Roel Van de Paar, Author at Linux Tutorials

VNC Remote-Screen Utilities for Linux

8 April 2021 by Roel Van de Paar

If you manage more than one computer, you may have wanted, at one point or another, a “remote keyboard,” a “remote mouse,” and a “remote screen” for that far-away computer, even if it is just up or down the stairs in your house.

VNC (Virtual network computing) can help here. Think about it as your screen, a keyboard, and a mouse at a remote workstation, controlled via the network and quite usable in terms of speed, even on somewhat slower connections.

A VNC setup usually consists of two or more computers, where the computers which need to be remotely controlled run a server (the VNC server) and the clients which need to connect to it (with the possibility to do so simultaneously in many cases) running a client (the VNC client(s)).

In this tutorial, you will learn:

A list of the most prominent VNC utilities available for Linux
Which VNC server/client utility we like the best

How to Create SwapFiles in Ubuntu and Mint

2 April 2021 by Roel Van de Paar

A swapfile is a special file created on your computer’s disk, which will hold some of the memory contents. For example, when the main memory is starting to get full, the computer may write some of its memory to the swap space on the disk, which, albeit much slower than memory, will work as extra memory in the machine.

In this tutorial, you will learn:

How to identify if your system is swapping or not
The difference between a dedicated swap space partition and a swapfile
How to create a swapfile in Ubuntu and Linux Mint
How to configure the new swapfile into /etc/fstab
Example setting up a swapfile

Save Your Passwords at the Command Line With gopass (With Browser Plugins!)

2 April 2021 by Roel Van de Paar

Having a solid password manager is an absolute must these days, especially if you work in IT or regularly login to various social media. There are various options available under Linux, some more elegant than others. Out of all the options available, one that looks well crafted is gopass.

In this tutorial you will learn:

How to install gopass, the command line password manager
How to setup GPG and Git to work in conjunction with gopass
How to use gopass and what benefits and features it offers
How to enable the gopass browser extensions available for Firefox, Chrome and Chromium
How healthy the gopass and pass (on which it is based) communities and repositories are

What is dmesg in Linux, And How Do I Use It?

23 March 2021 by Roel Van de Paar

If you have been using Linux for some time, you will likely have come to appreciate how stable and configurable it is, especially if you have some idea of managing a Linux system well. One such tool in managing a system is checking the dmesg kernel log regularly, and especially when there is a problem with the system. The first place to go to is often the dmesg log.

In this tutorial, you will learn:

How to access the dmesg kernel log
How to use standard date and timestamps instead of the default (the number seconds since kernel was started)
What sort of information you can see in the kernel log

Hung Linux System? How to Escape to the Command Line and More

23 March 2021 by Roel Van de Paar

It is not much fun when your Desktop hangs. The fear of lost work, the inability to continue work, and more. But it need not always be like this. Knowing just a little extra – a few shortcut keyboard combinations and a few commands at the command line – will hopefully get you back up and running quickly. It does not always work, but it works often.

In this tutorial, you will learn:

How to do basic immediate troubleshooting steps on a hung system
How to execute a memory test using a Memtest86+ ISO image burned to disc
A number of keyboard shortcuts that will empower you to handle hung systems better
Information about what avenues to take to do further troubleshooting steps

How to Discover, From Inside a Bash Script, the Path the Script Is In

23 March 2021 by Roel Van de Paar

When you develop complex Bash scripts and start putting various scripts into a folder, where one script interacts with another by, for example, starting it, it quickly becomes necessary to ensure we know the path the script was started from, so we can start the other scripts with a fully qualified pathname. This is important because the first script may have been started from outside the script’s directory. We could have also done so by using a relative path, so even – somehow – reading the command that started the current script will not work.

In this tutorial, you will learn:

What the pwd command is, and what it does
How to discover from inside a Bash script what path that same script is in

Mint 20: Better Than Ubuntu and Microsoft Windows?

30 March 2021 by Roel Van de Paar

As a long term user of Microsoft Windows, Fedora, Ubuntu and Linux Mint, I have seen some of the more intricate tantrums a Windows or Linux operating system can throw. My first Mint 20 installation was in early April 2020, even before Mint 20 was released. I have had the unique opportunity to compare it with Microsoft Windows and Ubuntu 20 for day-to-day work and use, and have made some interesting discoveries. Read on to find out.

