You're reading from The Ultimate Linux Shell Scripting Guide Automate, Optimize, and Empower tasks with Linux Shell Scripting

Product type Paperback

Published in Oct 2024

Publisher Packt

ISBN-13 9781835463574

Length 696 pages

Edition 1st Edition

Languages

Bash

Tools

Linux

Concepts

Cybersecurity

Author (1):

Donald A. Tevault

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Table of Contents (26) Chapters

Preface

1. Getting Started with the Shell FREE CHAPTER

2. Interpreting Commands

3. Understanding Variables and Pipelines

4. Understanding Input/Output Redirection

5. Customizing the Environment

6. Text-Stream Filters – Part 1

7. Text Stream Filters – Part 2

8. Basic Shell Script Construction

9. Filtering Text with grep, sed, and Regular Expressions

10. Understanding Functions

11. Performing Mathematical Operations

12. Automating Scripts with here Documents and expect

13. Scripting with ImageMagick

14. Using awk – Part 1

15. Using awk – Part 2

16. Creating User Interfaces with yad, dialog, and xdialog

17. Using Shell Script Options with getops

18. Shell Scripting for Security Professionals

19. Shell Script Portability

20. Shell Script Security

21. Debugging Shell Scripts

22. Introduction to Z Shell Scripting

23. Using PowerShell on Linux

24. Other Books You May Enjoy

25. Index

Looking at Real-world Examples

Now that I’ve demonstrated the theory of using getopts, it’s time to get down to business with a couple of real-world examples. Enjoy!

The Modified Coingecko Script

In Chapter 10, Understanding Functions, I showed you a pair of cool scripts that I created for my own use. To review, these scripts use the Coingecko API to automatically fetch information about cryptocurrencies.

The coingecko.sh script uses an if. .elif. .else construct to allow me to choose the function that I want to perform. In the coingecko-case.sh script, I use a case. .esac construct to achieve the same thing. Now, I present the third incarnation of the script, which uses getopts.

The coingecko-getopts.sh script is too large to reproduce here, so you’ll need to grab it from GitHub. I do need to point out a few things about it, so I’ll just show the relevant snippets here.

At the beginning of the script, I added the gecko_usage() function...