Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!decvax!dartvax!eleazar!cmi
From: cmi@eleazar.Dartmouth.EDU (Theo Pozzy/R. Green)
Newsgroups: comp.lang.c
Subject: problems with varargs
Message-ID: <7962@eleazar.Dartmouth.EDU>
Date: 20 Jan 88 21:26:28 GMT
Reply-To: cmi@eleazar.Dartmouth.EDU (Theo Pozzy/R. Green)
Organization: Corporate Microsystems, Inc.
Lines: 58
Keywords: varargs
References:


I'm have a problem working with the standard *nix varargs construct.
What I'm basically trying to do is implement two levels of variable
argument passing, similar to what the vprintf() routine must be doing.
Now, I don't have the sources to vprintf, and I don't know if it can
be done portably in the context of the varargs guidelines.

The basic idea is to have a routine like printf(), which calls another
routine, like fprintf(), passing one argument in addition to the arguments
passed to it.  The first routine to get called, which works fine, looks
like this:

myprintf(fmt, va_alist)
char *fmt;
va_dcl
{
va_list vap;

va_start(vap);

/* here I can pull of the arguments with no problem */

myfprintf(stdout,fmt,vap);

va_end(vap);

}

Here's what I've tried, which doesn't work, for myfprintf():

myfprintf(f, fmt, va_alist)
FILE *f;
char *fmt;
va_dcl
{
va_list vap;

va_start(vap);

/* at this point, the va_arg() routine doesn't return the arguments correctly */
va_end(vap)

}

Is there anyone out there who has a good handle on varargs that can tell
me the right (portable) way to do this?  Is there someone with the source
to vprintf() with some insight?

Thanks,

Theo Pozzy, Corporate Microsystems, Inc.
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-- 
Theo Pozzy, Corporate Microsystems, Inc.
...!decvax!dartvax!eleazar!cmi (UUCP)      cmi@eleazar.dartmouth (CSNET)
cmi%eleazar@dartmouth.edu      (ARPA)      Box A-58, Hanover, NH, 03755 (USPS)
CompuServe                     (76267,413) (603) 448-5193 (BellNet)