01step · watch first

A quick primer before you touch the terminal.

A quick primer on the Linux command line — the same commands you'll use to hunt down the flag inside the lab. Skim the summary, then move on to the animated simulation to see the same ideas in action.

≡ 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?