intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
   3    Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22
  23 #include <ctype.h>
  24 #include <stdio.h>
  25 #include <sys/types.h>
  26
  27 #ifdef __GNUC__
  28 # define alloca __builtin_alloca
  29 # define HAVE_ALLOCA 1
  30 #else
  31 # if defined HAVE_ALLOCA_H || defined _LIBC
  32 #  include <alloca.h>
  33 # else
  34 #  ifdef _AIX
  35  #pragma alloca
  36 #  else
  37 #   ifndef alloca
  38 char *alloca ();
  39 #   endif
  40 #  endif
  41 # endif
  42 #endif
  43
  44 #if defined STDC_HEADERS || defined _LIBC
  45 # include <stdlib.h>
  46 #else
  47 char *getenv ();
  48 # ifdef HAVE_MALLOC_H
  49 #  include <malloc.h>
  50 # else
  51 void free ();
  52 # endif
  53 #endif
  54
  55 #if defined HAVE_STRING_H || defined _LIBC
  56 # ifndef _GNU_SOURCE
  57 #  define _GNU_SOURCE   1
  58 # endif
  59 # include <string.h>
  60 #else
  61 # include <strings.h>
  62 # ifndef memcpy
  63 #  define memcpy(Dst, Src, Num) bcopy (Src, Dst, Num)
  64 # endif
  65 #endif
  66 #if !HAVE_STRCHR && !defined _LIBC
  67 # ifndef strchr
  68 #  define strchr index
  69 # endif
  70 #endif
  71
  72 #include "gettext.h"
  73 #include "gettextP.h"
  74
  75 /* @@ end of prolog @@ */
  76
  77 #ifdef _LIBC
  78 /* Rename the non ANSI C functions.  This is required by the standard
  79    because some ANSI C functions will require linking with this object
  80    file and the name space must not be polluted.  */
  81 # define strcasecmp __strcasecmp
  82
  83 # define mempcpy __mempcpy
  84 # define HAVE_MEMPCPY   1
  85
  86 /* We need locking here since we can be called from different places.  */
  87 # include <bits/libc-lock.h>
  88
  89 __libc_lock_define_initialized (static, lock);
  90 #endif
  91
  92
  93 /* For those loosing systems which don't have `alloca' we have to add
  94    some additional code emulating it.  */
  95 #ifdef HAVE_ALLOCA
  96 /* Nothing has to be done.  */
  97 # define ADD_BLOCK(list, address) /* nothing */
  98 # define FREE_BLOCKS(list) /* nothing */
  99 #else
 100 struct block_list
 101 {
 102   void *address;
 103   struct block_list *next;
 104 };
 105 # define ADD_BLOCK(list, addr)                                                \
 106   do {                                                                        \
 107     struct block_list *newp = (struct block_list *) malloc (sizeof (*newp));  \
 108     /* If we cannot get a free block we cannot add the new element to         \
 109        the list.  */                                                          \
 110     if (newp != NULL) {                                                       \
 111       newp->address = (addr);                                                 \
 112       newp->next = (list);                                                    \
 113       (list) = newp;                                                          \
 114     }                                                                         \
 115   } while (0)
 116 # define FREE_BLOCKS(list)                                                    \
 117   do {                                                                        \
 118     while (list != NULL) {                                                    \
 119       struct block_list *old = list;                                          \
 120       list = list->next;                                                      \
 121       free (old);                                                             \
 122     }                                                                         \
 123   } while (0)
 124 # undef alloca
 125 # define alloca(size) (malloc (size))
 126 #endif  /* have alloca */
 127
 128
 129 struct alias_map
 130 {
 131   const char *alias;
 132   const char *value;
 133 };
 134
 135
 136 static char *string_space = NULL;
 137 static size_t string_space_act = 0;
 138 static size_t string_space_max = 0;
 139 static struct alias_map *map;
 140 static size_t nmap = 0;
 141 static size_t maxmap = 0;
 142
 143
 144 /* Prototypes for local functions.  */
 145 static size_t read_alias_file PARAMS ((const char *fname, int fname_len))
 146      internal_function;
 147 static void extend_alias_table PARAMS ((void));
 148 static int alias_compare PARAMS ((const struct alias_map *map1,
