we have to be able to run from a service node server,
such as the following code

var http = require('http');
http.createServer(function(request,response){
    response.writeHead(200,{'Content-Type':'text/plain'});//200是服务器响应头部
    response.end('hello world!')
}).listen(8888);
console.log('在控制台打印出....http://127.0.0.1:8888/')

Print in the browser, running

but the file how to read it?
Nodejs have a special module, fs, fs module but will not play a service ah?
This time we will npm With the magic of the
first step:

npm init 
cnpm install --save fs

Write

//app.js
const fs = require('fs');
try {
  const data = fs.readFileSync('./rootca.pem', 'utf-8');
  // 等待操作结果返回，然后打印结果
  console.log(data);
} catch(e) {
  console.log('读取文件发生错误');

Run
node app.js
operating results for the

bingo completed my colleagues to help small busy
then I think my face inward, someone said to me, I thank you more embarrassed ah, I'm going to file written're welcome

const fs = require('fs');
var str = '不用谢';
// fs.writeFileSync('./rootca.pem',str,(err)=>{
//   if(err){
//     console.log('写入文件操作失败')
//   }else{
//     console.log('写入文件操作成功')
//   }
// })
try {
  const data = fs.readFileSync('./rootca.pem', 'utf-8');
  // 等待操作结果返回，然后打印结果
  console.log(data);
} catch(e) {
  console.log('读取文件发生错误');
}

We will find're welcome written into the file, but the file is rewritten

first come here, see next blog