Book Image

Fundamentals of Linux

By : Oliver Pelz
Book Image

Fundamentals of Linux

By: Oliver Pelz

Overview of this book

Linux is a Unix-like operating system assembled under the model of free and open source software development and distribution. Fundamentals of Linux will help you learn all the essentials of the Linux command line required to get you started. The book will start by teaching you how to work with virtualization software and install CentOS 7 Linux as a VM. Then, you will get to grips with the workings of various command line operations, such as cursor movement, commands, options, and arguments. As you make your way through the chapters, the book will not only focus on the most essential Linux commands but also give an introduction to Bash shell scripting. Finally, you will explore advanced topics, such as networking and troubleshooting your system, and you will get familiar with the advanced file permissions: ACL, setuid, and setgid. Fundamentals of Linux includes real-world tasks, use cases, and problems that, as a system administrator, you might encounter in your day-to-day activities.
Table of Contents (7 chapters)

Working with Bash shell variables

In this section, we will introduce you to Linux Bash shell variables. Bash shell variables are a great way to give symbolic names to any dynamic values, so we can reference values by a name. This helps to create very flexible and convenient systems where you often only have to change a single value, and all processes on your computer accessing this value can change their behavior automatically. Using shell variables provides a simple way to share configuration settings between multiple applications and processes in Linux, as we will see in the next section. To define a new environment variable, use the following syntax MY_VALUE=1, name of the variable equals, then the value. All Bash shell variables must not contain spaces or special characters, and, by convention, often shell variables are all uppercase. To access the stored value of the shell...