What is Node.js fs.Dirent.isBlockDevice() Method?

In this article, we will learn Node.js fs.Dirent.isBlockDevice() Method,This free Node.js tutorial for complete beginners will help you learn Node.js from scratch.

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The fs.Dirent.isBlockDevice() method is an inbuilt application programming interface of class fs.Dirent within File System module which is used to check if the particular dirent describes a block device or not.

Syntax:

const dirent.isBlockDevice()

Parameters: This method does not accept any parameter.

Return Value: This method returns true if the particular dirent describes the block device otherwise false.

Example 1: The below program illustrates the use of fs.dirent.isBlockDevice() method in Node.js:

Filename: index.js

javascript

// Node program to demonstrate the
// dirent.isBlockDevice() method
const fs = require('fs');
 
// Initiating async function
async function stop(path) {
 
    // Creating and initiating directory's
    // underlying resource handle
    const dir = await fs.promises.opendir(path);
 
    // Synchronously reading the directory's
    // underlying resource handle using
    // readSync() method
    for (let i = 0; i <= 3; i++) {
 
        // Checking if the particular dirent
        // is blocked device or not by using
        // isBlockDevice() method
        const value = (dir.readSync()).isBlockDevice();
 
        // Display the result
        console.log(dir.readSync());
        console.log(value);
 
    }
}
 
// Catching error
stop('./').catch(console.error);

Run the index.js file using the following command:

node index.js

Output:

Dirent { name: 'cert.cer', [Symbol(type)]: 1 }
false
Dirent { name: 'certificate1.cer', [Symbol(type)]: 1 }
false
Dirent { name: 'filename.txt', [Symbol(type)]: 1 }
false
Dirent { name: 'GFG.java', [Symbol(type)]: 1 }
false

Example 2: The below program illustrates the use of fs.dirent.isBlockDevice() method in Node.js:

Filename: index.js

javascript

// dirent.isBlockDevice() method
const fs = require('fs');
 
// Initiating async function
async function stop(path) {
 
    // Creating and initiating directory's
    // underlying resource handle
    const dir = await fs.promises
        .opendir(new URL('file:///F:/'));
 
    // Synchronously reading the directory's
    // underlying resource handle using
    // readSync() method
    for (let i = 0; i <= 3; i++) {
 
        // Checking if the particular
        // dirent is blocked device or not
        // by using isBlockDevice() method
        const value = (dir.readSync())
            .isBlockDevice();
 
        // Display the result
        console.log(dir.readSync());
        console.log(value);
    }
}
 
// Catching error
stop('./').catch(console.error);

Run the index.js file using the following command:

node index.js

Output:

Dirent { name: 'adonis_auth_api', [Symbol(type)]: 2 }
false
Dirent { name: 'Android Template', [Symbol(type)]: 2 }
false
Dirent { name: 'Calendar', [Symbol(type)]: 2 }
false
Dirent { name: 'first-app', [Symbol(type)]: 2 }
false

Note: The above program will not run on online JavaScript and script editor.

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/fs.html#fs_dirent_isblockdevice

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