Okay, so that's K&R C, and it's not actually compiled any more (because I've been slowly taking this stuff out and replacing it with things that actually work), but still --- the horror, the horror...
That kind of hackery was necessary because K&R C didn't give you any sanctioned way to write your own printf-like functions. ANSI C introduced <stdarg.h>.
Sure. Also, K&R C tended to target platforms with really simple ABIs, where parameters were always passed on the stack and everything was a machine word; so you could get away with this kind of thing.
K&R C actually has a minimalist elegance to it that later versions of C lost. Not that I'm claiming that it's better, of course. But K&R C had a distinct philosophy to it that was definitely its own.
