使用fs.readFile（）读取由fs.createWriteStream（）创建的文件是否不合适？

Question

节点版本：v12.16.1os：Windows 7

最近，我尝试使用fs.readFile（）访问由fs.createWriteStream（）创建的日志文件，但仅获取它的第一行。但是，当我创建具有相同内容的测试文件并使用fs.readFile（）来获取它时，它就可以正常工作。仅仅是因为第一个文件是由fs.createWriteStream（）创建的吗？我也对此进行了一些测试：

//create a writeable stream
const fs = require('fs');
let output = fs.createWriteStream('./output.txt');

output.write('c1:1');
output.write('c1:2');
output.write('default:1');

//read the file synchronously
let read = fs.readFileSync('./output.txt','utf8');
console.log(`read the output file synchronously: \n${read}`);

//read the test file synchronously
let readTest = fs.readFileSync('./test.txt','utf8');
console.log(`read the test file synchronously: \n${readTest}`);

//read the file asynchronously
let readAsync = fs.readFile('./output.txt','utf8',(err,data)=>{
    console.log(`read the file asynchronously: \n${data}`);
});

//read the test file asynchronously
let readTestAsync = fs.readFile('./test.txt','utf8',(err,data)=>{
    console.log(`read the test file asynchronously: \n${data}`);
});

//read the file with fs.createReadStream
let stream = fs.createReadStream('./output.txt','utf8');

let readWithStream = "";

stream.on('data',(data)=>{
    readWithStream += data;
});

stream.on('end',(data)=>{
    console.log(`read the file with fs.createReadStream : \n${readWithStream}`);
});


//read the test file with fs.createReadStream
let streamTest = fs.createReadStream('./test.txt','utf8');

let readTestWithStream = "";

streamTest.on('data',(data)=>{
    readTestWithStream += data;
});

streamTest.on('end',(data)=>{
    console.log(`read the test file with fs.createReadStream : \n${readTestWithStream}`);
});

这是结果：

Answer 1

具有相同问题的朋友的新版本：

//create a writeable stream for our Console instance as stdout
const fs = require('fs');
let output = fs.createWriteStream('./output.txt');

output.write('c1:1\n');
output.write('c1:2\n');
output.write('default:1\n');
output.end(); //close the writable stream

setTimeout(readAfter,5000); //5s delay to ensure all the data has been writing into the disk and then read it

function readAfter(){
    //read the file synchronously
    let read = fs.readFileSync('./output.txt','utf8');
    console.log(`read the output file synchronously: \n${read}`);

    //read the test file synchronously
    let readTest = fs.readFileSync('./test.txt','utf8');
    console.log(`read the test file synchronously: \n${readTest}`);

    //read the file asynchronously
    let readAsync = fs.readFile('./output.txt','utf8',(err,data)=>{
        console.log(`read the file asynchronously: \n${data}`);
    });

    //read the test file asynchronously
    let readTestAsync = fs.readFile('./test.txt','utf8',(err,data)=>{
        console.log(`read the test file asynchronously: \n${data}`);
    });

    //read the file with fs.createReadStream
    let stream = fs.createReadStream('./output.txt','utf8');

    let readWithStream = "";

    stream.on('data',(data)=>{
        readWithStream += data;
    });

    stream.on('end',(data)=>{
        console.log(`read the file with fs.createReadStream : \n${readWithStream}`);
    });


    //read the test file with fs.createReadStream
    let streamTest = fs.createReadStream('./test.txt','utf8');

    let readTestWithStream = "";

    streamTest.on('data',(data)=>{
        readTestWithStream += data;
    });

    streamTest.on('end',(data)=>{
        console.log(`read the test file with fs.createReadStream : \n${readTestWithStream}`);
    });
};