Book Image

Learn Linux Shell Scripting – Fundamentals of Bash 4.4

By : Sebastiaan Tammer
Book Image

Learn Linux Shell Scripting – Fundamentals of Bash 4.4

By: Sebastiaan Tammer

Overview of this book

Shell scripts allow us to program commands in chains and have the system execute them as a scripted event, just like batch files. This book will start with an overview of Linux and Bash shell scripting, and then quickly deep dive into helping you set up your local environment, before introducing you to tools that are used to write shell scripts. The next set of chapters will focus on helping you understand Linux under the hood and what Bash provides the user. Soon, you will have embarked on your journey along the command line. You will now begin writing actual scripts instead of commands, and will be introduced to practical applications for scripts. The final set of chapters will deep dive into the more advanced topics in shell scripting. These advanced topics will take you from simple scripts to reusable, valuable programs that exist in the real world. The final chapter will leave you with some handy tips and tricks and, as regards the most frequently used commands, a cheat sheet containing the most interesting flags and options will also be provided. After completing this book, you should feel confident about starting your own shell scripting projects, no matter how simple or complex the task previously seemed. We aim to teach you how to script and what to consider, to complement the clear-cut patterns that you can use in your daily scripting challenges.
Table of Contents (24 chapters)
Title Page
About Packt
Contributors
Preface
Free Chapter
1
Introduction
Index

Working with multiple users


As we've stated before, Linux is inherently a multi-user system, especially in the context of a Linux server, where these systems are often administered not by a single user, but often a (large) team. Each user on a server has it own set of permissions. Imagine, for example, a server where three departments need to be development, operations, and security. Development and operations both have their own stuff there, but also need to share some other things. The security department needs to be able to view everything to ensure proper compliance and adherence to security guidelines. How could we arrange such a structure? Let's make it happen!

First, we need to create some users. For each department, we will create a single user, but since we're going to ensure permissions on the group level, this will work just as well for 5, 10, or 100 users in each department. We can create users with the useradd command. In its basic form, we can just use useradd <username&gt...