Book Image

Linux Essentials - Second Edition

By : Christine Bresnahan, Richard Blum
Book Image

Linux Essentials - Second Edition

By: Christine Bresnahan, Richard Blum

Overview of this book

Linux Essentials, Second Edition provides a solid foundation of knowledge for anyone considering a career in information technology, for anyone new to the Linux operating system, and for anyone who is preparing to sit for the Linux Essentials Exam. Through this engaging resource, you can access key information in a learning-by-doing style. Hands-on tutorials and end-of-chapter exercises and review questions lead you in both learning and applying new information—information that will help you achieve your goals! With the experience provided in this compelling reference, you can sit down for the Linux Essentials Exam with confidence. An open-source operating system, Linux is a UNIX-based platform that is freely updated by developers. The nature of its development means that Linux is a low-cost and secure alternative to other operating systems, and is used in many different IT environments. Passing the Linux Essentials Exam prepares you to apply your knowledge regarding this operating system within the workforce.
Table of Contents (19 chapters)
17
EULA

CHAPTER 11
Creating Scripts

A script is a program written in an interpreted language, typically associated with a shell or a compiled program. In Linux, many scripts are shell scripts, which are associated with Bash or another shell. (If you’re familiar with batch files in Windows, scripts serve a similar purpose.) You can write shell scripts to help automate tedious, repetitive tasks or to perform new and complex tasks. Scripts perform many of Linux’s startup functions, so mastering scripting will help you manage the startup process.

This chapter covers Bash shell scripts, beginning with the task of creating a new script file. We then describe several important scripting features that help you to perform progressively more complex scripting tasks.

  • Beginning a shell script
  • Using commands
  • Using arguments
  • Using variables
  • Using conditional expressions
  • Using loops
  • Using functions
  • Setting the script’s exit value