1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1998 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This 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 * This 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 this library; if not, see <http://www.gnu.org/licenses/>.
19 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
20 * file for a list of people on the GLib Team. See the ChangeLog
21 * files for a list of changes. These files are distributed with
22 * GLib at ftp://ftp.gtk.org/pub/gtk/.
31 #ifdef HAVE_CRT_EXTERNS_H
32 #include <crt_externs.h> /* for _NSGetEnviron */
38 #include "glib-private.h"
40 #include "gmessages.h"
41 #include "gstrfuncs.h"
46 /* Environ array functions {{{1 */
48 g_environ_find (gchar **envp,
49 const gchar *variable)
56 len = strlen (variable);
58 for (i = 0; envp[i]; i++)
60 if (strncmp (envp[i], variable, len) == 0 &&
70 * @envp: (nullable) (array zero-terminated=1) (transfer none): an environment
71 * list (eg, as returned from g_get_environ()), or %NULL
72 * for an empty environment list
73 * @variable: the environment variable to get
75 * Returns the value of the environment variable @variable in the
76 * provided list @envp.
78 * Returns: the value of the environment variable, or %NULL if
79 * the environment variable is not set in @envp. The returned
80 * string is owned by @envp, and will be freed if @variable is
86 g_environ_getenv (gchar **envp,
87 const gchar *variable)
91 g_return_val_if_fail (variable != NULL, NULL);
93 index = g_environ_find (envp, variable);
95 return envp[index] + strlen (variable) + 1;
102 * @envp: (nullable) (array zero-terminated=1) (transfer full): an
103 * environment list that can be freed using g_strfreev() (e.g., as
104 * returned from g_get_environ()), or %NULL for an empty
106 * @variable: the environment variable to set, must not contain '='
107 * @value: the value for to set the variable to
108 * @overwrite: whether to change the variable if it already exists
110 * Sets the environment variable @variable in the provided list
113 * Returns: (array zero-terminated=1) (transfer full): the
114 * updated environment list. Free it using g_strfreev().
119 g_environ_setenv (gchar **envp,
120 const gchar *variable,
126 g_return_val_if_fail (variable != NULL, NULL);
127 g_return_val_if_fail (strchr (variable, '=') == NULL, NULL);
128 g_return_val_if_fail (value != NULL, NULL);
130 index = g_environ_find (envp, variable);
135 g_free (envp[index]);
136 envp[index] = g_strdup_printf ("%s=%s", variable, value);
143 length = envp ? g_strv_length (envp) : 0;
144 envp = g_renew (gchar *, envp, length + 2);
145 envp[length] = g_strdup_printf ("%s=%s", variable, value);
146 envp[length + 1] = NULL;
153 g_environ_unsetenv_internal (gchar **envp,
154 const gchar *variable,
160 len = strlen (variable);
162 /* Note that we remove *all* environment entries for
163 * the variable name, not just the first.
168 if (strncmp (*e, variable, len) != 0 || (*e)[len] != '=')
188 * g_environ_unsetenv:
189 * @envp: (nullable) (array zero-terminated=1) (transfer full): an environment
190 * list that can be freed using g_strfreev() (e.g., as returned from g_get_environ()),
191 * or %NULL for an empty environment list
192 * @variable: the environment variable to remove, must not contain '='
194 * Removes the environment variable @variable from the provided
197 * Returns: (array zero-terminated=1) (transfer full): the
198 * updated environment list. Free it using g_strfreev().
203 g_environ_unsetenv (gchar **envp,
204 const gchar *variable)
206 g_return_val_if_fail (variable != NULL, NULL);
207 g_return_val_if_fail (strchr (variable, '=') == NULL, NULL);
212 return g_environ_unsetenv_internal (envp, variable, TRUE);
215 /* UNIX implemention {{{1 */
220 * @variable: the environment variable to get
222 * Returns the value of an environment variable.
224 * On UNIX, the name and value are byte strings which might or might not
225 * be in some consistent character set and encoding. On Windows, they are
227 * On Windows, in case the environment variable's value contains
228 * references to other environment variables, they are expanded.
230 * Returns: the value of the environment variable, or %NULL if
231 * the environment variable is not found. The returned string
232 * may be overwritten by the next call to g_getenv(), g_setenv()
236 g_getenv (const gchar *variable)
238 g_return_val_if_fail (variable != NULL, NULL);
240 return getenv (variable);
245 * @variable: the environment variable to set, must not contain '='.
246 * @value: the value for to set the variable to.
247 * @overwrite: whether to change the variable if it already exists.
249 * Sets an environment variable. On UNIX, both the variable's name and
250 * value can be arbitrary byte strings, except that the variable's name
251 * cannot contain '='. On Windows, they should be in UTF-8.
253 * Note that on some systems, when variables are overwritten, the memory
254 * used for the previous variables and its value isn't reclaimed.
