/*
 * asprintf.c -- basic port of asprintf / vsprintf functions
 *
 * Copyright (c) 2011, 2012 David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

#define BASE	80	

int
vasprintf(char **res, const char *format, va_list ap)
{
	int rvalue, ok;
	size_t base = BASE;

	if ((*res = malloc(base)) == NULL)
		return -1;

	ok = 0;
	do {
		rvalue = vsnprintf(*res, base, format, ap);

		if ((signed int)base <= rvalue || rvalue < 0) {
			*res = realloc(*res, base + BASE);
			base += BASE;
		} else
			ok = 1;
	} while (!ok && *res != NULL);

	return rvalue;
}

int
asprintf(char **res, const char *fmt, ...)
{
	va_list ap;
	int rvalue;

	va_start(ap, fmt);
	rvalue = vasprintf(res, fmt, ap);
	va_end(ap);

	return rvalue;
}