What is the command for listing all users who are members of the admin group?

Question

I am looking for the name of the superusers list on Fedora. (On Ubuntu is seems to be "sudo".) I want to add one of the users to the superusers list.

The groups command only lists the groups of the current user.

Answer 1

There is only one superuser on Fedora and i.e. root. If you are looking for other user's who have the sudo privilege then you can look into /etc/sudoers file by executing command

visudo

Here you can add any user to have the sudo privilege, by adding the following line at the end of the /etc/sudoers file:

loginname ALL=(ALL) ALL

Answer 2

To list all available groups with users in them you can use

getent group

or just look the content of /etc/group file.

By the way, on ubuntu there is only one superuser too. It is root. All others just are allowed to use it privilleges via sudo. You can modify rules in /etc/sudoers via visudo as mentioned above, if sudo is installed. This is true for any main stream GNU/Linux distro.

Answer 3

To add a user to a group, such as wheel your can use the vigr command. You will also need to use vigr -s to update the shadow file.

Answer 4

“Superusers”, as in the users who can obtain administrative privileges, are the users who either know the root password or are authorized to execute commands as root with a mechanism such as sudo. These days, sudo is the most common and generally recommended mechanism.

There is no general rule to tell which users are allowed to gain privileges with sudo, it is a matter of convention. Look in the file /etc/sudoers for a line like

%sudo ALL = ALL

This means “Users in the group called sudo are allowed to run any command as any user”. Sometimes you'll see (ALL) after the equal sign: it's an optional way to restrict the line to work only on a particular machine (if you put a host name instead of ALL), which allows deploying the same configuration file to multiple machines with different intended privileges.

If there is such a line, you can add users to the sudo group:

adduser bob sudo

You can review who is a member of the sudo group by listing the group database:

getent group sudo

If there is no %sudo (or %admin or %wheel, as I said before the name is a matter of convention, and there can be more than one such entry), you can create one with addgroup and add the line to the sudoers file (use visudo to edit that file). Alternatively, instead of creating a group, you can add individual entries to the sudoers file (again, use visudo to edit this file):

bob ALL = ALL

Using a group makes management a little easier because you can see at a glance who is a member of this group.

Answer 5

It is perfectly well possible to have more than one user with root privileges, it is uncommon to create them though. You can create a user and assign it UID 0, just make sure the first line in /etc/passwd is always for root. For most users it is bad practice to do this though.

To list all users with root privileges:

grep -E '^[^:]*:[^:]*:0:' /etc/passwd