Add,Modify and Delete Users and Groups in Ubuntu
You can start Users Administration Tool from System--->Administration--->Users and groups
Use the following command from terminal
Once it opens you should see similar to the following screen here you need to click on lock icon to do any changes
Now you will be prompted for the administrator password click on Authenticate. This is necessary because the changes done with this tool will affect the whole system.
Add a new user
After entering the administrator password in the above screen, the following window is displayed.Press the Add User button in the main dialogue
A new window will appear asking for the new user data. For adding a new user, you must provide at least the username and password (automatically generated, or by hand)
One more important field is profile here you can select what permission you want to provide this new user
Under User Privileges tab you can give what new user can do on this system
In Advanced tab you can provide home directory,shell used,Main group, user ID and a list of the secondary groups for the user, shell used, home directory and user ID are automatically guessed depending on the selected profile.
Once you created new user you should see similar to the following screen
Modify an existing user
If you want to modify an existing user select the user you want to modify and press the Properties button
A window similar to the following will appear with all the user data, allowing you to modify them.
Delete an existing user
If you want to delete an existing user or users select the user or users that you want to delete and press the Delete button in the Users tab. Due to the importance of this data, you will be asked for confirmation for every user you want to delete.For security reasons, the home directory of the deleted users will not be deleted so you can delete from home directory
Add a new group
If you want tp add a new group click on Manage groups
Now you should see similar to the following screen here click on Add Group button
A new window will appear asking for the new group data. For adding a new group, you must provide at least the group name and the group ID. Optionally you can specify the users that will belong to this group click on ok
Once added you should see your group similar to the following screen
Modify an existing group
Now select the group you want to modify in the groups dialogue and press the Properties button.
A window will appear with the group's data allowing you to modify it.
Delete an existing group
Select the group or groups that you want to delete in the groups dialogue and press the Delete button in the Groups tab. Due to the importance of this data, you will be asked for confirmation for every group you want to delete.