Node.js fs.createReadStream() Method

The createReadStream() method is an inbuilt application programming interface of fs module which allow you to open up a file/stream and read the data present in it.
Syntax:

fs.createReadStream( 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.ReadStream object.
Below examples illustrate the createReadStream() method in Node.js:
Example 1:

javascript

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

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

// Use fs.createReadStream() method
// to read the file
reader = fs.createReadStream('input.txt');

// Read and display the file data on console
reader.on('data', function (chunk) {
    console.log(chunk.toString());
});

Output:

input.txt file data:
GeeksforGeeks: A computer science portal for geeks

Example 2:

javascript

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

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

// Use fs.createReadStream() method
// to read the file
reader = fs.createReadStream('input.txt', {
    flag: 'a+',
    encoding: 'UTF-8',
    start: 5,
    end: 64,
    highWaterMark: 16
});

// Read and display the file data on console
reader.on('data', function (chunk) {
    console.log(chunk);
});

Output:

forGeeks: A comp
uter science por
tal for geeks

Reference: https://nodejs.org/api/fs.html#fs_fs_createreadstream_path_options