256 * You should be mindful of the fact that environment variable handling
257 * in UNIX is not thread-safe, and your program may crash if one thread
258 * calls g_setenv() while another thread is calling getenv(). (And note
259 * that many functions, such as gettext(), call getenv() internally.)
260 * This function is only safe to use at the very start of your program,
261 * before creating any other threads (or creating objects that create
262 * worker threads of their own).
264 * If you need to set up the environment for a child process, you can
265 * use g_get_environ() to get an environment array, modify that with
266 * g_environ_setenv() and g_environ_unsetenv(), and then pass that
267 * array directly to execvpe(), g_spawn_async(), or the like.
269 * Returns: %FALSE if the environment variable couldn't be set.
274 g_setenv (const gchar *variable,
283 g_return_val_if_fail (variable != NULL, FALSE);
284 g_return_val_if_fail (strchr (variable, '=') == NULL, FALSE);
285 g_return_val_if_fail (value != NULL, FALSE);
288 result = setenv (variable, value, overwrite);
290 if (!overwrite && getenv (variable) != NULL)
293 /* This results in a leak when you overwrite existing
294 * settings. It would be fairly easy to fix this by keeping
295 * our own parallel array or hash table.
297 string = g_strconcat (variable, "=", value, NULL);
298 result = putenv (string);
303 #ifdef HAVE__NSGETENVIRON
304 #define environ (*_NSGetEnviron())
306 /* According to the Single Unix Specification, environ is not
307 * in any system header, although unistd.h often declares it.
309 extern char **environ;
314 * @variable: the environment variable to remove, must not contain '='
316 * Removes an environment variable from the environment.
318 * Note that on some systems, when variables are overwritten, the
319 * memory used for the previous variables and its value isn't reclaimed.
321 * You should be mindful of the fact that environment variable handling
322 * in UNIX is not thread-safe, and your program may crash if one thread
323 * calls g_unsetenv() while another thread is calling getenv(). (And note
324 * that many functions, such as gettext(), call getenv() internally.) This
325 * function is only safe to use at the very start of your program, before
326 * creating any other threads (or creating objects that create worker
327 * threads of their own).
329 * If you need to set up the environment for a child process, you can
330 * use g_get_environ() to get an environment array, modify that with
331 * g_environ_setenv() and g_environ_unsetenv(), and then pass that
332 * array directly to execvpe(), g_spawn_async(), or the like.
337 g_unsetenv (const gchar *variable)
339 g_return_if_fail (variable != NULL);
340 g_return_if_fail (strchr (variable, '=') == NULL);
344 #else /* !HAVE_UNSETENV */
345 /* Mess directly with the environ array.
346 * This seems to be the only portable way to do this.
348 g_environ_unsetenv_internal (environ, variable, FALSE);
349 #endif /* !HAVE_UNSETENV */
355 * Gets the names of all variables set in the environment.
357 * Programs that want to be portable to Windows should typically use
358 * this function and g_getenv() instead of using the environ array
359 * from the C library directly. On Windows, the strings in the environ
360 * array are in system codepage encoding, while in most of the typical
361 * use cases for environment variables in GLib-using programs you want
362 * the UTF-8 encoding that this function and g_getenv() provide.
364 * Returns: (array zero-terminated=1) (transfer full): a %NULL-terminated
365 * list of strings which must be freed with g_strfreev().
375 len = g_strv_length (environ);
376 result = g_new0 (gchar *, len + 1);
379 for (i = 0; i < len; i++)
381 eq = strchr (environ[i], '=');
383 result[j++] = g_strndup (environ[i], eq - environ[i]);
394 * Gets the list of environment variables for the current process.
396 * The list is %NULL terminated and each item in the list is of the
399 * This is equivalent to direct access to the 'environ' global variable,
402 * The return value is freshly allocated and it should be freed with
403 * g_strfreev() when it is no longer needed.
405 * Returns: (array zero-terminated=1) (transfer full): the list of
406 * environment variables
413 return g_strdupv (environ);
416 /* Win32 implementation {{{1 */
417 #else /* G_OS_WIN32 */
420 g_getenv (const gchar *variable)
424 wchar_t dummy[2], *wname, *wvalue;
427 g_return_val_if_fail (variable != NULL, NULL);
428 g_return_val_if_fail (g_utf8_validate (variable, -1, NULL), NULL);
430 /* On Windows NT, it is relatively typical that environment
431 * variables contain references to other environment variables. If
432 * so, use ExpandEnvironmentStrings(). (In an ideal world, such
433 * environment variables would be stored in the Registry as
434 * REG_EXPAND_SZ type values, and would then get automatically
435 * expanded before a program sees them. But there is broken software
436 * that stores environment variables as REG_SZ values even if they
437 * contain references to other environment variables.)
