Node.js | os.userInfo() Method

The os.userInfo() method is an inbuilt application programming interface of the os module which is used to get the information of currently effective user.

Syntax: 

os.userInfo( options )

Parameters: This method accepts single parameter options which is optional parameter. It specifies the process options to be passed, and an object which contains encoding as a parameter returns. 

• encoding: It specifies the character encoding for returned data. If it is set to 'buffer', then username, shell, homedir values will be buffer instances. Default value is 'utf8'.

Return Value: It returns an object that specifies the information about the current effective user, which contains username, uid, gid, shell, homedir like values.

Note: On POSIX platform, this is generally a subset of password file contains username, uid, gid, shell, and homedir. Windows shell is set to null and uid, gid are -1.

Below examples illustrate the use of os.userInfo() in Node.js:

Example 1: 

// Node.js program to demonstrate the   
// os.userInfo() Method

// Allocating os module
const os = require('os');

// Printing os.userInfo() values
try {

    // Printing user information
    console.log(os.userInfo());
} catch (err) {
  
    // Printing if any exception occurs
    console.log(": error occurred" + err);
}

Output: 

{ uid: -1,
  gid: -1,
  username: 'gekcho',
  homedir: 'C:\\Users\\gekcho',
  shell: null }

Example 2: 

// Node.js program to demonstrate the   
// os.userInfo() Method

// Allocating os module
const os = require('os');

// Printing os.userInfo()
try{

    // Setting options for os.userInfo()
    // method
    var options = {
        encoding: 'buffer'
    };

    // Printing user information
    console.log(os.userInfo(options));
} catch(err){

    // Printing exception if any
    console.log(": error occurred" + err);
} 

Output: 

{ uid: -1,
  gid: -1,
  username: <Buffer 6d 75 6b 75 6c>,
  homedir: <Buffer 43 3a 5c 55 73 65 72 73 5c 6d 75 6b 75 6c>,
  shell: null }

Note: The above program will compile and run by using the node filename.js command.

Reference: https://nodejs.org/api/os.html#os_os_userinfo_options