User Management

Useradd - Adding a new user

Options:

• -d home directory
• -s starting program (shell)
• -p password
• -g (primary group assigned to the users)
• -G (Other groups the user belongs to)
• -m (Create the user's home directory

Example: To add a new user with

• a primary group of users
• a second group mgmt
• starting shell /bin/bash
• password of xxxx
• home directory of vishal
• create home directory
• a login name of vishal                                                                                                                   
  
  In Detail :-  useradd -gusers -Gmgmt -s/bin/shell -pxxxx -d/home/vishal -m vishal                                                                                                                                                        

Usermod - Modifying existing user

Options:

• -d home directory
• -s starting program (shell)
• -p password
• -g (primary group assigned to the users)
• -G (Other groups the user belongs to)

Example: To add the group 'others' to the user vishal

Userdel - Deleting a user

Options:

• -r (remove home directory)

Example: To remove the user 'vishal' and his home directory

userdel -r vishal

Passwd - User's Password

Options:

• user's name (Only required if you are root and want to change another user's password)

Example: To change the password for the account you are currently logged in as...

passwd
Enter existing password
Enter new password
Enter new password again (to validate)

Example: To change the password for the user 'roger' (only you are logged in as root)...

passwd vishal
Enter existing password (can be either vishal's password or root's password)
Enter new password
Enter new password again (to validate)

su - Switch User

To switch to another user, use the su command. This is most commonly used to switch to the root account.

Example: To switch to root account...
su
Enter root's passwd

Example: To switch to the user 'vishal'...
su roger
Enter vishal's or root's passwd

To return to original user, enter exit