Foundations

This book starts with an empty terminal. By the end of the first part you will move around the filesystem without thinking, read and edit files, chain commands into pipelines, and find answers yourself in man. This is the foundation. Without it, the administration in Part II turns into memorizing commands by rote. With it, the same work becomes something you understand.

Who this is for. You have opened a terminal once or twice and closed it. Or never opened it at all. You have no Linux experience, and that is fine. The book is written for exactly this start.

What you need. A Linux system where you can make mistakes without consequences. Three options:

• A virtual machine (VirtualBox, UTM, VMware) with Ubuntu or Fedora. The safest path: break it, roll back the snapshot.
• WSL2 on Windows: wsl --install in PowerShell puts Ubuntu inside Windows.
• A container: docker run -it ubuntu bash, if you already have Docker.

For a beginner I recommend a virtual machine or WSL2. A container is more convenient once you find your footing.

How to read. Chapters go in order, each builds on the previous one. You can jump ahead, but the early chapters are best read in sequence. Inside chapters you will find "how it works" boxes. That is a second layer for those curious about how things work underneath. You can skip them and come back later. Each chapter ends with exercises and a short summary.

Conventions. Commands are set in monospace. The $ at the start of a line is the shell prompt for a regular user; you do not type it. A # would mean the root (superuser) prompt. We do not work as root yet: Part I does not need it, and it only adds risk.