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

What is Perl?

Perl is a scripting language that was developed in the 1980's by Larry Wall to extend the functionality of sed and awk. It is an acronym for Practical Extraction and Reporting Language but has grown far bigger than its original purpose and today it is available on Unix, Linux, OS X, and Windows operating systems.

Although, it is a scripting language, it is not shell scripting; as such there is no Perl shell. This means that the code has to be executed via Perl scripts and not directly from the command line. The exception to this is the -e option to the perl command that can allow you to execute a perl statement. For example, we can use the following command line to print the ubiquitous Hello World:

$ perl -e ' print("Hello World\n");'

You will find that Perl is installed by default on most Linux and Unix systems as many programs will make use of Perl in their code. To check the version of Perl that you have installed on your system you can use the perl command, as follows:

$ perl...