1 /* $NetBSD: getenv.c,v 1.35 2010/11/14 22:04:36 tron Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: getenv.c,v 1.35 2010/11/14 22:04:36 tron Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include <assert.h> 43 #include <errno.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #include "env.h" 48 #include "reentrant.h" 49 #include "local.h" 50 51 __weak_alias(getenv_r, _getenv_r) 52 53 /* 54 * getenv -- 55 * Returns ptr to value associated with name, if any, else NULL. 56 * XXX: we cannot use getenv_r to implement this, because getenv() 57 * cannot use a shared buffer, because if it did, subsequent calls 58 * to getenv would trash previous results. 59 */ 60 char * 61 getenv(const char *name) 62 { 63 size_t l_name; 64 char *result; 65 66 _DIAGASSERT(name != NULL); 67 68 l_name = __envvarnamelen(name, false); 69 if (l_name == 0) 70 return NULL; 71 72 result = NULL; 73 if (__readlockenv()) { 74 result = __findenvvar(name, l_name); 75 (void)__unlockenv(); 76 } 77 78 return result; 79 } 80 81 int 82 getenv_r(const char *name, char *buf, size_t len) 83 { 84 size_t l_name; 85 int rv; 86 87 _DIAGASSERT(name != NULL); 88 89 l_name = __envvarnamelen(name, false); 90 if (l_name == 0) { 91 errno = ENOENT; 92 return -1; 93 } 94 95 rv = -1; 96 if (__readlockenv()) { 97 const char *value; 98 99 value = __findenvvar(name, l_name); 100 if (value != NULL) { 101 if (strlcpy(buf, value, len) < len) { 102 rv = 0; 103 } else { 104 errno = ERANGE; 105 } 106 } else { 107 errno = ENOENT; 108 } 109 (void)__unlockenv(); 110 } 111 112 return rv; 113 } 114