CentOS / RHEL 7 : Users and Groups

What Users and Groups Are?

The control of users and groups is a core element of Red Hat Enterprise Linux system administration.

The user of the system is either a human being or an account used by specific applications identified by a unique numerical identification number called user ID(UID).

Users within a group can have read permissions, write permissions, execute permissions or any combination of read/write/execute permissions for files owned by that group.

A group is an organization unit tying users together for a common purpose, which can be reading permissions, writing permission, or executing permission for files owned by that group. Similar to UID, each group is associated with a group ID (GID).

1. To Add A New User [test is name of user]

#useradd test

2. To Remove User

#userdel test

 3. To Add group [sales is group name]

# groupadd sales

4. To Delete group [sales is group name]

#groupdel sales

5. To Add User In Group [test is name of user and sales is group name]

#gpasswd –a test sales

6. To Remove User In Group

#gpasswd –d test sales