Node.js fs.fchown() Function Last Updated : 08 Oct, 2021 Comments Improve Suggest changes Like Article Like Report The fs.fchown() method is used to change the owner and group of the given file descriptor. The function accepts a user id and group id that can be used to set the respective owner and group. It has a callback function that returns any error that may occur if the function fails. Syntax: fs.fchown( fd, uid, gid, callback ) Parameters: This method accepts four parameters as mentioned above and described below: fd: It is an integer which denotes the file descriptor of the file of which the owner and group has to be changed. uid: It is a number that denotes the user id that corresponds to the owner to be set. gid: It is a number that denotes the group id that corresponds to the group to be set. callback: It is a function that would be called when the method is executed. err: It is an error that would be thrown if the method fails. Below examples illustrate the fs.fchown() method in Node.js: Example 1: This example shows the setting of the owner. javascript // Node.js program to demonstrate the // fs.fchown() method // Import the filesystem module const fs = require('fs'); let fd = fs.openSync("example_file.txt", "r"); // Set the owner to a new one keeping the group same // New owner is "geek" with user id 1027 // The old group is "xubuntu" with group id 999 fs.fchown(fd, 1027, 999, (error) => { if (error) console.log("Error Code:", error); else console.log("uid and gid set successfully"); }); Before Running the Code: xubuntu@xubuntu: ~/Desktop/fs-fchown$ ls -l total 8 -rw-rw--w- 1 xubuntu xubuntu 4 Apr 26 02:08 example_file.txt -rw-rw-r-- 1 xubuntu xubuntu 290 Apr 26 02:08 index.js Output of the Code: Given uid and gid set successfully After Running the Code: xubuntu@xubuntu: ~/Desktop/fs-fchown$ ls -l total 8 -rw-rw--w- 1 geek xubuntu 4 Apr 26 02:08 example_file.txt -rw-rw-r-- 1 xubuntu xubuntu 290 Apr 26 02:08 index.js Example 2: This example shows the setting of the group. javascript // Node.js program to demonstrate the // fs.fchown() method // Import the filesystem module const fs = require('fs'); let fd = fs.openSync("example_file.txt", "r"); // Set the owner to a new one keeping the group same // New owner is "raj" with user id 1025 // New group is "author" with group id 1031 fs.fchown(fd, 1025, 1031, (error) => { if (error) console.log("Error Code:", error); else console.log("uid and gid set successfully"); }); Before Running the Code: xubuntu@xubuntu: ~/Desktop/fs-fchown$ ls -l total 8 -rw-rw--w- 1 xubuntu xubuntu 4 Apr 26 02:08 example_file.txt -rw-rw-r-- 1 xubuntu xubuntu 290 Apr 26 02:08 index.js Output of the Code: Given uid and gid set successfully After Running the Code: xubuntu@xubuntu: ~/Desktop/fs-fchown$ ls -l total 8 -rw-rw--w- 1 raj author 4 Apr 26 02:08 example_file.txt -rw-rw-r-- 1 xubuntu xubuntu 290 Apr 26 02:08 index.js Reference: https://nodejs.org/api/fs.html#fs_fs_fchown_fd_uid_gid_callback Comment More infoAdvertise with us S sayantanm19 Follow Improve Article Tags : JavaScript Web Technologies Node.js Node.js-fs-module Similar Reads Node JS fs.readFile() Method ​In Node.js, the fs.readFile() method is a fundamental tool for reading files asynchronously, allowing your application to remain responsive while accessing file data. 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