ps - How to check the running processes on Linux

ps, is a Linux command tool, that lets you view the current running processes, it is very useful when you are trying to kill a process or to view which applications other users are running (if you are the admin).

You may use it to check your own applications, some other user's application or a full list of the applications running on the operating system, you may also combine it with grep.

running it alone with no atributes

ps

Will give your actual running applications.

 6999 pts/1    00:00:00 bash
 7099 pts/1    00:00:00 ps

notice, that those are the running applications in that given console, so if you have a lot of running virtual terminals, it will only list those running (started from) that give one.

If you want to check all the processes you are running, enter:

ps -u username

Where username is your username.

The output for me now is:

 PID TTY          TIME CMD
 3270 ?        00:00:00 gnome-session
 3316 ?        00:00:00 ssh-agent
 3319 ?        00:00:00 dbus-launch
 3320 ?        00:00:00 dbus-daemon
 3325 ?        00:00:00 gconfd-2
 3328 ?        00:00:00 gnome-keyring-d
 3330 ?        00:00:05 gnome-settings-
 3345 ?        00:00:16 gnome-screensav
 3346 ?        00:00:05 openbox
 3347 ?        00:00:31 gnome-panel
 3349 ?        00:00:03 nautilus
 3352 ?        00:00:00 bonobo-activati
 3358 ?        00:00:00 bluetooth-apple
 3361 ?        00:00:00 update-notifier
 3369 ?        00:00:00 gnome-vfs-daemo
 3372 ?        00:00:00 gnome-volume-ma
 3381 ?        00:00:00 gnome-power-man
 3409 ?        00:00:00 mapping-daemon
 3418 ?        00:00:00 mixer_applet2
 3457 ?        00:15:43 firefox-bin
 3530 ?        00:00:04 notification-da
 3544 ?        00:00:00 icedove
 3556 ?        00:00:00 run-mozilla.sh
 3561 ?        00:01:00 icedove-bin
 3579 ?        00:00:06 gnome-terminal
 3582 ?        00:00:00 gnome-pty-helpe
 3583 pts/0    00:00:00 bash
 3617 pts/0    00:00:00 ssh
 3707 ?        00:00:09 gftp-gtk
 6999 pts/1    00:00:00 bash
 7100 pts/1    00:00:00 ps

The first column shows the PID the second the terminal where the process is running, the third, the time it is running and the last one the name of the application.

To check all running applications, enter

ps -e

another good option is:

ps aux

Which will be like the above one, but will also shows you the CPU and Memory load that every process is charging on the PC.

check man ps, to view more options and examples.