locale/nl_langinfo.c

   1 /* nl_langinfo -- User interface for extracting locale-dependent parameters.
   2 Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   3 This file is part of the GNU C Library.
   4
   5 The GNU C Library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 License, or (at your option) any later version.
   9
  10 The GNU C Library 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 Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #include <langinfo.h>
  21 #include <errno.h>
  22 #include <stddef.h>
  23 #include "localeinfo.h"
  24
  25 /* This array duplicates `_nl_current' defined in setlocale.c; but since
  26    the references here are not weak references, this guarantees that the
  27    data for all the categories will be linked in.  */
  28
  29 static const struct locale_data * *const nldata[] =
  30 {
  31 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  32   [category] = &_nl_current_##category,
  33 #include "categories.def"
  34 #undef  DEFINE_CATEGORY
  35 };
  36
  37
  38 /* Return a string with the data for locale-dependent parameter ITEM.  */
  39
  40 char *
  41 nl_langinfo (item)
  42      nl_item item;
  43 {
  44   int category = _NL_ITEM_CATEGORY (item);
  45   unsigned int index = _NL_ITEM_INDEX (item);
  46   const struct locale_data *data;
  47
  48   if (category < 0 || category >= LC_ALL)
  49     {
  50       /* Bogus category: bogus item.  */
  51       errno = EINVAL;
  52       return NULL;
  53     }
  54
  55   data = *nldata[category];
  56
  57   if (index >= data->nstrings)
  58     {
  59       /* Bogus index for this category: bogus item.  */
  60       errno = EINVAL;
  61       return NULL;
  62     }
  63
  64   /* Return the string for the specified item.  */
  65   return (char *) data->values[index].string;
  66 }