1 /* Copyright (C) 1992, 1995, 1996, 1997, 2002 Free Software Foundation, Inc.
2 This file based on setenv.c in the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 The GNU C Library 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 GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
17 Boston, MA 02110-1301, USA. */
22 @deftypefn Supplemental int setenv (const char *@var{name}, const char *@var{value}, int @var{overwrite})
23 @deftypefnx Supplemental void unsetenv (const char *@var{name})
25 @code{setenv} adds @var{name} to the environment with value
26 @var{value}. If the name was already present in the environment,
27 the new value will be stored only if @var{overwrite} is nonzero.
28 The companion @code{unsetenv} function removes @var{name} from the
29 environment. This implementation is not safe for multithreaded code.
39 #define setenv libiberty_setenv
40 #define unsetenv libiberty_unsetenv
43 #include <sys/types.h> /* For `size_t' */
44 #include <stdio.h> /* For `NULL' */
47 #if !defined(errno) && !defined(HAVE_ERRNO_DECL)
50 #define __set_errno(ev) ((errno) = (ev))
62 #define __environ environ
63 #ifndef HAVE_ENVIRON_DECL
64 extern char **environ
;
70 /* LOCK and UNLOCK are defined as no-ops. This makes the libiberty
71 * implementation MT-Unsafe. */
75 /* Below this point, it's verbatim code from the glibc-2.0 implementation */
77 /* If this variable is not a null pointer we allocated the current
79 static char **last_environ
;
83 setenv (const char *name
, const char *value
, int replace
)
85 register char **ep
= 0;
87 const size_t namelen
= strlen (name
);
88 const size_t vallen
= strlen (value
) + 1;
93 if (__environ
!= NULL
)
95 for (ep
= __environ
; *ep
!= NULL
; ++ep
)
96 if (!strncmp (*ep
, name
, namelen
) && (*ep
)[namelen
] == '=')
102 if (__environ
== NULL
|| *ep
== NULL
)
105 if (__environ
== last_environ
&& __environ
!= NULL
)
106 /* We allocated this space; we can extend it. */
107 new_environ
= (char **) realloc (last_environ
,
108 (size
+ 2) * sizeof (char *));
110 new_environ
= (char **) malloc ((size
+ 2) * sizeof (char *));
112 if (new_environ
== NULL
)
118 new_environ
[size
] = (char *) malloc (namelen
+ 1 + vallen
);
119 if (new_environ
[size
] == NULL
)
121 free ((char *) new_environ
);
122 __set_errno (ENOMEM
);
127 if (__environ
!= last_environ
)
128 memcpy ((char *) new_environ
, (char *) __environ
,
129 size
* sizeof (char *));
131 memcpy (new_environ
[size
], name
, namelen
);
132 new_environ
[size
][namelen
] = '=';
133 memcpy (&new_environ
[size
][namelen
+ 1], value
, vallen
);
135 new_environ
[size
+ 1] = NULL
;
137 last_environ
= __environ
= new_environ
;
141 size_t len
= strlen (*ep
);
142 if (len
+ 1 < namelen
+ 1 + vallen
)
144 /* The existing string is too short; malloc a new one. */
145 char *new_string
= (char *) malloc (namelen
+ 1 + vallen
);
146 if (new_string
== NULL
)
153 memcpy (*ep
, name
, namelen
);
154 (*ep
)[namelen
] = '=';
155 memcpy (&(*ep
)[namelen
+ 1], value
, vallen
);
164 unsetenv (const char *name
)
166 const size_t len
= strlen (name
);
171 for (ep
= __environ
; *ep
; ++ep
)
172 if (!strncmp (*ep
, name
, len
) && (*ep
)[len
] == '=')
174 /* Found it. Remove this pointer by moving later ones back. */
179 /* Continue the loop in case NAME appears again. */
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