Book Image

Linux for System Administrators

By : Viorel Rudareanu, Daniil Baturin
Book Image

Linux for System Administrators

By: Viorel Rudareanu, Daniil Baturin

Overview of this book

Linux system administration is an essential aspect of maintaining and managing Linux servers within an organization. The role of a Linux system administrator is pivotal in ensuring the smooth functioning and security of these servers, making it a critical job function for any company that relies on Linux infrastructure. This book is a comprehensive guide designed to help you build a solid foundation in Linux system administration. It takes you from the fundamentals of Linux to more advanced topics, encompassing key areas such as Linux system installation, managing user accounts and filesystems, networking fundamentals, and Linux security techniques. Additionally, the book delves into the automation of applications and infrastructure using Chef, enabling you to streamline and optimize your operations. For both newcomers getting started with Linux and professionals looking to enhance their skills, this book is an invaluable hands-on guide with a structured approach and concise explanations that make it an effective resource for quickly acquiring and reinforcing Linux system administration skills. With the help of this Linux book, you’ll be able to navigate the world of Linux administration confidently to meet the demands of your role.
Table of Contents (21 chapters)
Part 1: Linux Basics
Part 2: Configuring and Modifying Linux Systems
Part 3: Linux as a Part of a Larger System

Process termination and exit codes

All processes have to eventually terminate, and there are many situations when process execution cannot continue, either due to errors in its own program logic or problems with the environment (such as missing files, for example). The user may also need to terminate processes by hand, either to make changes to the system, or to prevent a misbehaving process from taking up resources or interfering with the system’s functioning.

In this section, we will learn how to examine the exit code of a terminated process to guess the possible reasons for its termination, and how to communicate with processes and force their termination.

Exit codes

Most processes are short-lived – they do their job and terminate by themselves. Every process terminates with an exit code – a numeric value that indicates whether it exited normally or terminated due to an error. By convention, a zero exit code means success, and any non-zero exit code...