 149                                   const struct alias_map *map2));
 150
 151
 152 const char *
 153 _nl_expand_alias (name)
 154     const char *name;
 155 {
 156   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 157   struct alias_map *retval;
 158   const char *result = NULL;
 159   size_t added;
 160
 161 #ifdef _LIBC
 162   __libc_lock_lock (lock);
 163 #endif
 164
 165   do
 166     {
 167       struct alias_map item;
 168
 169       item.alias = name;
 170
 171       if (nmap > 0)
 172         retval = (struct alias_map *) bsearch (&item, map, nmap,
 173                                                sizeof (struct alias_map),
 174                                                (int (*) PARAMS ((const void *,
 175                                                                  const void *))
 176                                                 ) alias_compare);
 177       else
 178         retval = NULL;
 179
 180       /* We really found an alias.  Return the value.  */
 181       if (retval != NULL)
 182         {
 183           result = retval->value;
 184           break;
 185         }
 186
 187       /* Perhaps we can find another alias file.  */
 188       added = 0;
 189       while (added == 0 && locale_alias_path[0] != '\0')
 190         {
 191           const char *start;
 192
 193           while (locale_alias_path[0] == ':')
 194             ++locale_alias_path;
 195           start = locale_alias_path;
 196
 197           while (locale_alias_path[0] != '\0' && locale_alias_path[0] != ':')
 198             ++locale_alias_path;
 199
 200           if (start < locale_alias_path)
 201             added = read_alias_file (start, locale_alias_path - start);
 202         }
 203     }
 204   while (added != 0);
 205
 206 #ifdef _LIBC
 207   __libc_lock_unlock (lock);
 208 #endif
 209
 210   return result;
 211 }
 212
 213
 214 static size_t
 215 internal_function
 216 read_alias_file (fname, fname_len)
 217      const char *fname;
 218      int fname_len;
 219 {
 220 #ifndef HAVE_ALLOCA
 221   struct block_list *block_list = NULL;
 222 #endif
 223   FILE *fp;
 224   char *full_fname;
 225   size_t added;
 226   static const char aliasfile[] = "/locale.alias";
 227
 228   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 229   ADD_BLOCK (block_list, full_fname);
 230 #ifdef HAVE_MEMPCPY
 231   mempcpy (mempcpy (full_fname, fname, fname_len),
 232            aliasfile, sizeof aliasfile);
 233 #else
 234   memcpy (full_fname, fname, fname_len);
 235   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 236 #endif
 237
 238   fp = fopen (full_fname, "r");
 239   if (fp == NULL)
 240     {
 241       FREE_BLOCKS (block_list);
 242       return 0;
 243     }
 244
 245   added = 0;
 246   while (!feof (fp))
 247     {
 248       /* It is a reasonable approach to use a fix buffer here because
 249          a) we are only interested in the first two fields
 250          b) these fields must be usable as file names and so must not
 251             be that long
 252        */
 253       unsigned char buf[BUFSIZ];
 254       unsigned char *alias;
 255       unsigned char *value;
 256       unsigned char *cp;
 257
 258       if (fgets (buf, sizeof buf, fp) == NULL)
 259         /* EOF reached.  */
 260         break;
 261
 262       /* Possibly not the whole line fits into the buffer.  Ignore
 263          the rest of the line.  */
 264       if (strchr (buf, '\n') == NULL)
 265         {
 266           char altbuf[BUFSIZ];
 267           do
 268             if (fgets (altbuf, sizeof altbuf, fp) == NULL)
 269               /* Make sure the inner loop will be left.  The outer loop
 270                  will exit at the `feof' test.  */
 271               break;
 272           while (strchr (altbuf, '\n') == NULL);
 273         }
 274
 275       cp = buf;
 276       /* Ignore leading white space.  */
 277       while (isspace (cp[0]))
 278         ++cp;
 279
 280       /* A leading '#' signals a comment line.  */
 281       if (cp[0] != '\0' && cp[0] != '#')
 282         {
 283           alias = cp++;
 284           while (cp[0] != '\0' && !isspace (cp[0]))
 285             ++cp;
 286           /* Terminate alias name.  */
 287           if (cp[0] != '\0')
 288             *cp++ = '\0';
 289
 290           /* Now look for the beginning of the value.  */
