ps command to control your linux system

Commands to control your system

ps

'ps' will give you a list of the processes running on your system.

Just typing ps will give you the processes you're running as a user. It may look like this:

PID	TTY	STAT	TIME	COMMAND
293	2	S	0:00	-bash
1436	2	S	0:00	sh /usr/X11R6/bin/startx
1437	2	S	0:00	tee /home/bob/.X.err
1445	2	S	0:00	xinit /home/bob/.xinitrc--
1449	2	S	0:01	/usr/X11R6/bin/fvwm2
1459	2	S	0:00	/usr/X11R6/lib/X11/fvwm2/FvwmButtons7 4 .fvwm2rc 0 8
1461	2	S	0:00	xclock -digital -FONT10x20 -geometry +520+550
1462	2	S	0:00	/usr/X11R6/lib/X11/fvwm2/FvwmPager9 4 .fvwm2rc 0 8 0 0 &
1464	2	S	1:27	/opt/netscape/netscape
1472	2	S	0:00	(dns helper)
1730	2	S	0:00	xterm -FONT 8x13 -backgroundWheat -T xterm-1
1731	p1	S	0:00	bash
1760	2	S	0:01	emacs
1781	p1	R	0:00	ps

If you happen to forget what your name is, you can type ps -u. This is the user mode and your user name will appear in the first column. Actually, there's more than that. There will be other columns about memory usage, the time you started running the processes and others.

You can see other users processes if you type ps -au. If you're not using a networked computer, you will see yours and root's processes. If you're into detective work, you can type just ps -a and try to guess who's using the process.

The information that you'll probably be most interested in is the column that shows the "process ID" or "PID". We'll get into why these are so important in the next part of the lesson.