Book Image

Mastering Bash

By : Giorgio Zarrelli
Book Image

Mastering Bash

By: Giorgio Zarrelli

Overview of this book

System administration is an everyday effort that involves a lot of tedious tasks, and devious pits. Knowing your environment is the key to unleashing the most powerful solution that will make your life easy as an administrator, and show you the path to new heights. Bash is your Swiss army knife to set up your working or home environment as you want, when you want. This book will enable you to customize your system step by step, making your own real, virtual, home out of it. The journey will take you swiftly through the basis of the shell programming in Bash to more interesting and challenging tasks. You will be introduced to one of the most famous open source monitoring systems—Nagios, and write complex programs with it in any languages. You’ll see how to perform checks on your sites and applications. Moving on, you’ll discover how to write your own daemons so you can create your services and take advantage of inter-process communication to let your scripts talk to each other. So, despite these being everyday tasks, you’ll have a lot of fun on the way. By the end of the book, you will have gained advanced knowledge of Bash that will help you automate routine tasks and manage your systems.
Table of Contents (15 chapters)

Menus, Arrays, and Functions

Writing a script often means having to deal with user interaction. You want to know what the user expects from your script, and you want to let the user know what options they have to decide from. So, we give the user some choices, they give us their answers, we evaluate them against some preset values, and decide what to do next. This implies a method to expose some data to the user, gather their answer, cycle between options, and react accordingly. There are different ways to do this, and we will see how to accomplish the task using some standard constructs. At the end of this chapter, we will be able to offer, gather, store, and process data efficiently.