We all know that Linux is a multi-user operating system, where multiple people can log in at once. So, at a glance, we see that there are users… Each user has a unique ID known as UID or User ID.
Groups are a mechanism to manage a collection of computer systems users. All users have an ID (commonly referred to as UID) and all groups have an ID (commonly referred to as a GID). Users may or may not be assigned to groups. Groups serve different purposes based on the permissions that an administrator defines. With group management and administration, we begin to see why and how Linux can be so powerful based on the permissions you can define in it.
#groupadd –help for more information or visit the man page for it.
-g = the group ID – let’s take a group called sales, its GID is 343 and we want it to be 205. We simply type in the following command to change the ID number and then sales will have Group ID 205.
Example #groupmod -g 205 sales
-n = change the group name – this will allow us to change the sales group to say global sales.
Example: #groupmod -n globalsales sales
Deleting Groups, is simple. Simply type out the following command #groupdel and then the group’s name you want to delete. Like so…