I am using fs.createReadStream and pipe to copy file. The source file has been deleted, the file stream will exist?
<p>I copy the files in this way, in the process of copying files deleted the source files, but also can copy success. I want to know why you will be successful? This file has been deleted, the file stream will exist?</p>

<pre><code>var fs=require('fs');
var rOption={
    flags:"r",
    encoding:null,
    mode:0666
}

var wOption = {
    flags: 'a',
    encoding: null,
    mode: 0666
}

var fileReadStream=fs.createReadStream('file1.rar',rOption);
var fileWriteStream = fs.createWriteStream('file2.rar',wOption);

fileReadStream.on('data',function(data){
    fileWriteStream.write(data);
});

fileReadStream.on('error',function(err){
    console.log(err)
});

fileReadStream.on('end',function(){
    console.log("readStream end");
    fileWriteStream.end();
});
</code></pre>