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5e8754f9 | 1 | /* Copyright (C) 1992, 1995-2002, 2005-2016 Free Software Foundation, Inc. |
3d99e817 AK |
2 | This file is part of the GNU C Library. |
3 | ||
4 | This program is free software: you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 3 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
5e8754f9 | 15 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3d99e817 AK |
16 | |
17 | /* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc | |
18 | optimizes away the name == NULL test below. */ | |
19 | #define _GL_ARG_NONNULL(params) | |
20 | ||
21 | #include <config.h> | |
22 | ||
23 | /* Specification. */ | |
24 | #include <stdlib.h> | |
25 | ||
26 | #include <errno.h> | |
27 | #if !_LIBC | |
28 | # define __set_errno(ev) ((errno) = (ev)) | |
29 | #endif | |
30 | ||
31 | #include <string.h> | |
32 | #include <unistd.h> | |
33 | ||
34 | #if !_LIBC | |
35 | # define __environ environ | |
36 | #endif | |
37 | ||
38 | #if _LIBC | |
39 | /* This lock protects against simultaneous modifications of 'environ'. */ | |
40 | # include <bits/libc-lock.h> | |
41 | __libc_lock_define_initialized (static, envlock) | |
42 | # define LOCK __libc_lock_lock (envlock) | |
43 | # define UNLOCK __libc_lock_unlock (envlock) | |
44 | #else | |
45 | # define LOCK | |
46 | # define UNLOCK | |
47 | #endif | |
48 | ||
49 | /* In the GNU C library we must keep the namespace clean. */ | |
50 | #ifdef _LIBC | |
51 | # define unsetenv __unsetenv | |
52 | #endif | |
53 | ||
54 | #if _LIBC || !HAVE_UNSETENV | |
55 | ||
56 | int | |
57 | unsetenv (const char *name) | |
58 | { | |
59 | size_t len; | |
60 | char **ep; | |
61 | ||
62 | if (name == NULL || *name == '\0' || strchr (name, '=') != NULL) | |
63 | { | |
64 | __set_errno (EINVAL); | |
65 | return -1; | |
66 | } | |
67 | ||
68 | len = strlen (name); | |
69 | ||
70 | LOCK; | |
71 | ||
72 | ep = __environ; | |
73 | while (*ep != NULL) | |
74 | if (!strncmp (*ep, name, len) && (*ep)[len] == '=') | |
75 | { | |
76 | /* Found it. Remove this pointer by moving later ones back. */ | |
77 | char **dp = ep; | |
78 | ||
79 | do | |
80 | dp[0] = dp[1]; | |
81 | while (*dp++); | |
82 | /* Continue the loop in case NAME appears again. */ | |
83 | } | |
84 | else | |
85 | ++ep; | |
86 | ||
87 | UNLOCK; | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | #ifdef _LIBC | |
93 | # undef unsetenv | |
94 | weak_alias (__unsetenv, unsetenv) | |
95 | #endif | |
96 | ||
97 | #else /* HAVE_UNSETENV */ | |
98 | ||
99 | # undef unsetenv | |
100 | # if !HAVE_DECL_UNSETENV | |
101 | # if VOID_UNSETENV | |
102 | extern void unsetenv (const char *); | |
103 | # else | |
104 | extern int unsetenv (const char *); | |
105 | # endif | |
106 | # endif | |
107 | ||
108 | /* Call the underlying unsetenv, in case there is hidden bookkeeping | |
109 | that needs updating beyond just modifying environ. */ | |
110 | int | |
111 | rpl_unsetenv (const char *name) | |
112 | { | |
113 | int result = 0; | |
114 | if (!name || !*name || strchr (name, '=')) | |
115 | { | |
116 | errno = EINVAL; | |
117 | return -1; | |
118 | } | |
119 | while (getenv (name)) | |
120 | # if !VOID_UNSETENV | |
121 | result = | |
122 | # endif | |
123 | unsetenv (name); | |
124 | return result; | |
125 | } | |
126 | ||
127 | #endif /* HAVE_UNSETENV */ |