Learn Linux Shell Scripting Fundamentals of Bash 4.4

Create and maintain powerful Bash scripts for automation and administration.

Key Features

• Get up and running with Linux shell scripting using real-world examples
• Leverage command-line techniques and methodologies to automate common yet complex administration tasks
• A practical guide with exposure to scripting constructs and common scripting patterns

Book Description

Shell scripts allow us to program commands in chains and have the system execute them as a scripted event, just like batch files. This book will start with an overview of Linux and Bash shell scripting, and then quickly deep dive into helping you set up your local environment, before introducing you to tools that are used to write shell scripts. The next set of chapters will focus on helping you understand Linux under the hood and what Bash provides the user. Soon, you will have embarked on your journey along the command line. You will now begin writing actual scripts instead of commands, and will be introduced to practical applications for scripts. The final set of chapters will deep dive into the more advanced topics in shell scripting. These advanced topics will take you from simple scripts to reusable, valuable programs that exist in the real world. The final chapter will leave you with some handy tips and tricks and, as regards the most frequently used commands, a cheat sheet containing the most interesting flags and options will also be provided.

After completing this book, you should feel confident about starting your own shell scripting projects, no matter how simple or complex the task previously seemed. We aim to teach you how to script and what to consider, to complement the clear-cut patterns that you can use in your daily scripting challenges.

What you will learn

• Understand Linux and Bash basics as well as shell scripting fundamentals
• Learn to write simple shell scripts that interact with Linux operating system
• Build, maintain, and deploy scripts in a Linux environment
• Learn best practices for writing shell scripts
• Avoid common pitfalls associated with Bash scripting
• Gain experience and the right toolset to write your own complex shell scripts

Who this book is for

This book targets new and existing Linux system administrators, Windows system administrators or developers who are interested in automating administrative tasks. No prior shell scripting experience is needed but in case you do this book will make a pro quickly. Readers should have a basic understanding of the command line.

Table of Contents

1. Introduction
2. Setting up your local environment
3. Choosing the right tools
4. The Linux filesystem
5. Understanding the Linux permissions scheme
6. File manipulation
7. Hello World!
8. Variables and user input
9. Error checking and handling
10. Regular expressions
11. Conditional testing and scripting loops
12. Using pipes and redirection in scripts
13. Functions
14. Scheduling and logging
15. Parsing Bash script arguments with getopts
16. Bash parameter substitution and expansion
17. Tips & tricks (with cheat sheet)