440 wname = g_utf8_to_utf16 (variable, -1, NULL, NULL, NULL);
442 len = GetEnvironmentVariableW (wname, dummy, 2);
447 if (GetLastError () == ERROR_ENVVAR_NOT_FOUND)
450 quark = g_quark_from_static_string ("");
451 return g_quark_to_string (quark);
456 wvalue = g_new (wchar_t, len);
458 if (GetEnvironmentVariableW (wname, wvalue, len) != len - 1)
465 if (wcschr (wvalue, L'%') != NULL)
467 wchar_t *tem = wvalue;
469 len = ExpandEnvironmentStringsW (wvalue, dummy, 2);
473 wvalue = g_new (wchar_t, len);
475 if (ExpandEnvironmentStringsW (tem, wvalue, len) != len)
485 value = g_utf16_to_utf8 (wvalue, -1, NULL, NULL, NULL);
490 quark = g_quark_from_string (value);
493 return g_quark_to_string (quark);
497 g_setenv (const gchar *variable,
502 wchar_t *wname, *wvalue, *wassignment;
505 g_return_val_if_fail (variable != NULL, FALSE);
506 g_return_val_if_fail (strchr (variable, '=') == NULL, FALSE);
507 g_return_val_if_fail (value != NULL, FALSE);
508 g_return_val_if_fail (g_utf8_validate (variable, -1, NULL), FALSE);
509 g_return_val_if_fail (g_utf8_validate (value, -1, NULL), FALSE);
511 if (!overwrite && g_getenv (variable) != NULL)
514 /* We want to (if possible) set both the environment variable copy
515 * kept by the C runtime and the one kept by the system.
517 * We can't use only the C runtime's putenv or _wputenv() as that
518 * won't work for arbitrary Unicode strings in a "non-Unicode" app
519 * (with main() and not wmain()). In a "main()" app the C runtime
520 * initializes the C runtime's environment table by converting the
521 * real (wide char) environment variables to system codepage, thus
522 * breaking those that aren't representable in the system codepage.
524 * As the C runtime's putenv() will also set the system copy, we do
525 * the putenv() first, then call SetEnvironmentValueW ourselves.
528 wname = g_utf8_to_utf16 (variable, -1, NULL, NULL, NULL);
529 wvalue = g_utf8_to_utf16 (value, -1, NULL, NULL, NULL);
530 tem = g_strconcat (variable, "=", value, NULL);
531 wassignment = g_utf8_to_utf16 (tem, -1, NULL, NULL, NULL);
534 _wputenv (wassignment);
535 g_free (wassignment);
537 retval = (SetEnvironmentVariableW (wname, wvalue) != 0);
546 g_unsetenv (const gchar *variable)
548 wchar_t *wname, *wassignment;
551 g_return_if_fail (variable != NULL);
552 g_return_if_fail (strchr (variable, '=') == NULL);
553 g_return_if_fail (g_utf8_validate (variable, -1, NULL));
555 wname = g_utf8_to_utf16 (variable, -1, NULL, NULL, NULL);
556 tem = g_strconcat (variable, "=", NULL);
557 wassignment = g_utf8_to_utf16 (tem, -1, NULL, NULL, NULL);
560 _wputenv (wassignment);
561 g_free (wassignment);
563 SetEnvironmentVariableW (wname, NULL);
575 p = (wchar_t *) GetEnvironmentStringsW ();
585 result = g_new0 (gchar *, len + 1);
591 result[j] = g_utf16_to_utf8 (q, -1, NULL, NULL, NULL);
592 if (result[j] != NULL)
594 eq = strchr (result[j], '=');
595 if (eq && eq > result[j])
606 FreeEnvironmentStringsW (p);
618 strings = GetEnvironmentStringsW ();
619 for (n = 0, i = 0; strings[n]; i++)
620 n += wcslen (strings + n) + 1;
622 result = g_new (char *, i + 1);
623 for (n = 0, i = 0; strings[n]; i++)
625 result[i] = g_utf16_to_utf8 (strings + n, -1, NULL, NULL, NULL);
626 n += wcslen (strings + n) + 1;
628 FreeEnvironmentStringsW (strings);
634 #endif /* G_OS_WIN32 */
638 /* Binary compatibility versions. Not for newly compiled code. */
640 _GLIB_EXTERN const gchar *g_getenv_utf8 (const gchar *variable);
641 _GLIB_EXTERN gboolean g_setenv_utf8 (const gchar *variable,
644 _GLIB_EXTERN void g_unsetenv_utf8 (const gchar *variable);
647 g_getenv_utf8 (const gchar *variable)
649 return g_getenv (variable);
653 g_setenv_utf8 (const gchar *variable,
657 return g_setenv (variable, value, overwrite);
661 g_unsetenv_utf8 (const gchar *variable)
663 return g_unsetenv (variable);
669 /* vim: set foldmethod=marker: */