Book Image

The Software Developer's Guide to Linux

By : David Cohen, Christian Sturm
5 (2)
Book Image

The Software Developer's Guide to Linux

5 (2)
By: David Cohen, Christian Sturm

Overview of this book

Developers are always looking to raise their game to the next level, yet most are completely lost when it comes to the Linux command line. This book is the bridge that will take you to the next level in your software development career. Most of the skills in the book can be immediately put to work to make you a more efficient developer. It’s written specifically for software engineers, not Linux system administrators, so each chapter will equip you with just enough theory to understand what you’re doing before diving into practical commands that you can use in your day-to-day work as a software developer. As you work through the book, you’ll quickly absorb the basics of how Linux works while you get comfortable moving around the command line. Once you’ve got the core skills, you’ll see how to apply them in different contexts that you’ll come across as a software developer: building and working with Docker images, automating boring build tasks with shell scripts, and troubleshooting issues in production environments. By the end of the book, you’ll be able to use Linux and the command line comfortably and apply your newfound skills in your day-to-day work to save time, troubleshoot issues, and be the command-line wizard that your team turns to.
Table of Contents (20 chapters)
18
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19
Index

Root versus everybody else

The world can be a harsh place, and sometimes it’s dangerous to run a command. For example, fdisk can wipe the partitions of a disk or otherwise modify hardware. iptables can open a network port and let an attacker exploit a vulnerability. Even using an innocuous echo command to send a value to the wrong place on a filesystem can change the operating system’s configuration in subtle and terrible ways.

To guard against this, the Unix-like environment that your command-line interface is running in has some built-in guardrails. There is a “superuser” called root in every Unix system. As a result, the basic security model is as follows:

  • First, there is root. This user is the equivalent of the system administrator on other systems and is the user with the highest number of permissions. root can do almost anything.
  • Then, there’s everybody else. Non-root users have limited permissions – they can...