commands from RHC* book giving error
 

doing an exercise on Setgid bit, and the lab has me creating a group called sdatagrp and adding 2 users to it

#groupadd -g 9999 sdatagrp --this works

#usermod -G ahgori sdatagrp
usermod: user 'sdatagrp' does not exist

I understand that when you create a user, they get added to a group same as their name, but creating a user just to make a group seems silly.


anyone know why this isn't working?

Edit: forgot to mention im using CentOS

You are using 'usermod' instead of 'useradd'. If user doesn't exist you can't modify it.

im trying to modify the existing user to be added to the group sdatagrp which i just created

when i use useradd, like this #useradd -g sdatagrp aghori
i get : user aghori already exists , if i do it the other way it just creates a user named sdatagrp and puts it in aghori group. not what i want.

which leads me to believe the book is correct in saying i need to use usermod

thanks very much

-G identifies
http://pic.dhe.ibm.com/infocenter/ai...%2Fusermod.htm