WHOIS Lookup gives you the ability to look up any generic domain name. This will display all of the details associated with the site as well as the technical contact which includes your domain registrar.

Before you can use, simply install the whois package

root@test-VirtualBox:/# apt-get install whois

Here is a simple text below, this will output information off google.

root@test-VirtualBox:/# whois google.de

This occurs because you are using a normal user account to run the installation. Simply install it using the sudo to install any package as a root user.

sudo apt-get update && sudo apt-get upgrade

The update and upgrade of the system will run now without errors

These commands might be different from the commands used in your Linux distribution. For Ubuntu: Use the commands below.

sudo apt-get autoremove
sudo apt-get clean
sudo apt-get autoclean

These commands are needed to remove packages (dependencies) laying on the system after a particular package has been uninstalled.