1 /* Copyright (C) 1991, 1994, 1997-1998, 2000, 2003-2010 Free Software
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.
7 This program is free software: you can redistribute it and/or modify it
8 under the terms of the GNU Lesser General Public License as published by the
9 Free Software Foundation; either version 3 of the License, or any
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 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 /* Include errno.h *after* sys/types.h to work around header problems
31 # define __set_errno(ev) ((errno) = (ev))
38 # define environ __environ
40 extern char **environ
;
44 /* This lock protects against simultaneous modifications of `environ'. */
45 # include <bits/libc-lock.h>
46 __libc_lock_define_initialized (static, envlock
)
47 # define LOCK __libc_lock_lock (envlock)
48 # define UNLOCK __libc_lock_unlock (envlock)
55 _unsetenv (const char *name
)
60 if (name
== NULL
|| *name
== '\0' || strchr (name
, '=') != NULL
)
72 if (!strncmp (*ep
, name
, len
) && (*ep
)[len
] == '=')
74 /* Found it. Remove this pointer by moving later ones back. */
80 /* Continue the loop in case NAME appears again. */
91 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
92 If STRING contains no `=', then remove STRING from the environment. */
96 const char *const name_end
= strchr (string
, '=');
100 if (name_end
== NULL
)
102 /* Remove the variable from the environment. */
103 return _unsetenv (string
);
107 for (ep
= environ
; *ep
!= NULL
; ++ep
)
108 if (!strncmp (*ep
, string
, name_end
- string
) &&
109 (*ep
)[name_end
- string
] == '=')
116 static char **last_environ
= NULL
;
117 char **new_environ
= (char **) malloc ((size
+ 2) * sizeof (char *));
118 if (new_environ
== NULL
)
120 (void) memcpy ((void *) new_environ
, (void *) environ
,
121 size
* sizeof (char *));
122 new_environ
[size
] = (char *) string
;
123 new_environ
[size
+ 1] = NULL
;
125 last_environ
= new_environ
;
126 environ
= new_environ
;