How to Show Users in Ubuntu

Ben
Ben
@benjislab

Ubuntu, a popular Linux distribution, is well-known for its user-friendly interface and robust performance. Whether you're a system administrator managing multiple users or a developer curious about the user accounts on your system, knowing how to display user information is essential. This guide will walk you through various methods to show users in Ubuntu, providing you with the insights you need to manage your system effectively.

Introduction to User Management in Ubuntu

User management is a crucial aspect of maintaining an Ubuntu system. It involves creating, modifying, and deleting user accounts, each of which has specific permissions and capabilities. Understanding how to view these user accounts is the first step in effective user management.

Method 1: Using the getent Command

The getent command displays entries from databases supported by the Name Service Switch libraries, which include the passwd database where user account information is stored.

  • To show all users: Open a terminal and type the following command:
getent passwd

This command lists all user accounts, including system accounts, showing their login name, encrypted password (usually just an x), user ID (UID), group ID (GID), user ID info (such as the full name), home directory, and shell.

  • To filter human users: System accounts typically have UIDs below 1000. You can filter for human users (usually with UIDs starting from 1000) by combining getent with awk:
getent passwd | awk -F:  '$3 >= 1000 {print $1}'

This command will display the usernames of human users on the system.

Method 2: Using the compgen Command

The compgen command is a bash built-in that allows you to generate possible completion matches for a word. It can be used to list users by querying bash completion for usernames.

  • To show all users: In your terminal, execute:
compgen -u

This simple command outputs the list of all usernames registered on the Ubuntu system.

Method 3: Viewing the /etc/passwd File

The /etc/passwd file contains one line for each user account, providing basic user attributes.

  • To view user accounts: Use a command line text viewer like cat or less:
cat  /etc/passwd

Or:

less /etc/passwd

This will display the contents of the /etc/passwd file, where you can see all user accounts. The format is the same as the output of getent passwd.

Conclusion

Understanding how to show users in Ubuntu is a fundamental skill for anyone managing an Ubuntu system. Whether you're using getent, compgen, or directly viewing the /etc/passwd file, these tools offer powerful ways to access and manage user information. With this knowledge, you can ensure that your Ubuntu system is properly managed, securing it against unauthorized access and optimizing it for the needs of its legitimate users.