Node.js 可读文件流未获取数据 [英] Node.js Readable file stream not getting data

问题描述

我正在尝试创建一个可读文件流，我可以从中读取单个字节.我正在使用下面的代码.

I'm attempting to create a Readable file stream that I can read individual bytes from. I'm using the code below.

var rs = fs.createReadStream(file).on('open', function() {
    var buff = rs.read(8); //Read first 8 bytes
    console.log(buff);
});

鉴于该文件是至少 8 个字节的现有文件，为什么我将空"作为输出?

Given that file is an existing file of at least 8 bytes, why am I getting 'null' as the output for this?

推荐答案

Event open 表示流已经初始化，并不表示可以从流中读取.您必须监听 readable 或 data 事件.

Event open means that stream has been initialized, it does not mean you can read from the stream. You would have to listen for either readable or data events.

var rs = fs.createReadStream(file);

rs.once('readable', function() {
    var buff = rs.read(8); //Read first 8 bytes only once
    console.log(buff.toString());
});

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