leibowitz

/*
 * Implementations of asprintf(3) and vasprintf(3) borrowed from musl
 * libc for greater portability to non-GNU systems:
 *
 *     http://git.musl-libc.org/cgit/musl/tree/src/stdio/asprintf.c
 *
 *     http://git.musl-libc.org/cgit/musl/tree/src/stdio/vasprintf.c
 *
 * I think they want me to include a copy of the MIT license as well:
 *
 * ----------------------------------------------------------------------
 * Copyright © 2005-2020 Rich Felker, et al.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * ----------------------------------------------------------------------
 */

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

#include "asprintf.h"

int
asprintf(char **s, const char *fmt, ...)
{
	int ret;
	va_list ap;
	va_start(ap, fmt);
	ret = vasprintf(s, fmt, ap);
	va_end(ap);
	return ret;
}

int
vasprintf(char **s, const char *fmt, va_list ap)
{
	va_list ap2;
	va_copy(ap2, ap);
	int l = vsnprintf(0, 0, fmt, ap2);
	va_end(ap2);

	if (l<0 || !(*s=malloc(l+1U))) return -1;
	return vsnprintf(*s, l+1U, fmt, ap);
}