This article explores various tips and things you might not know or have not encountered before relevant to Ubuntu 20.04 Focal Fossa.
We will cover here such tricks as:
- shortcuts for opening terminal on Ubuntu 20.04,
- starting GUI from command line,
- extracting a list of users on your Ubuntu 20.04 system,
- checking software version,
- enabling Adobe Flash Player on Google Chrome and on Firefox
and much more.
There is a variety of shortcuts for accessing terminal on Ubuntu 20.04 that we explore in the guide below. We also show you how to access terminal as root and how to copy and paste text into the terminal on Ubuntu 20.04.
In this section, we will show you some tricks and things you might not know about GUI. These will include disabling and enabling GUI on boot, starting GUI from command line, restarting GUI while logged in and allowing GUI root login on Ubuntu 20.04.
This section shows you a couple of tricks relevant to the GNOME desktop. These include removing the dock panel on Ubuntu 20.04, resetting your GNOME Desktop to Factory Default which put your desktop appearance and all settings, shortcuts, wallpapers and etc. to a factory default.
We’ll also be showing you how to take screenshots in Ubuntu 20.04 Focal Fossa. There are a few different utilities we can use to accomplish this task as seen in the article below.
We will now show you some native and alternative methods on how to suspend ( suspend to RAM ) and hibernate ( suspend to disk ) the Ubuntu 20.04 operating system. Additionally, we will describe how to extract a list of users on the Ubuntu 20.04 Focal Fossa Desktop/Server.
Packages and Software
Although Ubuntu’s default package archive contains some of the most common software people need, a lot of times it’s necessary to install a package using a PPA repository. No problem there, except these PPA repositories don’t remove themselves unless you do it manually. After a while, your system could be querying a lot of irrelevant PPA repositories every time you install or update software. We’ll show you below how to list and delete the PPA repositories on Ubuntu 20.04 Focal Fossa.
Next, we will show you how to enable/disable Universe, Multiverse and Restricted repositories and how to disable automatic updates on Ubuntu 20.04.
Finally, we will describe how to list installed packages and check software versions.
The Adobe Flash Player is a part of the Google Chrome browser hence no extra installation is required. However, the Flash Player is disabled by default as the Adobe Flash is now an obsolete technology and will be supported as part of Google Chrome browser only until December 2020.
In this section, we will show you how to enable Adobe flash player on Google Chrome and on Firefox.
Now we will check what graphic driver your system is currently using and what graphic card model is part of your Ubuntu 20.04 system’s hardware.
Next, we will look at how to disable the default Nouveau kernel driver and how to uninstall the NVIDIA drivers on Ubuntu 20.04 Focal Fossa Linux, hence switch back to the opensource Nouveau Nvidia drivers.
Moreover, we will see how to test the 3D acceleration by checking for FPS on Ubuntu 20.04 Focal Fossa using the Mesa utils and the Phoronix Test Suite.
Programming and Scripting
In this section we will show you how to install multiple versions of GCC and G++ compilers using the
apt install command. Furthermore, by use of the
update-alternatives tool you will learn how to easily switch between multiple GCC and G++ compiler versions and how to check the currently selected compiler version.
Similarly, you can follow the tutorial on switching between Python versions.
Another useful trick described below is how to run a script on startup on Ubuntu 20.04.
Ubuntu 20.04 uses systemd service manager to manage services which means to enable and disable services is an easy and straightforward task.
In this section we will first focus on listing and changing state for systemd services and unit files on Ubuntu 20.04. Then, we will describe how to start a service on boot of your system.
Then, we will show you how to change hostname and domain name on Ubuntu 20.04.
First, we will learn how to retrieve a local IP address, gateway and DNS server on Ubuntu 20.04 Focal Fossa using graphical user interface and terminal command line.
Then, we will show you how to temporarily or permanently disable IPv6 on Ubuntu 20.04 LTS Focal Fossa. IPv6, Internet Protocol version 6 is the most recent version of the Internet Protocol (IP).
We will also show you various ways of restarting network on Ubuntu 20.04 in this section.
For interested readers, we will describe how to switch back networking from NetPlan/CloudInit on Ubuntu 20.04 Focal Fossa Linux to now already obsolete networking managed via
Finally, you will learn how how to install
nmap port scanner on Ubuntu 20.04 Focal Fossa Linux and how to perform basic port scanning with this tool.
SSH stands for secure shell which allows encrypted remote login connections between client and server over an unsecure network. The below guide will provide you with information on how to enable ssh and how to enable SSH access for a root user on Ubuntu 20.04.
UFW is the handy and simple default firewall found on Ubuntu 20.04 Focal Fossa. As easy as it is to configure, you still need to know the proper syntax in order to edit it. In the guide below, we’ll show you how to list and delete individual firewall rules in UFW.
Then we show how to allow incoming traffic on any TCP or UDP port using Ubuntu 20.04 Focal Fossa Linux with UFW firewall.
Ubuntu 20.04 installation comes with a default blank root password. This is a security precaution since the user is never expected to login as the root user. For any privileged administration tasks the user is recommended to use the
sudo command. Setting a root password comes with risks, but we include the instructions on how to do it for the interested reader. Moreover, we will show you how to reset lost root or user password.
Additionally, you will learn how to configure
sudo without the password. Meaning that the
sudo command will not prompt you to enter password hence rendering your
sudo command completely password less.
This section includes some specific errors and instructions how to fix them.
We first include fixes to command not found errors for
make commands, such as:
ping linuxconfig.org bash: ping: command not found
Other errors that are commonly encountered are:
unable to locate package
unable to play file due the the missing decoder
the following signatures couldn't be verified
temporary failure resolving
We provide fixes to all these errors below.
In this section, we will see how to connect the Android Smartphone to KDE desktop on Ubuntu 20.04 Focal Fossa.
You will discover:
These are all our tricks and things you might not know. If you think this article is missing an important Ubuntu 20.04 trick or you find an error please send your feedback to our forum using the comments and discussion section on the bottom of this page.