Given your pursuit of elegance, I imagine you could ultimately have a --clone or --cloner command-line switch which would allow any executable instance based upon your interpreter to create a new executable instance, but encapsulating newly-supplied source code. In this sense your interpreter could go viral. (In tcl/tk context, freeWrap might be an example for study.)

Relatedly, I don't know whether, given argv[0] and your targets, one can at least copy the named file, even if one cannot open it directly for reading.