It is assumed that some readers may have limited or no knowledge about Linux operating systems. It is also assumed that some readers are Linux users but may need a bit of a refresher on interfacing with a Linux environment.

The key to reinforcing each chapter to memory is by grabbing copies of various Linux distributions; namely CentOS, Fedora, and Ubuntu. Then install the various Operating Systems in a virtual environment such as VMware or VirtualBox. Next, follow along each chapters (the chapters are independent of each other so you can choose any given chapter to study/practice) by practicing inside the various Linux distributions in order to better grasp each chapter. After practicing the various chapters, you will become more productive within a Linux environment; this will empower you to be better equipped in mixed environments where there are both Windows and Linux Operating Systems.

You can follow the along the tutorials presented in Chapter 5, Installing a Linux Distribution of this book for getting started with installation.

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it here: https://www.packtpub.com/sites/default/files/downloads/9781789344493_ColorImages.pdf.

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "To see the runlevel at the shell in real time, we can use the runlevel command."

A block of code is set as follows:

while <condition>
do
          <command1>
          <command2 

Any command-line input or output is written as follows:

$[philip@localhost Desktop]$ who -r
run-level 5 2018-06-20 08:20 last=S
[philip@localhost Desktop]$ 

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."