username Command in Linux With Examples

Linux as an operating system holds the capabilities of handling multiple users each with a username and a display name (Full Name). So it is important to keep a check on the users and their related information in order to maintain the integrity and security of the system. Whenever a user is added its information is stored in the “/etc/passwd” file. It keeps the username and other related details. Here are some commands to fetch username and its configurations from the Linux host.

There is no specific “username” command in Linux but there are other several sets of commands that let the user access the various users on the machine.

How to Check Username and Display Name in Linux

1. Using `whoami` Command to Check User Name in Linux

Type whoami in your terminal. This simple command instantly displays the username of the effective user currently running the shell.

whoami

whoami command to check username

2. Using `id` Command to Check User Name in Linux

id: This command basically prints the information of real and effective user or in other words the current user.

Syntax:

id

Example:

Use the id command followed by the username to print specific user information.

Syntax:

id username

Example:

3. Using getent Command to Check Username and Display Name in Linux

getent : This command fetches user information from database configured in /etc/nsswitch.conf. file which also includes passwd database.

Syntax:

getent passwd

Example:

Each line above has seven fields separated by colons which contains the following information-

• Username
• Encrypted Password
• User ID number(UID)
• User group ID number(GID)
• Full name of the user(GECOS)
• user home directory and
• Login shell respectively.

4. Using finger Command to Retrieve Username and Display Name

finger: It displays the current user’s real name along with the terminal name, write status, idle time, and login time.

Syntax:

finger

Example:

Use the finger command followed by the username to print specific user information.

Syntax:

finger username

Example:

5. Using lslogins Command to View Username and Display Name

It displays information about known users in the system. By default, it will list information about all the users in the system.

Syntax:

lslogins -u

Example:

6. Using `cat` Command to Check User Name in Linux

cat : This command fetches and prints user information from /etc/passwd/ file, where each line contains seven fields as in the output of getent and less command.

Syntax:

cat /etc/passwd/

Example:

user account information

7. Using `compgen` Command to Check User Name in Linux

This command also displays the name of all the users without any additional information. For more details refer the article compgen command in Linux

Syntax:

compgen -u

Example:

Note: One can use compgen -c command to list all commands available if he/she is not the admin on a Linux system and doesn’t have the sudo access.

8. Using `$USER` Command to Check User Name in Linux

The $USER environment variable holds your username’s value. Run echo $USER to retrieve it.

echo $USER

Check User Name

Conclusion

In this article, we explored multiple ways to check usernames and display names in Linux. While whoami, id, and compgen help identify usernames, commands like getent, finger, and lslogins provide both the username and the display name (Full Name in the GECOS field). These commands are essential for system administration, helping manage users efficiently. If you need to modify a user’s display name, use the chfn command.