Unit 3 路 Linux^2 路 Lesson 29 of 34
Kill
No penguins were harmed in the making of this lesson. 馃惂
Every program running on your computer right now is called a process. Your browser, your music, the terminal you're typing in, all processes. Each one gets its own ID number called a PID (process ID).
Seeing what's running
To see what's running, use ps:
Since ps aux is a lot, you'll usually pipe it into grep to find what you're looking for:
[user@linux]$ ps aux | grep firefox
Killing a process
Sometimes a program freezes and just refuses to close. That's when you kill it.
鈿狅笍 Always try plain
killfirst.-9is the "I'm not asking anymore" option, and the program doesn't get a chance to save anything before it goes down.
Live view with top
If you want a live view that updates every couple seconds (kind of like Task Manager on Windows), try top.
[user@linux]$ top
Press q to get out of it.
Your turn
A process called hostage is running in your box, and it's holding a flag. Find its PID and stop it, but stop it nicely, or it takes the flag down with it.
Capture-the-flag challenge
Put the lesson to work on a challenge and submit the flag you find. Create a free account to do this part.
Do this lesson for real
With a free account you get the terminal, the challenges and the checks that go with every lesson in Intro to Linux, and your progress is saved as you go. CyberAcad is a 501(c)(3) nonprofit, so there is nothing to pay.