The ps command in Linux explained
The ps command lists running processes at one moment. It is one of the most useful commands for anyone using a live USB drive or a fresh Linux install.
Syntax
ps aux
Examples
ps aux | grep firefox: find a program's process
Tip
The second column is the process ID you give to kill.
Keep learning
New to the terminal? Start with Linux terminal basics. You can try every command safely from a live session: see how to try Linux without installing it. Run man ps in a terminal for the full manual.
Frequently asked questions
How do I see every option for ps?
Run man ps for the full manual, or try ps --help for a short summary.
Do I need sudo to run ps?
Not for your own files. You only need sudo when the command changes something owned by the system or another user.
Is it safe to practise ps on a live USB drive?
Mostly yes, because a live session starts fresh each time. Be careful with commands that write to your internal disk, such as rm on a mounted drive or dd.