NodeJs-fs模块

'use strict'
let fs = require("fs");
let path = require("path");
let fs2 = require('fs-extra');

//读文件
fs.readFile("a.txt", (err, data) =>{
    if(err){
        throw err;
    }

    console.log(data.toString());
});

//写文件
let data = "举头望明月，低头思故乡";
fs.writeFile("b.txt", data, (err)=>{
    if(err){
        throw err;
    }

});

//读文件夹
let target = "./test";
fs.readdir(target, (err, files)=>{
    //遍历数组
    files.forEach( f =>{
        // 判断当前的f到底是文件夹还是文件
        fs.stat(path.join(target, f), (err, stat)=>{
            if(err){
                throw err;
            }
            console.log(f + " : "+ stat.isDirectory());
        })
    });
});

// 删除文件
fs.unlink("test/a.txt", (err)=>{
    if(err){
        console.log("删除失败："+err);
    }else {
        console.log("删除成功");
    }
});

// 删除文件夹
fs.rmdir("test", (err) =>{
   console.log(err);
});

// 同步阻塞的方式来读取文件
let data = fs.readFileSync("async-demo.js");
console.log(data.toString());

// 删除非空文件夹
fs2.remove("test");

// 监视文件变化
fs.watchFile("a.txt", {interval: 500} , (current, previous)=>{
   console.log(" current mtime:" + current.mtime);
   console.log(" previous mtime:" + previous.mtime);
});