Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!adm!mrose@twg.arpa
From: mrose@twg.arpa (Marshall Rose)
Newsgroups: comp.unix.wizards
Subject: (simple?) varargs question
Message-ID: <10937@brl-adm.ARPA>
Date: 21 Dec 87 17:24:37 GMT
Sender: news@brl-adm.ARPA
Lines: 40


     I am trying to retrofit some code to use <varargs.h> and have hit a
     problem.  Perhaps some portability expert out there can help me
     out.

     The problem is that I want to be able to do upto several levels of
     nesting of routines with variable arguments.  The hierarchy is like
     this:

		pktlose
		   |
		   |
		   |
		   |
		saplose				xsprintf
		   |				    |
		   |				    |
		   |				    |
		   |				    |
		   +--------------------------------+
				    |
				    |
				    |
				    |
				 asprintf

     Each of these routines starts with a fixed number of arguments,
     followed by a format string and then a variable number of
     arguments.  Ultimately asprintf will call vsprintf or _doprnt to
     format a string.  The trick here is figuring out the declaration
     and calling sequences of each of these routines since asprintf can
     be called either 2 or 3 levels deep from the routine which actually made
     a call with variable arguments.

     The man page for varargs gives a cryptic reference to nesting, but
     is essentially undecipherable.

Thanks in advance,

/mtr