How To Display All Users and Groups with a Command-Line?

In this article, we will discuss various methods to display all users and groups in your system using the command-line. This is a crucial task for system administrators who need to manage user accounts and permissions. We will cover three primary commands: compgen, cut, and getent.

Displaying Users and Groups Using compgen Command

The compgen command is used to display all the names that would appear if the tab key was pressed for completion. It can be used to list users and groups.

Displaying All Users

To display all users, run the following command:

compgen -u

The -u option tells compgen to list all user names.

Displaying All Groups

To display all groups, run the following command:

compgen -g

The -g option tells compgen to list all group names.

Displaying Users and Groups Using cut Command

The cut command is a utility that can extract sections from each line of input. It can be used to display users and groups by extracting information from system files.

Displaying All Users

To display all users, you can use the following command:

cut -d ":" -f 1 /etc/passwd

Here, -d ":" sets the delimiter to “:”, and -f 1 extracts the first field (username) from the /etc/passwd file, which contains user information. Note that this method may not display non-local accounts or accounts created by Docker mounts.

Displaying Users and Groups Using getent Command

The getent command displays entries from databases supported by the Name Service Switch libraries, which are configured in /etc/nsswitch.conf. It can be used to display both local and non-local accounts.

Displaying All Users

To display all users, run the following command:

getent passwd

Displaying All Groups

To display all groups, run the following command:

getent group

The getent command is recommended as it works for both local and non-local accounts. For more information about the getent command, you can refer to this link.

Conclusion

In summary, to display all users, you can use either compgen -u, cut -d ":" -f 1 /etc/passwd, or getent passwd. To display all groups, you can use either compgen -g, getent group, or cut -d ":" -f 1 /etc/group. Each command has its benefits and drawbacks, so choose the one that best fits your needs.

Remember, managing users and groups is a critical part of system administration. Understanding these commands will help you keep track of all users and groups in your system, making your job easier and more efficient.