Preface

Shell scripts are an essential part of any modern operating system, such as UNIX, Linux, Windows, and similar. The scripting language or its syntax may vary from OS to OS; but the fundamental principles remain the same. I first encountered Linux Shell scripts during the development of embedded Linux product development. Shell scripts were initializing the complete product from the basic booting procedure until users logged in and a complete operating system was initialized. Another situation was in the automation of regular activities, such as the build and release management of source codes of very complex products, where more than 10,000 files were a part of a single project. Similarly, another very common requirement comes while using the make utility, which is used to compile and build complex product source codes.

Initially, I had learned scripts to solve practical problems and customize already existing products. This book is the summary of what I have learned over the years in Linux Shell scripting during project development work, consultancy, and corporate trainings and their Q&A sessions.

In this book, you will learn about the very basics of Shell scripting to complex, customized automation. By the end of this book, you will be able to confidently use your own Shell scripts for the real-world problems out there. The idea is to be as practical as possible and give you the look and feel of what real-world scripting looks like.

This book covers bash, the GNU Bourne-Again Shell scripting. You can use the knowledge gained by reading this book for any shell of any of the UNIX flavors or distributions. You will need to take care of a few syntax changes if you are working in other shells, such as Korn, and similar. You should be able to read this book cover to cover, or you can just pick it up and read anything that you might find interesting. But perhaps most importantly, if you have a question about how to solve a particular problem or you need a hint, you will find it easy to find the right solution or something close enough to save your time and energy.