minix/lib/nbsd_libc/stdlib/getenv.c

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/* $NetBSD: getenv.c,v 1.35 2010/11/14 22:04:36 tron 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[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: getenv.c,v 1.35 2010/11/14 22:04:36 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"
__weak_alias(getenv_r, _getenv_r)
/*
* getenv --
* Returns ptr to value associated with name, if any, else NULL.
* XXX: we cannot use getenv_r to implement this, because getenv()
* cannot use a shared buffer, because if it did, subsequent calls
* to getenv would trash previous results.
*/
char *
getenv(const char *name)
{
size_t l_name;
char *result;
_DIAGASSERT(name != NULL);
l_name = __envvarnamelen(name, false);
if (l_name == 0)
return NULL;
result = NULL;
if (__readlockenv()) {
result = __findenvvar(name, l_name);
(void)__unlockenv();
}
return result;
}
int
getenv_r(const char *name, char *buf, size_t len)
{
size_t l_name;
int rv;
_DIAGASSERT(name != NULL);
l_name = __envvarnamelen(name, false);
if (l_name == 0) {
errno = ENOENT;
return -1;
}
rv = -1;
if (__readlockenv()) {
const char *value;
value = __findenvvar(name, l_name);
if (value != NULL) {
if (strlcpy(buf, value, len) < len) {
rv = 0;
} else {
errno = ERANGE;
}
} else {
errno = ENOENT;
}
(void)__unlockenv();
}
return rv;
}