sfprints.c

来自「su 的源代码库」· C语言 代码 · 共 48 行

/* Copyright (c) Colorado School of Mines, 2006.*/
/* All rights reserved.                       */

#include	"sfhdr.h"

/*	Construct a string with the given format and data.
**	This function allocates space as necessary to store the string.
**	This avoids overflow problems typical with sprintf() in stdio.
**
**	Written by Kiem-Phong Vo.
*/

#if __STD_C
char* sfprints(const char* form, ...)
#else
char* sfprints(va_alist)
va_dcl
#endif
{
	va_list		args;
	reg int		rv;
	static Sfio_t*	f;

#if __STD_C
	va_start(args,form);
#else
	reg char	*form;
	va_start(args);
	form = va_arg(args,char*);
#endif

	/* make a fake stream */
	if(!f &&
	   !(f = sfnew(NIL(Sfio_t*),NIL(char*),(size_t)SF_UNBOUND,
			-1,SF_WRITE|SF_STRING)) )
		return NIL(char*);

	sfseek(f,(Sfoff_t)0,0);
	rv = sfvprintf(f,form,args);
	va_end(args);

	if(rv < 0 || sfputc(f,'\0') < 0)
		return NIL(char*);

	_Sfi = (f->next - f->data) - 1;
	return (char*)f->data;
}