How to administrate groups with the Unix / Linux gpasswd command

The gpasswd command is used to administer groups in Linux and Unix. It writes group information in /etc/group and /etc/gshadow.

Because the gpasswd command works with some files located in /etc, it needs to be used with root priviledges.

Any group can have group administrators, group members and a password. The passwords for groups aren’t used so much, because they can generate security issues, since a group password needs to be know by all the members of the group.

In this article I will show you how to use the gpasswd command in order to edit the group account information:

How to add user to group:

Syntax: gpasswd -a user group

I will add the user mike34 to the group naboo21

$ sudo gpasswd -a mike34 naboo21
Adding user mike34 to group naboo21

How to remove a user from a grup:

Syntax: gpasswd -d user group

I will remove the recently added user mike34 from the naboo21 group:

$ sudo passwd -d mike34 naboo21
Removing user mike34 from group naboo21

How to set a groups memberlist:

Syntax: gpasswd -M user1 user2 use99 group

$ sudo gpasswd -M mike1,mike2,mike3 naboo21
$ grep naboo21 /etc/group
naboo21::1043:mike1,mike2,mike3

This command is very usefull when you need to asign users to groups.

How to set an group administrator:

Syntax: gpasswd -A user group

The group administrator is the “group owner”, the user that can change group details.
I will set mike the group administrator.

$ su mike
$ gpasswd naboo21
gpasswd: Permission denied.
$ sudo gpasswd -A mike naboo21
$ gpasswd naboo21
Changing the password for group naboo21
New Password:
Re-enter new password:

Other usefull gpasswd features:

  • to set or change a password on a group, use sudo gpasswd group and insert a new password (twice)
  • to remove a group’s password use sudo gpasswd -r group

You can also use the useradd command to add users to groups.

Liked it? Take a second to support Geekster on Patreon!
Tagged with: , , , , ,
Posted in The Linux and Unix Articles!

Leave a Reply

Your email address will not be published. Required fields are marked *

*

Support LinuxG via Patreon
Support LinuxG.net on Patreon!
Subscribe

  

Subscribe to get the latest Linux news and how to guides directly on your e-mail!