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)

Testing

We have stressed so far the importance of giving a structure to our scripts, to make them flexible, and to have them react to some conditions and situations so that they will help us automate some routine tasks making decisions and performing actions on our behalf. What we saw in the previous chapters enables us to assign variables, change their values in different ways, and also to preserve them; but from the examples shown, it is clear that we need some more and this is what this new chapter is all about. We will see how to test, make comparisons, and get to react accordingly to the results, and we will give our first structure to a script having to make a decision if something happens.