Node.js：使用fs.writeFile的奇怪符号“ ^ @”

Question

I've built and run Node.js on emmbed linux-os with MIPS 24K Little Endian CPU. Node.js version is v0.12.0. Everything works fine except when I use fs.writeFile, example code:

var fs = require('fs');
fs.writeFile("/tmp/test.txt","hello world!",'utf-8', function(err){
        if(err){
                return console.log(err);
        }
        console.log("saved");
});

Using vim to check this test.txt, the content is:

^@hello world!

Obviously, there's an undesireable symbol "^@" in the beginning of the written file.

So how does this problem happen and how to solve it?

Answer 1

First thing to do is to try retyping the hello world string, it may be that you've somehow inserted a NUL , or CTRL-@ character into it before the h . ECMAScript actually allows this, as NUL is not one of the characters forbidden to appear in a string literal.

You could check this before-hand by doing a hex dump of the source file to see what actual characters are in there.