01step · watch first

A guided tour before you touch the terminal.

A five-minute intro to the Linux command line — the same commands you'll use to hunt down the flag inside the lab. Watch it all the way through, then move on to the animated simulation to see the same ideas in action.

▶ Lesson · Command-line basics ~5 min

≡ Summary what to remember

1The cursor is a question. Every line waits for you to type a command, press Enter, and read the answer. There's no "submit" button — just the blinking cursor.
2Three commands cover most of it. ls shows what's in a folder. cd moves you into a folder. pwd tells you which folder you're in. Get these down before anything else.
3Hidden files start with a dot. ls skips them; ls -a shows them all. Your home folder is full of them.
4find searches every folder. When you don't know where a file lives, find / -name "*flag*" checks every folder for a matching name.
5grep finds the words. grep -r 'pattern' /path reads inside every file under /path and prints any line that contains the word you asked for. Chain two of these together and you've solved most beginner labs.

easy 100 xp ~20 min track · CODE

? Quick check · before you continue 1 question · pick one

QYou're dropped into a fresh Linux terminal and told "the flag is hidden somewhere on this machine." Which command is the most useful first move?