TypeError：使用Node.js fs.read（）的错误参数

Question

I'm trying to get fs.read() to work but running into some issue(s). Here is my fread.js script:

var fs = require('fs');

fs.open('test.txt', 'r', function (err, handle) {

    var f = handle;
    var b = new Buffer(100000);

    fs.read(f, b, 0, 100000, null, function (err, bytesRead) {
        console.log(b.toSting("utf8", 0, bytesRead));
        fs.close(f);
    });

});

Why do I get the following TypeError: Bad Argument error upon running it?

$ node fread.js 

fs.js:457
  binding.read(fd, buffer, offset, length, position, wrapper);
          ^
TypeError: Bad argument
    at Object.fs.read (fs.js:457:11)
    at /home/max/dev/livelessons/fread.js:8:5
    at Object.oncomplete (fs.js:107:15)

Answer 1

The problem was that I gave it the wrong file name. test.txt should have been text.txt . Doh!

Answer 2

You should check that fs.open() was successful first. Most likely err is set and handle is set to undefined, causing the "Bad Argument" error.