Objective
Install and use the whois command in Linux.
Distributions
This guide covers Ubuntu, Debian, Fedora, OpenSUSE, and Arch Linux.
Requirements
A working install of any of the supported distributions with root privileges.
Conventions
- # – requires given linux command to be executed with root privileges either directly as a root user or by use of
sudocommand - $ – given linux command to be executed as a regular non-privileged user
Introduction
Whois is a simple, yet powerful, tool that allows you to see information about a specific domain name or IP address. You can use it to see things like contact information, nameservers, and domain registration information.
Whois is an older core Unix utility, so it’s available on every distribution.
Installing Whois
Ubuntu/Debian
$ sudo apt install whois
Fedora
# dnf install whois
OpenSUSE
# zypper in whois
Arch Linux
# pacman -S whois
Using Whois
Whois is dead simple to use in its most basic form. Open a terminal, type whois, and give it a domain name to look up.
$ whois linuxconfig.org
Whois will spit out a bunch of information about the site that you’re looking up. The readout will always start with information about the domain itself. Then, it’ll progress to information about the domain registrar and information about when the domain was registered and when it’ll expire.
Depending on the domain name, you may see admin and technical contact information. This information is provided in case of an issue with the site. You can contact the site administrator or a technical person running to site to report the issue or get help.
You might also see a bunch of information saying that the site is “Whois guard protected” like the example above. That individual paid to have their information hidden from whois searches.
You can also use whois to search for an IP address. The information provided for IPs is different from what you get with a domain. The IP scan will tell you who owns the server and how to contact that company.
You can see all of the flags that whois offers with the man page or the --help flag, but you probably won’t ever need them.
Closing Thoughts
Whois is an excellent tool for finding out information about a website or the server hosting it. It’s a great way to get contact information or research domain names that you’d like to purchase. It also helps when reporting technical issues with a site.
