Book Image

Mastering Ubuntu Server - Fourth Edition

By : Jay LaCroix
4.8 (5)
Book Image

Mastering Ubuntu Server - Fourth Edition

4.8 (5)
By: Jay LaCroix

Overview of this book

Ubuntu Server is taking the server world by storm - and for a good reason! The server-focused spin of Ubuntu is a stable, flexible, and powerful enterprise-class distribution of Linux with a focus on running servers both small and large. Mastering Ubuntu Server is a book that will teach you everything you need to know in order to manage real Ubuntu-based servers in actual production deployments. This book will take you from initial installation to deploying production-ready solutions to empower your small office network, or even a full data center. You'll see examples of running an Ubuntu Server in the cloud, be walked through set up popular applications (such as Nextcloud), host your own websites, and deploy network resources such as DHCP, DNS, and others. You’ll also see how to containerize applications via LXD to maximize efficiency and learn how to build Kubernetes clusters. This new fourth edition updates the popular book to cover Ubuntu 22.04 LTS, which takes advantage of the latest in Linux-based technologies. By the end of this Ubuntu book, you will have gained all the knowledge you need in order to work on real-life Ubuntu Server deployments and become an expert Ubuntu Server administrator who is well versed in its feature set.
Table of Contents (26 chapters)
24
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25
Index

Understanding variables

Bash is more than just a shell. You could argue that it is very similar to a complete programming language, and you wouldn’t be wrong. Bash has a built-in scripting engine (we will get into scripting later) and there are many debates as to what distinguishes a scripting language from a programming language, and that line becomes more and more blurred as new languages come out.

As with any scripting language, Bash supports variables. The concept of variables is very simple in Bash, but I figured I’d give it its own (relatively short) section to make sure you understand the basics. You can set a variable with a command such as the following:

myvar='Hello world!'

When Bash encounters an equal sign after a string, it assumes you’re creating a variable. Here, we’re creating a variable named myvar and setting it equal to Hello world! Whenever we refer to a variable, though, we need to specifically clarify to Bash...