lib/hard-locale.c

   1 /* hard-locale.c -- Determine whether a locale is hard.
   2
   3    Copyright (C) 1997-1999, 2002-2004, 2006-2007, 2009-2019 Free Software
   4    Foundation, Inc.
   5
   6    This program is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #include <config.h>
  20
  21 #include "hard-locale.h"
  22
  23 #include <locale.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #ifdef __GLIBC__
  28 # define GLIBC_VERSION __GLIBC__
  29 #elif defined __UCLIBC__
  30 # define GLIBC_VERSION 2
  31 #else
  32 # define GLIBC_VERSION 0
  33 #endif
  34
  35 /* Return true if the current CATEGORY locale is hard, i.e. if you
  36    can't get away with assuming traditional C or POSIX behavior.  */
  37 bool
  38 hard_locale (int category)
  39 {
  40   bool hard = true;
  41   char const *p = setlocale (category, NULL);
  42
  43   if (p)
  44     {
  45       if (2 <= GLIBC_VERSION)
  46         {
  47           if (strcmp (p, "C") == 0 || strcmp (p, "POSIX") == 0)
  48             hard = false;
  49         }
  50       else
  51         {
  52           char *locale = strdup (p);
  53           if (locale)
  54             {
  55               /* Temporarily set the locale to the "C" and "POSIX" locales
  56                  to find their names, so that we can determine whether one
  57                  or the other is the caller's locale.  */
  58               if (((p = setlocale (category, "C"))
  59                    && strcmp (p, locale) == 0)
  60                   || ((p = setlocale (category, "POSIX"))
  61                       && strcmp (p, locale) == 0))
  62                 hard = false;
  63
  64               /* Restore the caller's locale.  */
  65               setlocale (category, locale);
  66               free (locale);
  67             }
  68         }
  69     }
  70
  71   return hard;
  72 }