ODOC: ps

ps – Report Process Status
Summary :
ps gives a snapshot of the current processes. Lot of info, like CPU and MEM Usage, PID, UID, Status,…, about the present status of the process will be available in the ps output. ps can also be used as a debugging tool.
Example:

$ ps — Show all running in the current terminal.
$ ps -h — Same as above. But with-out header.
$ ps -ux — Show all processes owned by you.
$ ps -U sbharathi — Show all processes owned by sbharathi.
$ pc -C bash — Show all process with name bash.
$ ps -C syslogd -o pid= — Print PID of syslogd.
$ ps -aux — Show all processes including daemons (without tty) with username or UID.
$ ps -jx –sort=uid,-pid — All processes will list in ascending order of UID and each users process will sorted descending order.
$ ps -o start,time,etime -p 100 — Show the current status of the process with PID 100.
$ ps -e -o pid,state,cmd — Show all processes PID, State & Command (Custom output format -o ).
$ ps -ho “Process %a with PID %p is owned by %U” — Custom output.
$ ps -x -o pid,ruser=RealUser -o comm=Command -o stat=Status — Output with custom headers.

Read : man ps

ps, odoc, linux, gnu/linux