locale/nl_langinfo.c

/* nl_langinfo -- User interface for extracting locale-dependent parameters.
Copyright (C) 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <langinfo.h>
#include <errno.h>
#include <stddef.h>
#include "localeinfo.h"

/* This array duplicates `_nl_current' defined in setlocale.c; but since
   the references here are not weak references, this guarantees that the
   data for all the categories will be linked in.  */

static const struct locale_data * *const nldata[] =
{
#define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  [category] = &_nl_current_##category,
#include "categories.def"
#undef	DEFINE_CATEGORY
};


/* Return a string with the data for locale-dependent parameter ITEM.  */

char *
nl_langinfo (item)
     nl_item item;
{
  int category = _NL_ITEM_CATEGORY (item);
  unsigned int index = _NL_ITEM_INDEX (item);
  const struct locale_data *data;

  if (category < 0 || category >= LC_ALL)
    {
      /* Bogus category: bogus item.  */
      errno = EINVAL;
      return NULL;
    }

  data = *nldata[category];

  if (index >= data->nstrings)
    {
      /* Bogus index for this category: bogus item.  */
      errno = EINVAL;
      return NULL;
    }

  /* Return the string for the specified item.  */
  return (char *) data->strings[index];
}