1 /* Copyright (C) 1992-2019 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}, @
23 const char *@var{value}, int @var{overwrite})
24 @deftypefnx Supplemental void unsetenv (const char *@var{name})
26 @code{setenv} adds @var{name} to the environment with value
27 @var{value}. If the name was already present in the environment,
28 the new value will be stored only if @var{overwrite} is nonzero.
29 The companion @code{unsetenv} function removes @var{name} from the
30 environment. This implementation is not safe for multithreaded code.
40 #define setenv libiberty_setenv
41 #define unsetenv libiberty_unsetenv
44 #include <sys/types.h> /* For `size_t' */
45 #include <stdio.h> /* For `NULL' */
48 #if !defined(errno) && !defined(HAVE_ERRNO_DECL)
51 #define __set_errno(ev) ((errno) = (ev))
63 #define __environ environ
69 /* LOCK and UNLOCK are defined as no-ops. This makes the libiberty
70 * implementation MT-Unsafe. */
74 /* Below this point, it's verbatim code from the glibc-2.0 implementation */
76 /* If this variable is not a null pointer we allocated the current
78 static char **last_environ
;
82 setenv (const char *name
, const char *value
, int replace
)
84 register char **ep
= 0;
86 const size_t namelen
= strlen (name
);
87 const size_t vallen
= strlen (value
) + 1;
92 if (__environ
!= NULL
)
94 for (ep
= __environ
; *ep
!= NULL
; ++ep
)
95 if (!strncmp (*ep
, name
, namelen
) && (*ep
)[namelen
] == '=')
101 if (__environ
== NULL
|| *ep
== NULL
)
104 if (__environ
== last_environ
&& __environ
!= NULL
)
105 /* We allocated this space; we can extend it. */
106 new_environ
= (char **) realloc (last_environ
,
107 (size
+ 2) * sizeof (char *));
109 new_environ
= (char **) malloc ((size
+ 2) * sizeof (char *));
111 if (new_environ
== NULL
)
117 new_environ
[size
] = (char *) malloc (namelen
+ 1 + vallen
);
118 if (new_environ
[size
] == NULL
)
120 free ((char *) new_environ
);
121 __set_errno (ENOMEM
);
126 if (__environ
!= last_environ
)
127 memcpy ((char *) new_environ
, (char *) __environ
,
128 size
* sizeof (char *));
130 memcpy (new_environ
[size
], name
, namelen
);
131 new_environ
[size
][namelen
] = '=';
132 memcpy (&new_environ
[size
][namelen
+ 1], value
, vallen
);
134 new_environ
[size
+ 1] = NULL
;
136 last_environ
= __environ
= new_environ
;
140 size_t len
= strlen (*ep
);
141 if (len
+ 1 < namelen
+ 1 + vallen
)
143 /* The existing string is too short; malloc a new one. */
144 char *new_string
= (char *) malloc (namelen
+ 1 + vallen
);
145 if (new_string
== NULL
)
152 memcpy (*ep
, name
, namelen
);
153 (*ep
)[namelen
] = '=';
154 memcpy (&(*ep
)[namelen
+ 1], value
, vallen
);
163 unsetenv (const char *name
)
165 const size_t len
= strlen (name
);
170 for (ep
= __environ
; *ep
; ++ep
)
171 if (!strncmp (*ep
, name
, len
) && (*ep
)[len
] == '=')
173 /* Found it. Remove this pointer by moving later ones back. */
178 /* Continue the loop in case NAME appears again. */
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