lib/libc/stdlib/putenv.c
/*	$NetBSD: putenv.c,v 1.19 2010/11/14 18:11:43 tron Exp $	*/

/*-
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)putenv.c	8.2 (Berkeley) 3/27/94";
#else
__RCSID("$NetBSD: putenv.c,v 1.19 2010/11/14 18:11:43 tron Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include "namespace.h"

#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "env.h"
#include "reentrant.h"
#include "local.h"

#ifdef __weak_alias
__weak_alias(putenv,_putenv)
#endif

int
putenv(char *str)
{
	size_t l_name;
	int rv;

	_DIAGASSERT(str != NULL);

	l_name = __envvarnamelen(str, true);
	if (l_name == 0) {
		errno = EINVAL;
		return -1;
	}

	rv = -1;
	if (__writelockenv()) {
		ssize_t offset;

		offset = __getenvslot(str, l_name, true);
		if (offset != -1) {
			if (environ[offset] != NULL)
				__freeenvvar(environ[offset]);
			environ[offset] = str;

			rv = 0;
		}

		(void)__unlockenv();
	}

	return rv;
}
