Node.js

The fs.rename() method is used to asynchronously rename a file at the given old path to a given new path.

It will overwrite the destination file if it already exists.

Syntax:

fs.rename( oldPath, newPath, callback )

Parameters: This method accept three parameters as mentioned above and described below:

oldPath: Path to the file whose name is to be changed. It can be a string, buffer or URL.

newPath: The new file path you would like to create. It can be a string, buffer or URL.

callback: It is the function that would be called when the method is executed. It has an optional argument for showing any error that occurs during the process. (If there is no error, error object holds null value)

Example

I called the file renamefile.js

// include file system module
var fs = require('fs');
 
//rename the file
fs.rename('sample.txt', 'sample_new.txt', function (err) {
  if (err) throw err;
  console.log('File Renamed.');
});

Open a node.js command prompt and run the program like node renamefile.js

This was the output of my file

C:\Users\user\nodejs>node renamefile.js
File Renamed.

Links

Code is in github

https://github.com/programmershelp/maxjavascript/tree/main/nodejs

In this example we show how to read a file in node.js

Following is a basic guide to reading the content of a file in Node.js.

You need to include the File System built-in module into your Node.js program. Like this.

var fs = require('fs');

You then read the file using the readFile() function.

fs.readFile('',)

The Callback function is provided as an argument to thr readFile function.

When the reading of the file is completed, the call back function is called with err and data.

You create a sample file, in this example sample.txt with some content in it. In this example the text file is in the same location as node.js example program

Example

I called the file readfile.js

// include file system module
var fs = require('fs');
 
// read the sample text file
fs.readFile('sample.txt',
    // callback function that is called when reading file is done
    function(err, data) {       
        if (err) throw err;
        // data is a buffer containing file content
        console.log(data.toString('utf8'))
});

Open a node.js command prompt and run the program like node readfile.js

This was the output of my file

C:\Users\user\nodejs>node readfile.js
sample text in the file