common/localename.c

   1 /* localename.c - Determine the current selected locale.
   2    Copyright (C) 1995-1999, 2000-2003, 2007,
   3                  2008 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License
   7    as published by the Free Software Foundation; either version 2.1,
   8    or (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with this program; if not, see <http://www.gnu.org/licenses/>.
  17 */
  18 /* Written by Ulrich Drepper <drepper@gnu.org>, 1995.  */
  19 /* Win32 code written by Tor Lillqvist <tml@iki.fi>.  */
  20 /* Modified for GpgOL use by Werner Koch <wk@gnupg.org>, 2005.  */
  21 /* Modified for GnuPG use by Werner Koch <wk@gnupg.org>, 2007 */
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #ifdef HAVE_LOCALE_H
  30 #include <locale.h>
  31 #endif
  32
  33 #include "../jnlib/w32help.h"
  34
  35 /* XPG3 defines the result of 'setlocale (category, NULL)' as:
  36    "Directs 'setlocale()' to query 'category' and return the current
  37     setting of 'local'."
  38    However it does not specify the exact format.  Neither do SUSV2 and
  39    ISO C 99.  So we can use this feature only on selected systems (e.g.
  40    those using GNU C Library).  */
  41 #if defined _LIBC || (defined __GNU_LIBRARY__ && __GNU_LIBRARY__ >= 2)
  42 # define HAVE_LOCALE_NULL
  43 #endif
  44
  45 /* Use a dummy value for LC_MESSAGES in case it is not defined.  This
  46    works becuase we always test for HAVE_LC_MESSAGES and the core
  47    fucntion takes the category as a string as well.  */
  48 #ifndef HAVE_LC_MESSAGES
  49 #define LC_MESSAGES 0
  50 #endif
  51
  52
  53 /* Determine the current locale's name, and canonicalize it into XPG syntax
  54      language[_territory[.codeset]][@modifier]
  55    The codeset part in the result is not reliable; the locale_charset()
  56    should be used for codeset information instead.
  57    The result must not be freed; it is statically allocated.  */
  58
  59 #ifndef HAVE_W32_SYSTEM
  60 static const char *
  61 do_nl_locale_name (int category, const char *categoryname)
  62 {
  63   const char *retval;
  64
  65   /* Use the POSIX methods of looking to 'LC_ALL', 'LC_xxx', and 'LANG'.
  66      On some systems this can be done by the 'setlocale' function itself.  */
  67 # if defined HAVE_SETLOCALE && defined HAVE_LC_MESSAGES && defined HAVE_LOCALE_NULL
  68   (void)categoryname;
  69   retval = setlocale (category, NULL);
  70 # else
  71   /* Setting of LC_ALL overwrites all other.  */
  72   retval = getenv ("LC_ALL");
  73   if (retval == NULL || retval[0] == '\0')
  74     {
  75       /* Next comes the name of the desired category.  */
  76       retval = getenv (categoryname);
  77       if (retval == NULL || retval[0] == '\0')
  78         {
  79           /* Last possibility is the LANG environment variable.  */
  80           retval = getenv ("LANG");
  81           if (retval == NULL || retval[0] == '\0')
  82             /* We use C as the default domain.  POSIX says this is
  83                implementation defined.  */
  84             retval = "C";
  85         }
  86     }
  87 # endif
  88
  89   return retval;
  90 }
  91 #endif /* HAVE_W32_SYSTEM */
  92
  93
  94
  95 /* Return the locale used for translatable messages.  The standard C
  96    and POSIX are locale names are mapped to an empty string.  If a
  97    locale can't be found an empty string will be returned.  */
  98 const char *
  99 gnupg_messages_locale_name (void)
 100 {
 101   const char *s;
 102
 103 #ifdef HAVE_W32_SYSTEM
 104   /* We use the localname function from ../jnlib/w32-gettext.c. */
 105   s = gettext_localename ();
 106 #else
 107   s = do_nl_locale_name (LC_MESSAGES, "LC_MESSAGES");
 108 #endif
 109   if (!s)
 110     s = "";
 111   else if (!strcmp (s, "C") || !strcmp (s, "POSIX"))
 112     s = "";
 113
 114   return s;
 115 }
 116