From: utzoo!decvax!cca!dan@Bbn-Unix@sri-unix
Newsgroups: net.unix-wizards
Title: Re:  %r format item in some printf implementations
Article-I.D.: sri-unix.3346
Posted: Sat Sep 18 02:11:37 1982
Received: Wed Sep 22 10:48:00 1982

From: Dan Franklin 
Date: 15 Sep 1982 16:58:16 EDT (Wednesday)
Having looked at the "varargs stuff", which (in V7) appears to consist solely
of a five-line include file with no comments or other hints as to how it's
supposed to work (and, of course, no documentation), I think I can infer how
it's supposed to be used.  If I understand it correctly, there is already a
format item which accepts a va_list; it's called %r.  For all the UNIX machines
I know about whose printf offers %r format, %r accepts exactly what varargs.h
maintains!  So %r really is portable--it's just that we've all been using it in
a non-portable way up to now.  You just need to change your documentation as to
what it accepts--that is, if you've documented it at all!  (One undocumented
hack deserves another...)