Backplot application - command line prefered

Hi,

I would like to display g-code tool paths as a bitmap or jpeg (or any
popular web-able graphic format).

Is there a simple Windows based program that will do this with
command line inputs? How about something that will run on Linux?

If there are none that will run with a command line input, I could
deal with one that has a minimal point and click interface.

I started to write one myself, but the task is a little bit over my
head.

Thanks,

Dan b