Book Image

Mastering Linux Shell Scripting

By : Andrew Mallett
Book Image

Mastering Linux Shell Scripting

By: Andrew Mallett

Overview of this book

Shell scripting is a quick method to prototype a complex application or a problem by automating tasks when working on Linux-based systems. Using both simple one-line commands and command sequences complex problems can be solved with ease, from text processing to backing up sysadmin tools. In this book, you’ll discover everything you need to know to master shell scripting and make informed choices about the elements you employ. Get to grips with the fundamentals of creating and running a script in normal mode, and in debug mode. Learn about various conditional statements' code snippets, and realize the power of repetition and loops in your shell script. Implement functions and edit files using the Stream Editor, script in Perl, program in Python – as well as complete coverage of other scripting languages to ensure you can choose the best tool for your project.
Table of Contents (21 chapters)
Mastering Linux Shell Scripting
About the Author
About the Reviewer

Chapter 10. Awk Fundamentals

The stream editor is not alone in its family and has a big brother awk. In this chapter, we will run through the basics or fundamentals of awk and see the power of the awk programming language. We will learn why we need and love awk and how we can make use of some of the basic features before we start putting awk to practical use in the next two chapters. As we work our way through this, we will cover the following topics:

  • Filtering content from files

  • Formatting output

  • Displaying non-system users from /etc/passwd

  • Using awk control files