I'll assume that you started a process in Linux, on an actual SCC core (If that's not the case, please provide more context):
If you started a process "myCmd" in foreground, CTRL-C should end it... You could doublecheck with "ps -edafl | grep myCmd". You shouldn't get a match if the process is closed. If the process still runs, the ps command will show you the PID (number behind user name) and you can stop the application with "kill -9 <PID>"... So, as you can see, this is a regular Linux shell (running ash).
I also used this command:
pssh -P -h ./allhosts -p 48 -t -1 ps