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Learn Linux Shell Scripting – Fundamentals of Bash 4.4

You're reading from   Learn Linux Shell Scripting – Fundamentals of Bash 4.4 A comprehensive guide to automating administrative tasks with the Bash shell

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Product type Paperback
Published in Dec 2018
Publisher Packt
ISBN-13 9781788995597
Length 452 pages
Edition 1st Edition
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Author (1):
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Sebastiaan Tammer Sebastiaan Tammer
Author Profile Icon Sebastiaan Tammer
Sebastiaan Tammer
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Table of Contents (20) Chapters Close

Preface 1. Introduction FREE CHAPTER 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 and Tricks with Cheat Sheet 18. Assessments 19. Other Books You May Enjoy

Functions explained

In this chapter, we're going to look at functions, and how these can enhance your scripts. The theory of functions is not too complicated: a function is a set of commands grouped together that can be called (executed) multiple times without having to write the whole set of commands again. As always, a good example is worth a thousand words, so let's dive right in with one of our favorite examples: printing Hello world!.

Hello world!

We now know it's relatively easy to get the words Hello world! to appear on our terminal. A simple echo "Hello world!" does just the trick. However, if we wanted to do this multiple times, how would we go about it? You could suggest using any kind of...

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