Linux & the Command Line
The operating system behind most servers and security tooling, and how to drive it from the terminal.
1. Introduction to Linux
Why Linux matters for security work: it runs almost every server on the internet, and it's operated through the terminal.
2. Navigating the Filesystem
pwd, ls, and cd, finding out where you are, seeing what's around you, and moving between folders.
3. Working with Files
mkdir, touch, cp, mv, and rm, creating, copying, renaming, and removing, and why rm has no undo.
4. Viewing & Editing Files
cat, less, and nano, reading and editing text without leaving the terminal.
5. Permissions
chmod and chown, controlling who can read, write, and execute a file, and why misconfigured permissions are a real security issue.
6. Processes
ps, top, and kill, seeing what's running on a machine, and stopping something that's misbehaving.
7. Piping & Redirection
Chaining commands together with | and sending output to a file with >, the idea that makes the command line genuinely powerful.
8. Package Management
Installing and updating software from the command line, apt on Debian/Ubuntu, and why updating first matters.