102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
/* $NetBSD: getenv.c,v 1.17 2003/08/07 16:43:39 agc 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 1.17 2003/08/07 16:43:39 agc Exp $");
|
|
#endif
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "local.h"
|
|
#include "reentrant.h"
|
|
|
|
#ifdef _REENTRANT
|
|
rwlock_t __environ_lock = RWLOCK_INITIALIZER;
|
|
#endif
|
|
extern char **environ;
|
|
|
|
/*
|
|
* getenv --
|
|
* Returns ptr to value associated with name, if any, else NULL.
|
|
*/
|
|
char *
|
|
getenv(name)
|
|
const char *name;
|
|
{
|
|
int offset;
|
|
char *result;
|
|
|
|
_DIAGASSERT(name != NULL);
|
|
|
|
rwlock_rdlock(&__environ_lock);
|
|
result = __findenv(name, &offset);
|
|
rwlock_unlock(&__environ_lock);
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* __findenv --
|
|
* Returns pointer to value associated with name, if any, else NULL.
|
|
* Sets offset to be the offset of the name/value combination in the
|
|
* environmental array, for use by setenv(3) and unsetenv(3).
|
|
* Explicitly removes '=' in argument name.
|
|
*
|
|
* This routine *should* be a static; don't use it.
|
|
*/
|
|
char *
|
|
__findenv(name, offset)
|
|
const char *name;
|
|
int *offset;
|
|
{
|
|
size_t len;
|
|
const char *np;
|
|
char **p, *c;
|
|
|
|
if (name == NULL || environ == NULL)
|
|
return (NULL);
|
|
for (np = name; *np && *np != '='; ++np)
|
|
continue;
|
|
len = np - name;
|
|
for (p = environ; (c = *p) != NULL; ++p)
|
|
if (strncmp(c, name, len) == 0 && c[len] == '=') {
|
|
*offset = p - environ;
|
|
return (c + len + 1);
|
|
}
|
|
return (NULL);
|
|
}
|