You're reading from Mastering Bash

Product type Book

Published in Jun 2017

Publisher Packt

ISBN-13 9781784396879

Pages 502 pages

Edition 1st Edition

Languages

Bash

Concepts

Shell Scripting

Author (1):

Giorgio Zarrelli

Table of Contents (15) Chapters

Preface

1. Let's Start Programming

2. Operators

3. Testing

4. Quoting and Escaping

5. Menus, Arrays, and Functions

6. Iterations

7. Plug into the Real World

8. We Want to Chat

9. Subshells, Signals, and Job Controls

10. Lets Make a Process Chat

11. Living as a Daemon

12. Remote Connections over SSH

13. Its Time for a Timer

14. Time for Safety

Returning code and thresholds

Before coding a plugin, we must face some concepts that will be the stepping stone of our Nagios code base, one of these being the return codes of the plugin itself. As we already discussed, once the plugin collects the data about how the service is going, it evaluates these data and determines if the situation falls under one of the following status:

Return code	Status	Description
`0`	OK	The plugin checked the service and the results that are inside the acceptable range.
`1`	WARNING	The plugin checked the service and the results that are above a WARNING threshold. We must keep an eye on the service.
`2`	CRITICAL	The plugin checked the service and the results that are above a CRITICAL threshold or the service not responding. We must react now.
`3`	UNKNOWN	Either we passed the wrong arguments to the plugin or there is...

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Authors (1)

Giorgio Zarrelli

Giorgio Zarrelli is a passionate GNU/Linux system administrator and Debian user, but has worked over the years with Windows, Mac, and OpenBSD, writing scripts, programming, installing and configuring services--whatever is required from an IT guy. He started tinkering seriously with servers back in his university days, when he took part in the Computational Philosophy Laboratory and was introduced to the Prolog language. As a young guy, he had fun being paid for playing games and write about them in video game magazines. Then he grew up and worked as an IT journalist and Nagios architect, and recently moved over to the threat intelligence field, where a lot of interesting stuff is happening nowadays. Over the years, he has worked for start-ups and well-established companies, among them In3 incubator and Onebip as a database and systems administrator, IBM as QRadar support, and Anomali as CSO, trying to find the best ways to help companies make the best out of IT. Giorgio has written several books in Italian on different topics related to IT, from Windows security to Linux system administration, covering MySQL DB administration and Bash scripting.

See other products by Giorgio Zarrelli