Learning the Unix OS

LearningTheUnixOS_5th_Edition.jpgLearning the Unix OS - 5th Edition
Jerry Peek, Grace Todino & John Strang ( O'Reilly, 2002 )

This book is now over 20 years old, yet it has aged gracefully.
Roughly 90% of the information inside is still relevant today and the other 10% can be treated as a history lesson. 
The reason can be found in the book's preface.

This book teaches basic system utility commands to get you started with Unix... We cover a commands most useful features...

And it more than lives up to its purpose. While Linux & Unix have changed a lot over the years the command line itself hasn't changed radically. The reason why the commands shown are interchangeable is that many of the core commands are identical in terms of syntax and functionality between Unix & Linux. There are of course some differences, but they are not enough to be a problem at our current level. We won't learn about Modern Filesystems or Containers, but we will learn enough to get even more confident with working through Linux.

Book Overview

Our next step in the systems fundamentals course will be Learning The Unix OS by O'Reilly. You may treat this book as a Practical Guide to Unix. This book is 157 pages long and will take you 7 days to finish if you dedicate between 2-3 hours every day to work through it.

When you look at the title you will notice the word Unix, but don't let the word Unix discourage you. Much of what we will be going over will be regarding the Command Line Interface. Which for our purposes is practically interchangeable with Linux. Don't misunderstand, they are two different operating systems, with the key difference being that Linux is Open-Source while Unix is Proprietary

The main goal of this book is to serve as a Practical Starter Guide, covering the main essentials of the CLI and Unix OS. That is why this book is still remains relevant even today. While we did go through an introductory course already, that being the Linux Upskill Challenge, there are some nuances that that this book goes through that will be very helpful to us.
We'll explore the various types of commands, Windows Systems, basic File Management, I/O-Redirection and even some interesting pieces of Linux history. When I finished going through this book, I felt confident that I could start working on this roadmap and bring something interesting to the table. Although we still have a long way to go before we can call ourselves true adepts, but steadily, we are making progress.

Personal Note

( The following has been added to the overview page. But I am keeping this here as this was when I thought of the idea. )
Throughout this journey I will do my best to be as objective as I can. However, I am still in the middle of my learning and I am only human. While technology itself is neutral, the way we use it, how we think about it, what we think is best moving forward and so on, are things that are human viewpoints. There are of course times when things are simply 0 or 1, but as you go through your own journey you will find that you will have to come up with your own definitions and reasons for doing things backed by personal preference or well researched analysis or simply that's the way things are done. 
So, to carry on with that spirit I will place the sparkling star icon✨ whenever certain notes or topics are things I am speaking my own mind on. I encourage you to come up with your own analysis or thoughts on those topics.

Goals of this Book
Course Notes

I quite enjoyed making the notes for this book since it led me to making several web searches on various different topics about Linux both old and new. 

Required Reading

Our required reading for this section will be a mix of reviewing old commands with learning new ones. We begin by covering some particularly useful List and System/Network monitoring commands. For those I recommend using the man page in order to get more comfortable with using the man command. After that we'll cover some articles on the Digital Ocean and RedHat community blogs that cover some more useful commands.

✨Finally we end with a more philosophical article, technical ability is important but I encourage you to consider the abstract side as well. Primarily questions like: "Why is Unix & Linux designed this way?" "What the point of FOSS?" and musings of that nature. 

( Self-Guided ) - Look into the following commands and go through them by using the man command. Read the Name, Synopsis, Description and go over some of the Options, then try the commands out. For system memory commands I recommend paying attention to the -h flag which shows displays the output in a human readable format. After you read the command's man page if it's use-case or meaning is unknown to you, do a web-search for more information.

( Article ) Digital Ocean Community: Top 50+ Linux Commands by e...f - By this point we have gone over most of the commands listed in the Digital Ocean article. I recommend reviewing any commands you're not confident in and pick up any that you may not know.

( Article ) RedHat - Enable Sysadmin: Linux Commands: du... by Tyler Carrigan - The du command is an excellent tool that will give you insight into how your storage is being used. This short article will go over the most used flags and how to make the most of them. 

( Article ) RedHat - Enable Sysadmin: How to Manage Linux Permissions... by Damon Garn - Managing user permissions is an essential task for any sysadmin. User access control is an essential security feature meant to protect data by giving only certain users access to data and resources based on certain contexts. If you still feel unconfident about managing permissions focus on this post and make sure to understand absolute/octal mode.

