text: /**
   * Created by 14486 on 2019/3/11.
   * 一: stream  流模块
       边读取边使用  这样等待的时间会更短
       我们用fs演示
       let fs = require("fs");
       let read = fs.createReadStream("1.txt");
       read.setEncoding("utf8");
       read.on("data",() => {// 监听 让流体变成动态的   read.resume()
              console.log(data);
              console.log(1);
       })
       read.on("end",() => {
          console.log("读取结束");
       })
       let write = fs.createWriteStream("3.txt");
       read.pipe(write); 通过管道完成文件的复制 也可以让流体变成动态的;
   另一种方式
       let Readable = require("stream").Readable;
       let rs = new Readable();
       rs.setEncoding("utf8");
       rs.push(2);
       rs.push(3);
       rs.push(null);
       let write = fs.createWriteStream("4.txt");
       rs.pipe(write);
   */
  let fs = require("fs");
  