#include <stdio.h>
#include <string.h>
#include <locale.h>
#include <locale/localeinfo.h>
#include <locale/elem-hash.h>
#include <locale/coll-lookup.h>

int
main (void)
{
  int32_t table_size, hash, elem, second, idx = 0;
  const int32_t *symb_table;
  const unsigned char *extra, *collseqmb, *collseqwc;
  const unsigned char *elem_aa = "a-a";
  char *cur_locale;

  cur_locale = setlocale (LC_ALL, "da_DK.ISO-8859-1");
  if (cur_locale == NULL)
    {
      printf ("cannot set locale: %m\n");
      return 1;
    }
  printf ("current locale : %s\n", cur_locale);
  if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) == 0)
    {
      printf("No rule\n");
      return 1;
    }

  /* Lookup collation sequences for 'a'.  */
  collseqmb = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
  collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
  printf ("multibyte collation sequence for 'a': %d\n", collseqmb['a']);
  printf ("wide char collation sequence for 'a': %d\n",
          collseq_table_lookup (collseqwc, L'a'));

  /* Find index for 'a-a'.  */
  table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
  symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
                                              _NL_COLLATE_SYMB_TABLEMB);
  extra = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
  hash = elem_hash(elem_aa, strlen(elem_aa));
  elem = hash % table_size;
  second = hash % (table_size - 2);
  while (symb_table[2 * elem] != 0)
    {
      if (symb_table[2 * elem] == hash
          && strlen(elem_aa) == extra[symb_table[2 * elem + 1]]
          && memcmp (elem_aa, &extra[symb_table[2 * elem + 1] + 1],
                     strlen(elem_aa)) == 0)
        {
          idx = symb_table[2 * elem + 1];
          break;
        }
      elem += second;
    }
  if (idx == 0)
    {
      printf("Not found %s.", elem_aa);
      return 1;
    }

  /* Lookup collation sequences for 'a-a'.  */
  idx += extra[idx] + 1;
  idx += extra[idx] + 1;
  idx = (idx + 3) & ~3;
  printf ("multibyte collation sequence for 'a-a': %d\n",
          *(uint32_t*)(extra + idx));
  idx += sizeof(uint32_t);
  idx += sizeof(uint32_t) * (1 + *(uint32_t*)(extra + idx));
  printf ("wide char collation sequence for 'a-a': %d\n",
          *(uint32_t*)(extra + idx));

  return 0;
}