Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
The Ultimate Linux Shell Scripting Guide

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

Arrow left icon
Product type Paperback
Published in Oct 2024
Publisher Packt
ISBN-13 9781835463574
Length 696 pages
Edition 1st Edition
Languages
Tools
Arrow right icon
Author (1):
Arrow left icon
Donald A. Tevault Donald A. Tevault
Author Profile Icon Donald A. Tevault
Donald A. Tevault
Arrow right icon
View More author details
Toc

Table of Contents (26) Chapters Close

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

Answers

  1. In the if statement, you need to insert a blank space between the [ and the $a.
  2. You need to place a done statement after the echo $i statement.
  3. There are a couple of problems with this script. First, the regular expression is set up wrong, which causes you to get either no or incorrect output from this script. Instead of

[a-z]*.sh, it should be [a-z].sh. (The * actually isn’t needed for this.)

You can review the concept of regular expressions in Chapter 9—Filtering Text with grep, sed, and Regular Expressions.

There’s also the fact this regular expression isn’t doing much for us. Unless you have scripts with filenames that consist of nothing but either digits or upper-case characters, this grep command is going to show you all of the scripts in your directory. So, you could probably just omit the grep command altogether, and go with a simple ls *.sh command.

Finally, in the echo statement, you...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime