Node.js fs.filehandle.chown() Method
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
// 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
// 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
