Sunday, March 2, 2008

Removing Users From Groups In CentOS / RHEL / Fedora

Removing Users From Groups In CentOS / RHEL / Fedora In CLI

So many websites will explain how to add a user to a group, but if i need to remove a user from a group in the CLI how to do it, This is how..

If you don't know how to add a user to a group read the following tutorial.

http://tiny.cc/W0bzu

How to remove a user from a group.

I have not found any commands for this so I'll teach a manual method.

Assume there is a group call "group1" and there are three members in the group call "user1", "user2", "user3"

I want to remove "user2" from "group1"

1. The group details will be stored under two files call "group" and another call "gshadow", We'll examine the files first

# cat /etc/group

You'll find a line as follows

group1:x:503:user1,user2,user3

# cat /etc/gshadow

You'll find a line as follows

group1:!::user1,user2,user3

2. Now what we have to do is, manually remove "user2" from the "group1", Give the following command.

# vigr

The above command will open "/etc/group" file in VI text editor.

3. Use the down arrow key and go up to "group1:x:503:user1,user2,user3" line and press " i " to go to insert mode, and delete "user2" from the line, Now it'll look like this.

group1:x:503:user1,user3

Then press "esc" and type" :wq " to save and exit the file. It'll ask a question as follows,

You are using shadow groups on this system.
Would you like to edit /etc/gshadow now [y/n]?

Press " y " and press "enter"

Now it'll open "/etc/gshadow" file in VI text editor.

Use the down arrow key and go up to "group1:!::user1,user2,user3" line and press " i " to go to insert mode, and delete "user2" from the line, Now it'll look like this.

group1:!::user1,user3

Then press "esc" and type" :wq " to save and exit the file.

4. That's it, now the "user2" is removed from "group1"

This is another way to do it but you want be able to completely remove a user from the groups he/she belong to.

http://tiny.cc/zMm7x