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/* $NetBSD: setenv.c,v 1.44 2015/01/20 18:31:25 christos 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. 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[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: setenv.c,v 1.44 2015/01/20 18:31:25 christos 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 "local.h"
#ifdef __weak_alias
__weak_alias(setenv,_setenv)
#endif
/*
* setenv --
* Set the value of the environmental variable "name" to be
* "value". If rewrite is set, replace any current value.
*/
int
setenv(const char *name, const char *value, int rewrite)
{
size_t l_name, l_value, length;
ssize_t offset;
char *envvar;
_DIAGASSERT(name != NULL);
_DIAGASSERT(value != NULL);
l_name = __envvarnamelen(name, false);
if (l_name == 0 || value == NULL) {
errno = EINVAL;
return -1;
}
if (!__writelockenv())
return -1;
/* Find slot in the enviroment. */
offset = __getenvslot(name, l_name, true);
if (offset == -1)
goto bad;
l_value = strlen(value);
length = l_name + l_value + 2;
/* Handle overwriting a current environt variable. */
envvar = environ[offset];
if (envvar != NULL) {
if (!rewrite)
goto good;
/*
* Check whether the buffer was allocated via setenv(3) and
* whether there is enough space. If so simply overwrite the
* existing value.
*/
if (__canoverwriteenvvar(envvar, length)) {
envvar += l_name + 1;
goto copy;
}
}
/* Allocate memory for name + `=' + value + NUL. */
if ((envvar = __allocenvvar(length)) == NULL)
goto bad;
if (environ[offset] != NULL)
__freeenvvar(environ[offset]);
environ[offset] = envvar;
(void)memcpy(envvar, name, l_name);
envvar += l_name;
*envvar++ = '=';
copy:
(void)memcpy(envvar, value, l_value + 1);
good:
(void)__unlockenv();
return 0;
bad:
(void)__unlockenv();
return -1;
}
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