1 /* Copyright (C) 1992,1995-2001,2004 Free Software Foundation, Inc.
2 This file is part of 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 Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the 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 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 /* Fixme: Why do we need to include the assuan header and why the
26 #include "assuan-defs.h"
27 #endif /*HAVE_ASSUAN_H*/
29 #define __builtin_expect(cond,val) (cond)
33 # if !defined errno && !defined HAVE_ERRNO_DECL
36 # define __set_errno(ev) ((errno) = (ev))
39 #if _LIBC || HAVE_STDLIB_H
42 #if _LIBC || HAVE_STRING_H
45 #if _LIBC || HAVE_UNISTD_H
50 # define __environ environ
51 # ifndef HAVE_ENVIRON_DECL
52 extern char **environ;
57 /* This lock protects against simultaneous modifications of `environ'. */
58 # include <bits/libc-lock.h>
59 __libc_lock_define_initialized (static, envlock)
60 # define LOCK __libc_lock_lock (envlock)
61 # define UNLOCK __libc_lock_unlock (envlock)
67 /* In the GNU C library we must keep the namespace clean. */
69 # define setenv __setenv
70 # define unsetenv __unsetenv
71 # define clearenv __clearenv
72 # define tfind __tfind
73 # define tsearch __tsearch
76 /* In the GNU C library implementation we try to be more clever and
77 allow arbitrarily many changes of the environment given that the used
78 values are from a small set. Outside glibc this will eat up all
79 memory after a while. */
80 #if defined _LIBC || (defined HAVE_SEARCH_H && defined HAVE_TSEARCH \
82 # define USE_TSEARCH 1
85 /* This is a pointer to the root of the search tree with the known
87 static void *known_values;
89 # define KNOWN_VALUE(Str) \
91 void *value = tfind (Str, &known_values, (__compar_fn_t) strcmp); \
92 value != NULL ? *(char **) value : NULL; \
94 # define STORE_VALUE(Str) \
95 tsearch (Str, &known_values, (__compar_fn_t) strcmp)
100 # define KNOWN_VALUE(Str) NULL
101 # define STORE_VALUE(Str) do { } while (0)
106 /* If this variable is not a null pointer we allocated the current
108 static char **last_environ;
111 /* This function is used by `setenv' and `putenv'. The difference between
112 the two functions is that for the former must create a new string which
113 is then placed in the environment, while the argument of `putenv'
114 must be used directly. This is all complicated by the fact that we try
115 to reuse values once generated for a `setenv' call since we can never
118 __add_to_environ (const char *name, const char *value, const char *combined,
122 register size_t size;
123 const size_t namelen = strlen (name);
124 const size_t vallen = value != NULL ? strlen (value) + 1 : 0;
128 /* We have to get the pointer now that we have the lock and not earlier
129 since another thread might have created a new environment. */
135 for (; *ep != NULL; ++ep)
136 if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
142 if (ep == NULL || __builtin_expect (*ep == NULL, 1))
146 /* We allocated this space; we can extend it. */
147 new_environ = (char **) realloc (last_environ,
148 (size + 2) * sizeof (char *));
149 if (new_environ == NULL)
155 /* If the whole entry is given add it. */
156 if (combined != NULL)
157 /* We must not add the string to the search tree since it belongs
159 new_environ[size] = (char *) combined;
162 /* See whether the value is already known. */
165 char new_value[namelen + 1 + vallen];
167 char *new_value = (char *) alloca (namelen + 1 + vallen);
170 __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
173 memcpy (new_value, name, namelen);
174 new_value[namelen] = '=';
175 memcpy (&new_value[namelen + 1], value, vallen);
178 new_environ[size] = KNOWN_VALUE (new_value);
179 if (__builtin_expect (new_environ[size] == NULL, 1))
182 new_environ[size] = (char *) malloc (namelen + 1 + vallen);
183 if (__builtin_expect (new_environ[size] == NULL, 0))
185 __set_errno (ENOMEM);
191 memcpy (new_environ[size], new_value, namelen + 1 + vallen);
193 memcpy (new_environ[size], name, namelen);
194 new_environ[size][namelen] = '=';
195 memcpy (&new_environ[size][namelen + 1], value, vallen);
197 /* And save the value now. We cannot do this when we remove
198 the string since then we cannot decide whether it is a
199 user string or not. */
200 STORE_VALUE (new_environ[size]);
204 if (__environ != last_environ)
205 memcpy ((char *) new_environ, (char *) __environ,
206 size * sizeof (char *));
208 new_environ[size + 1] = NULL;
210 last_environ = __environ = new_environ;
216 /* Use the user string if given. */
217 if (combined != NULL)
218 np = (char *) combined;
223 char new_value[namelen + 1 + vallen];
225 char *new_value = (char *) alloca (namelen + 1 + vallen);
228 __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
231 memcpy (new_value, name, namelen);
232 new_value[namelen] = '=';
233 memcpy (&new_value[namelen + 1], value, vallen);
236 np = KNOWN_VALUE (new_value);
237 if (__builtin_expect (np == NULL, 1))
240 np = malloc (namelen + 1 + vallen);
241 if (__builtin_expect (np == NULL, 0))
248 memcpy (np, new_value, namelen + 1 + vallen);
250 memcpy (np, name, namelen);
252 memcpy (&np[namelen + 1], value, vallen);
254 /* And remember the value. */
268 setenv (const char *name, const char *value, int replace)
270 if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
272 __set_errno (EINVAL);
276 return __add_to_environ (name, value, NULL, replace);
280 unsetenv (const char *name)
285 if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
287 __set_errno (EINVAL);
297 if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
299 /* Found it. Remove this pointer by moving later ones back. */
305 /* Continue the loop in case NAME appears again. */
315 /* The `clearenv' was planned to be added to POSIX.1 but probably
316 never made it. Nevertheless the POSIX.9 standard (POSIX bindings
317 for Fortran 77) requires this function. */
323 if (__environ == last_environ && __environ != NULL)
325 /* We allocated this environment so we can free it. */
330 /* Clear the environment pointer removes the whole environment. */
338 libc_freeres_fn (free_mem)
340 /* Remove all traces. */
343 /* Now remove the search tree. */
344 __tdestroy (known_values, free);
351 weak_alias (__setenv, setenv)
352 weak_alias (__unsetenv, unsetenv)
353 weak_alias (__clearenv, clearenv)