Ilya Shpigor [Илья Шпигорь] - Bash programming from scratch

Learning to program is not easy. It is even more challenging if you start from scratch and learn it on your own without mentors. This task is feasible, but its result depends on you.

You are going to study a new and complex subject. It will require strong motivation. Therefore, consider your goals before you continue reading this book. What do you expect from your new skills? What tasks will your programs solve? Answers to these questions help you to choose an effective way to study.

If you firmly intend to become a professional programmer in the shortest possible time, you need a mentor. Enroll yourself in a full-time or online course. It accelerates your progress significantly. You will get a chance to communicate directly with the mentor, ask him questions, and clarify unclear topics.

You can learn programming without a mentor if you do it for curiosity. Do you want to get a new hobby or learn a new fancy thing? In this case, self-study with the book is the right way. It will bring you practical benefits for relatively small efforts. After all, basic programming skills are helpful for anyone who works with the computer. Perhaps this book would be a starting point for you. It will help you to choose a direction for your further development.

Today there are plenty of books available in online shops and libraries. A reader with any technical level can find appropriate material for him. You can ask about the reason for writing this particular book.

Programming is a practical domain. Yes, it has a lot of theory. But mathematics has a lot of theory too. However, just knowing formulas does not make you a mathematician. In the same way, knowing the fundamental principles of software development does not make you a programmer.

You have to write a lot of code on your own to become a programmer. At first, this code wont work. Then, it will contain errors. Gradually, you will learn how to anticipate and fix the mistakes in advance. Knowledge of a particular language does not indicate your progress. But an evaluation of your old code does it. When you read your code several months later and notice its disadvantages, it confirms your progress.

So what is wrong with existing books? Many of them focus on a specific language or technology. They consider the chosen theme in detail. In this case, the author does not pay enough attention to practical exercises. A beginner programmer does not need such a volume of specialized knowledge. It brings him the wrong idea of how to learn to program. It is rarely that somebody reads such books for specific technologies from cover to cover. More often, they are used as a reference manual when the specific practical question arises.

Books of another type teach you some programming language by examples. When you study such a book, your progress goes faster. But there is one problem here. Many readers do not find the motivation to work with examples. The author offers you to read and understand a lot of code. Often, this code demonstrates a specific principle and does not have a practical use case. Therefore, such examples are not attractive to readers.

Modern general-purpose languages are complex. It means that you should know a lot about the language before dealing with real-life tasks. Here we meet a vicious circle. Examples are not interesting because they are useless. But useful real-life programs are too hard to understand for a beginner.

This book follows another approach. It starts with a general theory about a computer. Here we pay attention to the reasons for the technical solutions of the past. These solutions have defined the basic features of a modern computer. Following the reasons helps you to learn the material quickly.

The general theory about a computer helps you when you start programming in a particular language. You will certainly meet problems. For example, your program runs too slow or ends up with an error all the time. Knowing the internals of a computer helps you to understand the reasons for such behavior.

The next part of this book introduces you to the Bash programming language. Contrary to popular belief, it is a complex domain-specific language. However, there are some practical tasks that it solves easily and laconically. We will use them as examples. This way, we will learn the basic concepts of programming.

Our first step is replacing the graphical user interface with the shell. It will teach you basic operations on files and directories using Bash commands. When we get this basic syntax, we apply it and write our first Bash programs.

Please do not consider learning Bash as a necessary but useless exercise. Every professional programmer faces tasks of automating some processes and executing commands on a Unix-like system. Bash knowledge is irreplaceable in both cases.

If you are not able to complete some example or exercise, do not be upset. It means that the book does not disclose material sufficiently. Please to me about this. We will consider it out together.

There is a glossary at the end of the book. There you can clarify an unknown term that you met while reading the book.