I need to be able to execute sage commands via the command line without opening the Sage shell. I am currently doing this through "sage -c 'cmd'". The issue I have is that this forces all of sage to boot up, run the command, and then shutdown. Something simple as "sage -c "print(derivative(5*x,x))" takes 3-4 seconds to run. How would I speed this up? My idea was to somehow run Sage in the background and be able to feed it input but I am not sure how to do that. I am feeding the command line input from an external program.