Node.js fs.createWriteStream() Method

The createWriteStream() method is an inbuilt application programming interface of fs module which allows to quickly make a writable stream for the purpose of writing data to a file. This method may be a smarter option compared to methods like fs.writeFile when it comes to very large amounts of data.

Syntax:

fs.createWriteStream( path, options )

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

• path: This parameter holds the path of the file where to read the file. It can be String, Buffer or URL.
• options: It is an optional parameter that holds string or object.

Return Value: This method returns the fs.writeStream object.

Following example illustrates the createWriteStream() method in Node.js:

Example 1: This example uses fs.createWriteStream() method to write some content into the file.

Node.js

// Node.js program to demonstrate the
// fs.createWriteStream() method

// Include fs module
let fs = require('fs'),

// Use fs.createWriteStream() method
// to write the file
let writer = fs.createWriteStream('test_gfg.txt')

// Read and display the file data on console
writer.write('GeeksforGeeks');

Output:

test_gfg.txt file data:
GeeksforGeeks

Example 2:  Piping from readable streams.

Node.js

// Node.js program to demonstrate the
// fs.createWriteStream() method

// Include fs module
let fs = require('fs');

let writer = fs.createWriteStream('test_gfg.txt', {
        flags: 'w'
    });

// Use fs.createReadStream() method
// to read the file
let reader = fs.createReadStream('test_gfg.txt')
         .pipe(writer);

With writable streams such as the streams created with fs.createWriteStream, data can be piped from a readable stream.