In this article, we will learn to add or remove users and giving them required permissions in Linux or Unix. As these operating systems are multi-user many users can have accounts on a single OS and can use resources simultaneously at a time.
So It is necessary to manage all the users or user groups. A system administrator manages all these user or user groups and their rights. We will use the command-line user interface to create, delete, and grant the root privileges to the created user.
Adding a new user
If currently you are logged in as root user or have superuser privileges. You can directly execute the command given below in your terminal
$ adduser new_user_name
Otherwise, if you do not have root access you can use the command below
$ sudo adduser new_user_name
It will ask to enter the new Unix password for the newuser, enter it. And again retype when it asks. Then it will ask other details about the user which are optional you can skip by hitting enter. Finally, confirm that the information provided is correct. Press y and then enter. Now a newuser has been created.
Grant sudo privileges to the new user
Sometimes we need to execute commands which require root access like installing or removing a package. By default created users will not have that access. So we will have to provide superuser privileges to the new user for that we will add created user to the sudo group. When we create a new user it automatically gets added to its own group. To check the group of a user we should use groups command as given below-
$ groups new_user
To get all groups in the system use the following command in your terminal.
$ getent group | cut -d: -f1
We will now add the created user to the sudo group. To add a new user into a group we should use usermod command. Syntax of which is given below:
$ usermod -aG group_name user_name
here we will add a new user with name newuser to the sudo group. Note that the newuser is now added in two groups that are newuser its own group and sudo.
Delete a user in Linux
If you no longer need that user account you can delete it by using the following command
$ sudo deluser newuser
It will not delete user data you can delete it later by using the following command
$ sudo deluser --remove-home newuser
Now I think you should have a basic understanding of creation, removal of the user, and adding that user into a group. If you have any query write to us in the comments below.