What is Node.js fs.filehandle.chown() Method?

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Node.js fs.filehandle.chown() Method - ❤️Node.js Tutorials In 2024

The fs.filehandle.chown() method is an inbuilt application programming interface of class fs.filehandle within File System module which is used to change the ownership of the particular file.

Syntax:

const filehandle.chown(uid, gid)

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

uid:: It represent the user id.
gid: It represent group identifiers.

Return Value: This method returns a pending promise that contain no value in it.

Below programs illustrates the use of fs.filehandle.chown() method.
Example 1: Filename: index.js

javascript

// Node.js program to demonstrate the 
// filehandle.chown() method
const fs = require('fs');
const fsPromises = fs.promises;
 
console.log("content of file before operation :- "
        + (fs.readFileSync('example.txt')));
 
// Initiating asynchronise function
async function funct() {
 
    // Initializing filehandle
    let filehandle = null;
 
    try {
 
        // Creating and initiating filehandle
        filehandle = await 
            fsPromises.open('example.txt', 'r+');
 
        // Modifying the file ownership
        // by using chown() method
        const prom = filehandle.chown(1, 1);
 
    } finally {
 
        if (filehandle) {
 
            // Close the file if it is opened.
            console.log("ownership is changed"
                        + " successfully");
 
            console.log("content of file after"
                + " operation :- " +
                (fs.readFileSync('example.txt')));
 
            await filehandle.close();
        }
    }
}
 
funct().catch(console.error);

Directory structure before running the program:

Directory structure after running the program:

Run index.js file using the following command:

node index.js

Output:

content of file before operation :- Content of example.txt file
ownership is changed successfully
content of file after operation :- Content of example.txt file

Example 2: Filename: index.js

javascript

// Node.js program to demonstrate the 
// filehandle.chown() method
const fs = require('fs');
const fsPromises = fs.promises;
 
// Data for the new file
let data = "This is a file containing "
        + "a collection of books.";
 
// Name of the file to be created
let file = "books.txt";
 
// Creating the new file 'books.txt'
fs.writeFile(file, data, (err) => {
 
    // Catching error
    if (err) {
        console.log(err);
    }
});
 
// Using fs.exists() method 
fs.exists(file, (exists) => {
    if (exists) {
        console.log("content of file"
            + " before operation :- " +
            (fs.readFileSync(file)));
    }
});
 
// Initiating asynchronise function
async function funct() {
 
    // Initializing filehandle
    let filehandle = null;
 
    try {
 
        // Creating and initiating 
        // filehandle
        filehandle = await 
            fsPromises.open(file, 'r+');
 
        // Modifying the file ownership
        // by using chown() method
        const prom = filehandle.chown(1, 1);
 
    } finally {
 
        if (filehandle) {
 
            // Close the file if it is opened.
            console.log("ownership is changed");
 
            console.log("content of file "
                + "after operation :- " +
                (fs.readFileSync(file)));
 
            await filehandle.close();
        }
    }
}
 
funct().catch(console.error);

Directory structure before running the program:

Directory structure after running the program:

Run index.js file using the following command:

node index.js

Output:

content of file before operation :- This is a file containing a collection of books.
ownership is changed
content of file after operation :- This is a file containing a collection of books.

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