NetBSD/lib/libc/stdlib/__unsetenv13.c

107 lines
3.2 KiB
C

/* $NetBSD: __unsetenv13.c,v 1.2 2003/04/13 17:39:13 kleink Exp $ */
/*
* Copyright (c) 1987, 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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[] = "from: @(#)setenv.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: __unsetenv13.c,v 1.2 2003/04/13 17:39:13 kleink Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "local.h"
#include "reentrant.h"
#ifdef __weak_alias
#ifdef __LIBC12_SOURCE__
__weak_alias(unsetenv,_unsetenv)
#endif
#endif
#ifdef _REENTRANT
extern rwlock_t __environ_lock;
#endif
#ifdef __LIBC12_SOURCE__
__warn_references(unsetenv,
"warning: reference to compatibility unsetenv();"
" include <stdlib.h> for correct reference")
#endif
extern char **environ;
/*
* unsetenv(name) --
* Delete environmental variable "name".
*/
#ifdef __LIBC12_SOURCE__
void
#else
int
#endif
unsetenv(name)
const char *name;
{
char **p;
int offset;
_DIAGASSERT(name != NULL);
#ifndef __LIBC12_SOURCE__
if (name == NULL || *name == '\0' || strchr(name, '=') != NULL) {
errno = EINVAL;
return (-1);
}
#endif
rwlock_wrlock(&__environ_lock);
while (__findenv(name, &offset)) /* if set multiple times */
for (p = &environ[offset];; ++p)
if (!(*p = *(p + 1)))
break;
rwlock_unlock(&__environ_lock);
#ifndef __LIBC12_SOURCE__
return (0);
#endif
}