To add user1

# useradd user1

This command will do the following:

• Create a home directory,/home/user1, for user1
• Add the configuration files from /etc/skel to the user home directory
• Assign the /bin/bash shell

To list the hidden files

# ls -a /home/user1

To assign a password to user1

# passwd user1

To delete user1 and the user1's home directory

# userdel -r user1

To assign user1 to the admin group

# usermod -G admin user1

To allow user1 full administrative

• Add user1 to the wheel group with this command

  # usermod -G wheel user1

• # vi /etc/sudoers

• Add the following line:

  user1    ALL=(ALL)       ALL

To add user2, user3 and user4 to the training group, and to allow them to share the /home/training directory:

1. # mkdir /home/training

2. # useradd user2; passwd user2
   # useradd user3; passwd user3
   # useradd user4; passwd user4
   

3. # vi /etc/group

4. Add the training group, give it a unique group id, and add user2, user3, and user4 to the group as follows:

   training,x,9999,user2,user3,user4

5. # chmod 2770 /home/training