1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 1996, by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27 /*
28 * MKS interface extension.
29 * A version of getenv() that doesn't overwrite it's return value
30 * on each call.
31 *
32 * Copyright 1995 by Mortice Kern Systems Inc. All rights reserved.
33 *
34 */
35
36 #ifdef M_RCSID
37 #ifndef lint
38 static char const rcsID[] = "$Header: /rd/src/libc/mks/rcs/m_getenv.c 1.2 1995/07/11 16:53:01 ross Exp $";
39 #endif /*lint*/
40 #endif /*M_RCSID*/
41
42 #include <mks.h>
43 #include <stdlib.h>
44 #include <string.h>
45
46 #ifdef M_NON_STATIC_GETENV
47
48 #undef __m_getenv
49
50 /*f
51 * Assume getenv() works the way we expect it to on PC systems.
52 */
53 char *
__m_getenv(char const * name)54 __m_getenv(char const *name) {
55 return getenv(name);
56 }
57
58 #else /* M_NON_STATIC_GETENV */
59
60 extern char **environ;
61
62 /*f
63 * A version of getenv safe to use in library functions. According to
64 * ANSI C and XPG 4 no library function shall behave as if it called
65 * getenv. This is a problem on systems that have getenv functions
66 * that overwrite their return value on each call.
67 */
68
69 char *
__m_getenv(char const * name)70 __m_getenv(char const *name) {
71 if (m_setenv() != NULL) {
72 int len = strlen(name);
73 char **envp = environ;
74 char *s = *envp++;
75
76 while(s != NULL) {
77 if (strncmp(name, s, len) == 0 && s[len] == '=') {
78 return s + len + 1;
79 }
80 s = *envp++;
81 }
82 }
83 return NULL;
84 }
85
86 #endif /* M_NON_STATIC_GETENV */
87