1 /* $NetBSD: getenv.c,v 1.36 2015/01/20 18:31:25 christos 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 1.36 2015/01/20 18:31:25 christos 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 "local.h" 49 50 __weak_alias(getenv_r, _getenv_r) 51 52 /* 53 * getenv -- 54 * Returns ptr to value associated with name, if any, else NULL. 55 * XXX: we cannot use getenv_r to implement this, because getenv() 56 * cannot use a shared buffer, because if it did, subsequent calls 57 * to getenv would trash previous results. 58 */ 59 char * 60 getenv(const char *name) 61 { 62 size_t l_name; 63 char *result; 64 65 _DIAGASSERT(name != NULL); 66 67 l_name = __envvarnamelen(name, false); 68 if (l_name == 0) 69 return NULL; 70 71 result = NULL; 72 if (__readlockenv()) { 73 result = __findenvvar(name, l_name); 74 (void)__unlockenv(); 75 } 76 77 return result; 78 } 79 80 int 81 getenv_r(const char *name, char *buf, size_t len) 82 { 83 size_t l_name; 84 int rv; 85 86 _DIAGASSERT(name != NULL); 87 88 l_name = __envvarnamelen(name, false); 89 if (l_name == 0) { 90 errno = ENOENT; 91 return -1; 92 } 93 94 rv = -1; 95 if (__readlockenv()) { 96 const char *value; 97 98 value = __findenvvar(name, l_name); 99 if (value != NULL) { 100 if (strlcpy(buf, value, len) < len) { 101 rv = 0; 102 } else { 103 errno = ERANGE; 104 } 105 } else { 106 errno = ENOENT; 107 } 108 (void)__unlockenv(); 109 } 110 111 return rv; 112 } 113