I am having a recurring problem trying to install a relatively small port x11/nvidia-settings in that it keeps freezing right below the line that ends with "-o shader/arbprogparse.o". I am not sure what is causing the port to fail installation but the main problem I have is that I don't know how to interrupt or abort the port installation and just go back to the shell prompt. I want to know if there is a way to stop a process like port installation so that the machine can be shutdown or restarted properly.