Book Image

Mastering Linux Shell Scripting - Second Edition

By : Mokhtar Ebrahim, Andrew Mallett
5 (1)
Book Image

Mastering Linux Shell Scripting - Second Edition

5 (1)
By: Mokhtar Ebrahim, Andrew Mallett

Overview of this book

In this book, you’ll discover everything you need to know to master shell scripting and make informed choices about the elements you employ. Grab your favorite editor and start writing your best Bash scripts step by step. 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. You will also learn to write complex shell scripts. This book will also deep dive into file system administration, directories, and system administration like networking, process management, user authentications, and package installation and regular expressions. Towards the end of the book, you will learn how to use Python as a BASH Scripting alternative. By the end of this book, you will know shell scripts at the snap of your fingers and will be able to automate and communicate with your system with keyboard expressions.
Table of Contents (17 chapters)

Summary

Within this chapter, I really hope that we have introduced many new and interesting choices to you. This was an area with a wide range where we began by recapping the use of test and discovered that the [ is a command not a syntax construct. The main effect that it is a command is on white space and we looked at the need to quote variables.

Even though we may commonly call variables variables, we have also seen that their correct name, especially in documentation, is parameters. Reading a variable is a parameter expansion. Understanding parameter expansion can help us understand the use of the keyword [[. The double square brackets are not commands and do not expand the parameters. This means that we do not need to quote variables even if they do contain white space. Moreover, we can use advanced tests with double square brackets, such as pattern matching or regular expressions...