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9ff99d22 | 1 | /* Copyright (C) 1991, 1994, 1997-1998, 2000, 2003-2013 Free Software |
5745a7df PE |
2 | Foundation, Inc. |
3 | ||
4 | NOTE: The canonical source of this file is maintained with the GNU C | |
5 | Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu. | |
6 | ||
7 | This program is free software: you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 3 of the License, or any | |
10 | later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include <config.h> | |
21 | ||
22 | /* Specification. */ | |
23 | #include <stdlib.h> | |
24 | ||
25 | #include <stddef.h> | |
26 | ||
27 | /* Include errno.h *after* sys/types.h to work around header problems | |
28 | on AIX 3.2.5. */ | |
29 | #include <errno.h> | |
30 | #ifndef __set_errno | |
31 | # define __set_errno(ev) ((errno) = (ev)) | |
32 | #endif | |
33 | ||
34 | #include <string.h> | |
35 | #include <unistd.h> | |
36 | ||
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37 | #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ |
38 | # define WIN32_LEAN_AND_MEAN | |
39 | # include <windows.h> | |
40 | #endif | |
41 | ||
5745a7df PE |
42 | #if _LIBC |
43 | # if HAVE_GNU_LD | |
44 | # define environ __environ | |
45 | # else | |
46 | extern char **environ; | |
47 | # endif | |
48 | #endif | |
49 | ||
50 | #if _LIBC | |
51 | /* This lock protects against simultaneous modifications of 'environ'. */ | |
52 | # include <bits/libc-lock.h> | |
53 | __libc_lock_define_initialized (static, envlock) | |
54 | # define LOCK __libc_lock_lock (envlock) | |
55 | # define UNLOCK __libc_lock_unlock (envlock) | |
56 | #else | |
57 | # define LOCK | |
58 | # define UNLOCK | |
59 | #endif | |
60 | ||
61 | static int | |
62 | _unsetenv (const char *name) | |
63 | { | |
64 | size_t len; | |
65 | char **ep; | |
66 | ||
67 | if (name == NULL || *name == '\0' || strchr (name, '=') != NULL) | |
68 | { | |
69 | __set_errno (EINVAL); | |
70 | return -1; | |
71 | } | |
72 | ||
73 | len = strlen (name); | |
74 | ||
89bd9d36 PE |
75 | #if HAVE__PUTENV |
76 | { | |
77 | int putenv_result, putenv_errno; | |
78 | char *name_ = malloc (len + 2); | |
79 | memcpy (name_, name, len); | |
80 | name_[len] = '='; | |
81 | name_[len + 1] = 0; | |
82 | putenv_result = _putenv (name_); | |
83 | putenv_errno = errno; | |
84 | free (name_); | |
85 | __set_errno (putenv_errno); | |
86 | return putenv_result; | |
87 | } | |
88 | #else | |
89 | ||
5745a7df PE |
90 | LOCK; |
91 | ||
92 | ep = environ; | |
93 | while (*ep != NULL) | |
94 | if (!strncmp (*ep, name, len) && (*ep)[len] == '=') | |
95 | { | |
96 | /* Found it. Remove this pointer by moving later ones back. */ | |
97 | char **dp = ep; | |
98 | ||
99 | do | |
100 | dp[0] = dp[1]; | |
101 | while (*dp++); | |
102 | /* Continue the loop in case NAME appears again. */ | |
103 | } | |
104 | else | |
105 | ++ep; | |
106 | ||
107 | UNLOCK; | |
108 | ||
109 | return 0; | |
89bd9d36 | 110 | #endif |
5745a7df PE |
111 | } |
112 | ||
113 | ||
114 | /* Put STRING, which is of the form "NAME=VALUE", in the environment. | |
115 | If STRING contains no '=', then remove STRING from the environment. */ | |
116 | int | |
117 | putenv (char *string) | |
118 | { | |
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119 | const char *name_end = strchr (string, '='); |
120 | char **ep; | |
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121 | |
122 | if (name_end == NULL) | |
123 | { | |
124 | /* Remove the variable from the environment. */ | |
125 | return _unsetenv (string); | |
126 | } | |
127 | ||
89bd9d36 PE |
128 | #if HAVE__PUTENV |
129 | /* Rely on _putenv to allocate the new environment. If other | |
130 | parts of the application use _putenv, the !HAVE__PUTENV code | |
131 | would fight over who owns the environ vector, causing a crash. */ | |
132 | if (name_end[1]) | |
133 | return _putenv (string); | |
134 | else | |
135 | { | |
136 | /* _putenv ("NAME=") unsets NAME, so invoke _putenv ("NAME= ") | |
137 | to allocate the environ vector and then replace the new | |
138 | entry with "NAME=". */ | |
139 | int putenv_result, putenv_errno; | |
140 | char *name_x = malloc (name_end - string + sizeof "= "); | |
141 | if (!name_x) | |
142 | return -1; | |
143 | memcpy (name_x, string, name_end - string + 1); | |
144 | name_x[name_end - string + 1] = ' '; | |
145 | name_x[name_end - string + 2] = 0; | |
146 | putenv_result = _putenv (name_x); | |
147 | putenv_errno = errno; | |
148 | for (ep = environ; *ep; ep++) | |
149 | if (strcmp (*ep, name_x) == 0) | |
150 | { | |
151 | *ep = string; | |
152 | break; | |
153 | } | |
154 | # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | |
155 | if (putenv_result == 0) | |
156 | { | |
157 | /* _putenv propagated "NAME= " into the subprocess environment; | |
158 | fix that by calling SetEnvironmentVariable directly. */ | |
159 | name_x[name_end - string] = 0; | |
160 | putenv_result = SetEnvironmentVariable (name_x, "") ? 0 : -1; | |
161 | putenv_errno = ENOMEM; /* ENOMEM is the only way to fail. */ | |
162 | } | |
163 | # endif | |
164 | free (name_x); | |
165 | __set_errno (putenv_errno); | |
166 | return putenv_result; | |
167 | } | |
168 | #else | |
169 | for (ep = environ; *ep; ep++) | |
170 | if (strncmp (*ep, string, name_end - string) == 0 | |
171 | && (*ep)[name_end - string] == '=') | |
5745a7df | 172 | break; |
5745a7df | 173 | |
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174 | if (*ep) |
175 | *ep = string; | |
176 | else | |
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177 | { |
178 | static char **last_environ = NULL; | |
89bd9d36 PE |
179 | size_t size = ep - environ; |
180 | char **new_environ = malloc ((size + 2) * sizeof *new_environ); | |
181 | if (! new_environ) | |
5745a7df | 182 | return -1; |
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183 | new_environ[0] = string; |
184 | memcpy (new_environ + 1, environ, (size + 1) * sizeof *new_environ); | |
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185 | free (last_environ); |
186 | last_environ = new_environ; | |
187 | environ = new_environ; | |
188 | } | |
89bd9d36 | 189 | #endif |
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190 | |
191 | return 0; | |
192 | } |