Path: chuka.playstation.co.uk!news
From: James Russell <James_Russell@scee.sony.co.uk>
Newsgroups: scee.yaroze.programming.libraries
Subject: Re: Variable arg list
Date: Fri, 27 Nov 1998 11:05:00 +0000
Organization: Sony Computer Entertainment Europe
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Message-ID: <365E875C.8B7B87FD@scee.sony.co.uk>
References: <73lri0$ngl1@chuka.playstation.co.uk>
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ROBERT C SHAND wrote:
> 
> Hi all,
> 
> Is it possible to setup a variable arg list for functions?, such a those
> found in printf, on the yaroze.  I know these form part of the standard libs
> (as in ANSI) but we only have a subset of these.

Yes - it's fairly easy. Here's an example:
Remember - there's no variable that states how many extra args you have - it has to be specified
either implicitly (as in printf) or explicitly in one of the fixed args. This is a pretty useless
function, but hopefully you get the idea.

#define va_start(AP, LASTARG)                                           \
 (AP = ((char *)&(LASTARG) + __va_rounded_size(LASTARG)))

#define va_end(AP) AP = (char *)NULL

#define va_arg(AP, TYPE)                                                \
 (AP = ((char *) (AP)) += __va_rounded_size (TYPE),                     \
  *((TYPE *) ((char *) (AP) - __va_rounded_size (TYPE))))

typedef void *va_list;



	// Convert all passed strings to upper case before printing.
	// usage:

	// printff("Abcdef : %s  abc: %d",myString,100);  // follow this with.
	// printf("Abcdef : %s  abc: %d",myString,100);
void printff(char *s, ...) {
    va_list ap;
    int argnum;
    char *p,**a;
    static char strbuffer[1000];

    va_start(ap, s);

	argnum = 0;
	a = (char **)ap;
    for(p = s; *p != 0; p++) {
        if(p[0] == '%') {
		if(p[1] == 's') {
			makeUpperCase(a[argnum]);
		}
		argnum++;
		p++;
        }
	p++;
    }

    a = (char **)ap;
    va_end(ap);
}


-- 
== James_Russell@scee.sony.co.uk                +44 (171) 447-1626
== Developer Support Engineer - Sony Computer Entertainment Europe

Programming is an art form that fights back.