 291           while (isspace (cp[0]))
 292             ++cp;
 293
 294           if (cp[0] != '\0')
 295             {
 296               size_t alias_len;
 297               size_t value_len;
 298
 299               value = cp++;
 300               while (cp[0] != '\0' && !isspace (cp[0]))
 301                 ++cp;
 302               /* Terminate value.  */
 303               if (cp[0] == '\n')
 304                 {
 305                   /* This has to be done to make the following test
 306                      for the end of line possible.  We are looking for
 307                      the terminating '\n' which do not overwrite here.  */
 308                   *cp++ = '\0';
 309                   *cp = '\n';
 310                 }
 311               else if (cp[0] != '\0')
 312                 *cp++ = '\0';
 313
 314               if (nmap >= maxmap)
 315                 extend_alias_table ();
 316
 317               alias_len = strlen (alias) + 1;
 318               value_len = strlen (value) + 1;
 319
 320               if (string_space_act + alias_len + value_len > string_space_max)
 321                 {
 322                   /* Increase size of memory pool.  */
 323                   size_t new_size = (string_space_max
 324                                      + (alias_len + value_len > 1024
 325                                         ? alias_len + value_len : 1024));
 326                   char *new_pool = (char *) realloc (string_space, new_size);
 327                   if (new_pool == NULL)
 328                     {
 329                       FREE_BLOCKS (block_list);
 330                       return added;
 331                     }
 332                   string_space = new_pool;
 333                   string_space_max = new_size;
 334                 }
 335
 336               map[nmap].alias = memcpy (&string_space[string_space_act],
 337                                         alias, alias_len);
 338               string_space_act += alias_len;
 339
 340               map[nmap].value = memcpy (&string_space[string_space_act],
 341                                         value, value_len);
 342               string_space_act += value_len;
 343
 344               ++nmap;
 345               ++added;
 346             }
 347         }
 348     }
 349
 350   /* Should we test for ferror()?  I think we have to silently ignore
 351      errors.  --drepper  */
 352   fclose (fp);
 353
 354   if (added > 0)
 355     qsort (map, nmap, sizeof (struct alias_map),
 356            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 357
 358   FREE_BLOCKS (block_list);
 359   return added;
 360 }
 361
 362
 363 static void
 364 extend_alias_table ()
 365 {
 366   size_t new_size;
 367   struct alias_map *new_map;
 368
 369   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 370   new_map = (struct alias_map *) realloc (map, (new_size
 371                                                 * sizeof (struct alias_map)));
 372   if (new_map == NULL)
 373     /* Simply don't extend: we don't have any more core.  */
 374     return;
 375
 376   map = new_map;
 377   maxmap = new_size;
 378 }
 379
 380
 381 #ifdef _LIBC
 382 static void __attribute__ ((unused))
 383 free_mem (void)
 384 {
 385   if (string_space != NULL)
 386     free (string_space);
 387   if (map != NULL)
 388     free (map);
 389 }
 390 text_set_element (__libc_subfreeres, free_mem);
 391 #endif
 392
 393
 394 static int
 395 alias_compare (map1, map2)
 396      const struct alias_map *map1;
 397      const struct alias_map *map2;
 398 {
 399 #if defined _LIBC || defined HAVE_STRCASECMP
 400   return strcasecmp (map1->alias, map2->alias);
 401 #else
 402   const unsigned char *p1 = (const unsigned char *) map1->alias;
 403   const unsigned char *p2 = (const unsigned char *) map2->alias;
 404   unsigned char c1, c2;
 405
 406   if (p1 == p2)
 407     return 0;
 408
 409   do
 410     {
 411       /* I know this seems to be odd but the tolower() function in
 412          some systems libc cannot handle nonalpha characters.  */
 413       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 414       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 415       if (c1 == '\0')
 416         break;
 417       ++p1;
 418       ++p2;
 419     }
 420   while (c1 == c2);
 421
 422   return c1 - c2;
 423 #endif
 424 }