Almost every tool in this curriculum — curl, nmap, sqlmap, nikto, and the whole Kali toolbox — is driven from a Linux command line. Before you can use any of them, you need to feel at home in a terminal: knowing what it is, how the files are organized, how to move around, and how to look at things. This lesson assumes you have never opened a terminal before, and there is nothing to attack — it is pure orientation.
Prerequisites: none beyond hacking-ethics-and-authorization for the course's authorization boundary. linux-basics-part2 builds on this lesson with permissions, packages, and pipelines, and linux-command-line-fundamentals applies those skills to security tasks.
In this lesson you will:
- Learn what a shell is and how a command line is structured — the command, its options (flags), and its arguments — and how to read the prompt.
- Walk the Linux filesystem tree: the root
/, and the directories you will see everywhere —/etc(configuration),/home(your files),/var(logs under/var/log),/tmp(scratch space), and/bin(the programs themselves). - Understand the difference between an absolute path (starts at
/, means the same everywhere) and a relative path (read from where you currently stand), plus the.,.., and~shortcuts. - Meet the core navigation and inspection commands — **
pwd,ls,cd,cat,less,man** — and the file-housekeeping commandstouch,mkdir,cp,mv, andrm. - Pick up two habits that make the shell pleasant: tab-completion and command history.
- Open a shell yourself, navigate to
/etc, list it, read a file, and open a manual page.
This is an orientation, not an exploitation walkthrough. Everything you do here is read-only and local — viewing files on your own machine. That same care about authorization applies the moment you point any tool at a system you do not own; see hacking-ethics-and-authorization.
Estimated time: ten to twelve minutes.
When you are ready, send the Continue signal.