Pro Bash

Learn how to effectively utilize the Bash shell in your programming. This refreshed and expanded third edition has been updated to Bash 5.2, and many scripts have been rewritten to make them more idiomatically Bash, taking better advantage of features specific to Bash. It is easy to read, understand, and will teach you how to get to grips with Bash programming without drowning you in pages and pages of syntax.
Using this book you will be able to use the shell efficiently, make scripts run faster using expansion and external commands, and understand how to overcome many common mistakes that cause scripts to fail. This book is perfect for all beginning Linux and Unix system administrators who want to be in full control of their systems, and really get to grips with Bash programming.

The Bash shell is a complete programming language, not merely a glue to combine external Linux commands. By taking full advantage of Shell internals, Shell programs can perform as snappily as utilities written in C or other compiled languages. And you will see how, without assuming UNIX lore, you can write professional Bash  programs through standard programming techniques.

You will:
Use the Bash shell to write utilities and accomplish most programming tasksReplace many external commands with shell parameter expansion making scripts very fastAvoid many common mistakes that cause scripts to failSee how Bash’s read line and history libraries can save typing when getting user inputBuild shell scripts that get information from the Web