linux command related with process

$ps
    to see currently running process
$kill 1012    #kill {PID}
    to stop any process by PID i.e. to kill process
$killall http    #killall {Process-name}
    to stop processes by name i.e. to kill process
$ps -ag
    to get information about all running process
$kill 0
    to stop all process except your shell
$ls | wc -l &    #linux-command &
    for background processing
$ps aux
    to disply the owner of the processes along with the processes
$ps ax | grep http   #ps ax | grep process-U-want-to see
    to see if a particular process is runing or not. For this purpose you have to use
    ps command in combination with the grep command
$top
    to see currently running processes and other information like memory and
    CPU usage with real time updates.
$pstree
    to display a tree of processes