Linux for OSINT. 21-day course for beginners
Please note that you need to download the PDF file to take the course!
UPD: 06 January 2026
This course was written back in the good old days when Gitpod offered users 50 hours of free work per month. But that was a long time ago, and now this service has become paid.
Fortunately, you can still execute the commands from this course in Github Codespace.
To do this:
- Log in to Github and open the course repository page (Linux for OSINT or Python for OSINT).
- Click Code -> Create codespace on main.
- Wait a moment and start using the working environment in the same way as Gitpod (as described in the PDF).
There may be some limitations, but this is sufficient for a general introduction to the course. And remember that you can always just use any Ubuntu-based Linux VM on your computer to take the course.
Who Is This Course For?
The course is primarily intended for those who are professionally involved in or simply interested in OSINT. And you will find in it a lot about automation of collection and analysis of various data.
On my Twitter (https://twitter.com/cyb_detective) account, I regularly write about useful tools for OSINT, including various Linux utilities. And many times readers have asked, "Cool! Is it possible to run this on Windows?".
Yes, there are different methods of running Linux utilities on Windows. But they are more complicated than running Linux on a VM (virtual machine), VPS (virtual private server) or in an online development environment.
This short tutorial is created to show you clearly that:
- Linux and the command line are very easy to use. Really easy. Extremely easy.
- hundreds of tasks (OSINT related and not only) can be simplified and automated with Linux.
- using Linux command line is a real, unparalleled pleasure.
This course is designed for the total beginners. I won't even ask you to install a VM with Linux until the last day, all examples can be tried in a browser. You also won't need any special knowledge. If you know how to use e-mail, you will be able to handle this course. Just relax and follow the instructions carefully.
When reading, keep in mind that this is a short course and so many things are left out. And really important things have been left out. It is designed primarily to show you the capabilities of Linux and to show you "which way to look" when faced with different tasks.
Who should avoid this course?
Linux is good because you can solve the same problem in many different ways. I am not sure that the ways described in this course are the best and fastest ways to solve problems. They are written to visually show you the magic of the command line and stimulate your inner inventor (but all examples work and solve the stated problems).
I would advise the following categories of readers to treat this book as critically as possible and certainly read other Linux books:
- students who are preparing for exams
- IT specialists who are preparing for Linux-related job interviews
- people who want to become real Linux experts
- pentesters and bug hunters
This book is primarily about OSINT.
Day 0. Getting ready to work
Eric Raymond, in his article “How to become a hacker” (1 December 1997, https://cs.fit.edu/~wds/classes/cdc/Readings/BecomeAHacker.pdf), recommended going to a local Linuxoid meeting and asking to burn discs of some distro in exchange for beer (I found this article, but link "where to get Linux" no longer working now).
In the last 26 years progress has gone a long way and I'll just ask you to open a new tab in your browser.
Gitpod is a service that provides online development environments based on the Linux distribution Ubuntu (https://ubuntu.com). You can use it for 50 hours a month for free. This is definitely enough time for you to take this course many times.
You should use a Github (https://github.com/) account for authorization (registration is very fast and also free).
Open this link and create a workspace with standard settings:
https://gitpod.io#https://github.com/cipher387/linux-for-OSINT-21-day
If you are already using some Linux distribution, you can simply clone the https://github.com/cipher387/linux-for-OSINT-21-day repository to your computer or server.
If you don't know how to clone repositories yet, I recommend using Gitpod for now. On Day 19 you will learn how to clone repositories, and on Day 21 you will think about which Linux distribution is best for you.
Please note that you need to download the PDF file to take the course!
Table of contents
Who Is This Course For?
Who should avoid this course?
Day 0. Getting ready to work
Day 1. Basic skills of working with files and directories in command line
Day 2. Basic bash script syntax
Day 3. Install and run utilities
Day 4. Batch file processing
Day 5. Downloading files and working with APIs. Curl.
Day 6. Search in files. Grep
Day 7. Sed and Awk
Day 8. Vim text editor
Day 9. Screen and Crone
Day 10. Text analyzing and editing utilities
Day 11. Video, audio and images
Day 12. Analyze PDF
Day 13. MS Office files
Day 14. JSON, XML, CSV
Day 15. Scraping
Day 16. Web search automation tools
Day 17. File sharing sites, torrents, FTP
Day 18. Domain investigation
Day 19. Git and Github
Day 20. Tools to make Linux easier to use
Day 21. Which Linux distribution is better to use?
What to do next?
Application. Is it possible to do the same thing on Windows?
My first course:
Python for OSINT. 21-day course for beginners
Thank you for following me! https://cybdetective.com