In this article you will learn:

How Linux Mint 20 stacks up to Ubuntu 20 from a practical perspective
Which desktop environments are available, and which one I recommend
How Linux Mint 20 compares with Microsoft Windows
How to install another file manager in Linux Mint 20

$Computer Math Basics: Binary, Decimal, Hexadecimal, Octal$

Computer Math Basics: Binary, Decimal, Hexadecimal, Octal

2 March 2021 by Roel Van de Paar

How we express a number depends on whether we are a computer or a human. If we are human, we are likely to express numbers using our familiar 10-base decimal system. If we are a computer, we are likely, at our core, to express numbers as 2-base or binary.

So what is up with all the many ways of expressing numbers, and why do they exists? This article will go into some detail and hopefully by the end you’ll be counting octal on your fingers. Which works fine by the way, as long as you use only 8 fingers, after all… octal is 8-base.

In this tutorial you will learn:

How to do simple counting in up non-decimal systems like binary, hexadecimal and octal.
What the terms 2-base, 10-base etc. stand for and how to understand them more easily.
The connection between these various methods of expressing numbers

Bash Change Directory (cd) Methods, Tips and Tricks

23 February 2021 by Roel Van de Paar

Changing directories in a terminal may have become a thing of the past for mainstream users. However, if you do any level of system administration work, testing work, Big Data Manipulation or similar, you will soon find yourself using the Change Directory (cd) command at the Bash or Linux terminal prompt more and more.

In this tutorial you will learn:

Simple terminal Change Directory (cd) command usage
Additional methods, tips and tricks for making a richer cd experience
Examples highlighting the use of the various cd commands

Bash Change Directory (cd) Methods, Tips and Tricks

Special Bash Variables with examples

16 February 2021 by Roel Van de Paar

Bash is a great coding language, which allows you to do complex things like Big Data Manipulation, or simply create sever or desktop management scripts.

The entry level skill required to use the Bash language is quite low, and one-liner scripts (an often used jargon, which indicates multiple commands executed at the command line, forming a mini-script), as well as regular scripts, can grow in complexity (and how well written they are) as the Bash developer learns more.

Learning to use special variables in Bash is one part of this learning curve. Whereas originally the special variables may look cryptic: $$, $?, $*, \$0, $1, etc., once you understand them and use them in your own scripts, things will soon become clearer and easier to remember.

In this tutorial you will learn:

How to use special variables in Bash
How to correctly quote variables, even special ones
Examples using special variables from the command line and scripts

Bash if Statements: if, elif, else, then, fi

15 December 2020 by Roel Van de Paar

If you are just starting to explore the Bash coding language, you will soon find yourself wanting to create conditional statements. Conditional statements, in other words, define ‘if a condition is true or false, then do this or that, and if the opposite is true, do something else’. This is the most basic function of any conditional statement.

This article will introduce you to the five basic if statement clauses. being if, elif, else, then and fi. The first simply opens a if statement, the then introduces the what commands to execute if the statement condition was true section and the else introduces the what commands to execute if the statement condition was false section. Finally, the fi closes the statement. We also have the special elif on which we will see more in a minute. Let’s start with an easy example.

In this tutorial you will learn:

How to implement an if statement at the Bash command line
How such if statements can also be used inside a Bash scripts
Examples showing you the if, elif, else, then and fi clauses in Bash

Process List Management and Automatic Process Termination

15 December 2020 by Roel Van de Paar

As sever optimal use/maximization continues to grow, it becomes more and more important to manage processes well. One aspect of this is automatic process termination. When a process has gone rogue, and is consuming too much resources, it can be terminated automatically.

This is especially suited to servers which have a lot of temporary or disposable processes. It is also well suited for testing servers which are running many test trials and where such test trials prove to be unstable or cause the software under testing to behave erratically (for example by using too much memory)

In this tutorial you will learn:

How to manage processes in an automated fashion
Which resources you may want to monitor, and why
Example code showing how automatic process termination can work for memory hogging issues