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

Obtaining Input from Commands

Let’s start with something simple, by obtaining some basic process information. On the Fedora Server virtual machine that’s running Apache, search for all ps aux output lines that contain the httpd pattern, like so:

donnie@fedora:~$ ps aux | awk '/httpd/ {print $0}'
root        1072  0.0  0.2  19108 10796 ?        Ss   14:36   0:01 /usr/sbin/httpd -DFOREGROUND
apache      1111  0.0  0.1  19204  6788 ?        S    14:36   0:00 /usr/sbin/httpd -DFOREGROUND
apache      1112  0.0  0.2 2158280 8448 ?        Sl   14:36   0:02 /usr/sbin/httpd -DFOREGROUND
apache      1113  0.0  0.2 2420488 8592 ?        Sl   14:36   0:03 /usr/sbin/httpd -DFOREGROUND
apache      1114  0.0  0.2 2158280 8448 ?        Sl   14:36   0:02 /usr/sbin/httpd -DFOREGROUND
donnie      1908  0.0  0.0   9196  3768 pts/0    S+   17:13   0:00 awk /httpd/ {print $0}
donnie@fedora:~$

Next, let’s say that we want to see all processes that are owned by the...