locale/findlocale.c

   1 /* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
   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 not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <locale.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/mman.h>
  24
  25 #include "localeinfo.h"
  26
  27
  28 /* Constant data defined in setlocale.c.  */
  29 extern struct locale_data *const _nl_C[];
  30
  31
  32 /* For each category we keep a list of records for the locale files
  33    which are somehow addressed.  */
  34 static struct loaded_l10nfile *locale_file_list[LC_ALL];
  35
  36
  37 struct locale_data *
  38 _nl_find_locale (const char *locale_path, size_t locale_path_len,
  39                  int category, const char **name)
  40 {
  41   int mask;
  42   /* Name of the locale for this category.  */
  43   char *loc_name;
  44   const char *language;
  45   const char *modifier;
  46   const char *territory;
  47   const char *codeset;
  48   const char *normalized_codeset;
  49   const char *special;
  50   const char *sponsor;
  51   const char *revision;
  52   struct loaded_l10nfile *locale_file;
  53
  54   if ((*name)[0] == '\0')
  55     {
  56       /* The user decides which locale to use by setting environment
  57          variables.  */
  58       *name = getenv ("LC_ALL");
  59       if (*name == NULL || (*name)[0] == '\0')
  60         *name = getenv (_nl_category_names[category]);
  61       if (*name == NULL || (*name)[0] == '\0')
  62         *name = getenv ("LANG");
  63       if (*name == NULL || (*name)[0] == '\0')
  64         *name = (char *) _nl_C_name;
  65     }
  66
  67   if (strcmp (*name, _nl_C_name) == 0 || strcmp (*name, "POSIX") == 0)
  68     {
  69       /* We need not load anything.  The needed data is contained in
  70          the library itself.  */
  71       *name = (char *) _nl_C_name;
  72       return _nl_C[category];
  73     }
  74
  75   /* We really have to load some data.  First see whether the name is
  76      an alias.  Please note that this makes it impossible to have "C"
  77      or "POSIX" as aliases.  */
  78   loc_name = (char *) _nl_expand_alias (*name);
  79   if (loc_name == NULL)
  80     /* It is no alias.  */
  81     loc_name = (char *) *name;
  82
  83   /* Make a writable copy of the locale name.  */
  84   loc_name = __strdup (loc_name);
  85
  86   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
  87
  88                 language[_territory[.codeset]][@modifier]
  89
  90      and six parts for the CEN syntax:
  91
  92         language[_territory][+audience][+special][,[sponsor][_revision]]
  93
  94      Beside the first all of them are allowed to be missing.  If the
  95      full specified locale is not found, the less specific one are
  96      looked for.  The various part will be stripped of according to
  97      the following order:
  98                 (1) revision
  99                 (2) sponsor
 100                 (3) special
 101                 (4) codeset
 102                 (5) normalized codeset
 103                 (6) territory
 104                 (7) audience/modifier
 105    */
 106   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 107                            &codeset, &normalized_codeset, &special,
 108                            &sponsor, &revision);
 109
 110   /* If exactly this locale was already asked for we have an entry with
 111      the complete name.  */
 112   locale_file = _nl_make_l10nflist (&locale_file_list[category],
 113                                     locale_path, locale_path_len, mask,
 114                                     language, territory, codeset,
 115                                     normalized_codeset, modifier, special,
 116                                     sponsor, revision,
 117                                     _nl_category_names[category], 0);
 118
 119   if (locale_file == NULL)
 120     {
 121       /* Find status record for addressed locale file.  We have to search
 122          through all directories in the locale path.  */
 123       locale_file = _nl_make_l10nflist (&locale_file_list[category],
 124                                         locale_path, locale_path_len, mask,
 125                                         language, territory, codeset,
 126                                         normalized_codeset, modifier, special,
 127                                         sponsor, revision,
 128                                         _nl_category_names[category], 1);
 129       if (locale_file == NULL)
 130         /* This means we are out of core.  */
 131         return NULL;
 132     }
 133   else
 134     /* If the addressed locale is already available it should be
 135        freed.  If we would not do this switching back and force
 136        between two locales would slowly eat up all memory.  */
 137     free ((void *) loc_name);
 138
 139   if (locale_file->decided == 0)
 140     _nl_load_locale (locale_file, category);
 141
 142   if (locale_file->data == NULL)
 143     {
 144       int cnt;
 145       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 146         {
 147           if (locale_file->successor[cnt]->decided == 0)
 148             _nl_load_locale (locale_file->successor[cnt], category);
 149           if (locale_file->successor[cnt]->data != NULL)
 150             break;
 151         }
 152       /* Move the entry we found (or NULL) to the first place of
 153          successors.  */
 154       locale_file->successor[0] = locale_file->successor[cnt];
 155       locale_file = locale_file->successor[cnt];
 156     }
 157
 158   if (locale_file == NULL)
 159     return NULL;
 160
 161   /* Determine the locale name for which loading succeeded.  This
 162      information comes from the file name.  The form is
 163      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 164   if (((struct locale_data *) locale_file->data)->name == NULL)
 165     {
 166       char *cp, *endp;
 167
 168       endp = strrchr (locale_file->filename, '/');
 169       cp = endp - 1;
 170       while (cp[-1] != '/')
 171         --cp;
 172       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 173                                                                     endp - cp);
 174     }
 175   *name = (char *) ((struct locale_data *) locale_file->data)->name;
 176
 177   /* Increment the usage count.  */
 178   if (((struct locale_data *) locale_file->data)->usage_count
 179       != MAX_USAGE_COUNT)
 180     ++((struct locale_data *) locale_file->data)->usage_count;
 181
 182   return (struct locale_data *) locale_file->data;
 183 }
 184
 185
 186 /* Calling this function assumes the lock for handling global locale data
 187    is acquired.  */
 188 void
 189 _nl_remove_locale (int locale, struct locale_data *data)
 190 {
 191   if (--data->usage_count == 0)
 192     {
 193       /* First search the entry in the list of loaded files.  */
 194       struct loaded_l10nfile *ptr = locale_file_list[locale];
 195
 196       /* Search for the entry.  It must be in the list.  Otherwise it
 197          is a bug and we crash badly.  */
 198       while ((struct locale_data *) ptr->data != data)
 199         ptr = ptr->next;
 200
 201       /* Mark the data as not available anymore.  So when the data has
 202          to be used again it is reloaded.  */
 203       ptr->decided = 0;
 204       ptr->data = NULL;
 205
 206       /* Really delete the data.  First delete the real data.  */
 207       if (data->mmaped)
 208         {
 209           /* Try to unmap the area.  If this fails we mark the area as
 210              permanent.  */
 211           if (__munmap ((caddr_t) data->filedata, data->filesize) != 0)
 212             {
 213               data->usage_count = MAX_USAGE_COUNT;
 214               return;
 215             }
 216         }
 217       else
 218         /* The memory was malloced.  */
 219         free ((void *) data->filedata);
 220
 221       /* Now free the structure itself.  */
 222       free (data);
 223     }
 224 }