/*	$NetBSD: getexecpath.c,v 1.2 2026/10/07 20:15:03 christos Exp $	*/
/*-
 * Copyright (c) 2026 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <dlfcn.h>
#include <string.h>
#include <errno.h>
#include <elf.h>

#include "getexecpath.h"

int
getexecpath(char *buf, size_t len)
{
	const AuxInfo *aux;

	for (aux = _dlauxinfo(); aux->a_type != AT_NULL; ++aux)
		if (aux->a_type == AT_SUN_EXECNAME) {
			if (strlcpy(buf, (void *)(intptr_t)aux->a_v, len) < len)
				return 0;
			errno = ERANGE;
			return -1;
		}
	errno = ENOENT;
	return -1;
}

#ifdef TEST
#include <stdio.h>
#include <err.h>
#include <stdlib.h>
#include <limits.h>

int
main(void)
{
	char buf[PATH_MAX];
	if (getexecpath(buf, sizeof(buf)) == -1)
		err(EXIT_FAILURE, "Can't get path");
	printf("%s\n", buf);
	return 0;
}
#endif