( Article ) Linux-Databook: The Unix and Linux Philosophy by dboth - Every Operating System has it's own philosophy. To steal the quote listed in the post. 

An operating system, by its nature, embodies the philosophy of its creators…"  - Mike Gancarz

Essentially any OS from Linux to Windows to macOS has their own way of doing things. It's Linux's philosophy that makes it so powerful in a capable users hand. As always I recommend you take away your own conclusions from this article. You may agree with much of it now and maybe come to disagree with much of it later and vice versa, even I don't agree with every tenet.

( Article ) itsfoss: 21 Terminal Shortcuts by Sagar Sharma - Lastly, we cover Terminal Shortcuts. They might not seem like such a big deal but getting the hang of a couple shortcuts can make a big difference for your efficiency and speed leading to substantial quality of life improvements.

( Video ) Unix and Linux History by Jon "maddog" Hall - Jon Hall gives a great rundown on Linux and Unix history in the 50 year period from 1969 to 2019. It's an informal recount mixed with personal experiences and that's exactly what makes it such a compelling watch.

( Video ) The Rise of Unix. The Seeds of its Fall. by Asianometry - A great brief 16-minute video that covers the rise of Unix. Started in the legendary Bell Labs by Ken Thompson and Dennis Ritchie. As a personal note, if you're interested in video essays on technology, economics, business and politics I would highly recommend you explore more of Asianometry's videos.

( Article ) The Early Days of Linux by Lars Wirzenius - In keeping with the theme of historical reading the following article goes over some of the very first days of Linux. Lars witnessed the birth of Linux and he also helped fix some of its first issues.

( Short Rant )✨How does the Unix Philosophy matter in modern times? by dlarge65 - There are many diverging opinions on the Unix philosophy. Some say it is over-idealized and irrelevant in the modern day, others argue that there was maybe a philosophy at one point but practicality won over and so on. While I'm still very much new to Linux I enjoyed this rant which takes on a more balanced stance and viewpoint on the Unix Philosophy. It is too early to give my thoughts on the matter but moving forward I plan on taking the balanced approach.

Section Projects

Project 2 - Your First Wargame -> Over The Wire: Bandit

OTW-Bandit-L0.png

Wargame vs CTFs
If you're like me, you probably thought that the term wargame and CTF were interchangeable but they are 2 different things although they are related.
To Summarize: Capture The Flag (CTF) - Time Limited / Wargame - Not Time Limited
Capture The Flag (CTF) - CTFs are exercises where participants try to find strings, called "flags" which are hidden inside purposefully vulnerable programs or websites,
Wargame
- A cyber-security challenge where competitors must exploit or defend a vulnerability in a system or application to gain or prevent access to a computer system.

In essence CTF's are time-based competitions where people try to come out on top, whereas wargames aren't really time limited or competitions, although they do have CTF style challenges.

For this project your job is to go through The Beginner Wargame - Bandit

Why a wargame?
First off, they are very fun! I was always a bit hesitant to read through man pages, but I found myself going through documentation and scouring man pages all to get that next flag. 
Secondly, they can be very challenging. You'll be forced outside of your comfort zone quite often. Bandit will lead you to explore  concepts in networking, compression, decompression, hex dumps, the shell and more.

Bandit
Bandit is a wargame aimed at beginners. Wargames are usually split into levels. We start at Level 0 and try to reach the end.

Why Bandit?
I was pretty hesitant about doing CTFs, they tend to have a heavy cybersecurity focus, which is important, but at our stage can be a distraction.
However, bandit is the ultimate Linux Lab.
- You will use a variety of new flags for commands you commonly use
- You will get a better grasp on user and file permissions
- You will become more comfortable google searching for Linux information
- You will be forced to read the man pages
- You will cover Networking Topics, Data encoding, compression and decompression
- You will be introduced to git, and its commands
- You will go over shell and CLI behavior

After doing Bandit, I am much more comfortable reading documentation, and I have a better idea on the skills I'm missing as a Linux user. You'll learn a lot doing your first wargame and I hope you'll have as much fun working through it as I did.

Bandit Level - 0

Revision #23
Created 25 November 2023 02:03:52 by 01Blu3
Updated 26 April 2024 16:37:10 by 01Blu3