intl/localealias.c

   1 /* localealias.c -- handle aliases for locale names
   2    Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   3
   4 This file is part of the GNU C Library.  Its master source is NOT part of
   5 the C library, however.  The master source lives in /gd/gnu/lib.
   6
   7 The GNU C Library is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public License as
   9 published by the Free Software Foundation; either version 2 of the
  10 License, or (at your option) any later version.
  11
  12 The GNU C Library is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with the GNU C Library; see the file COPYING.LIB.  If
  19 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20 Cambridge, MA 02139, USA.  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <ctype.h>
  27 #include <stdio.h>
  28 #include <sys/types.h>
  29
  30 #ifdef __GNUC__
  31 # define alloca __builtin_alloca
  32 # define HAVE_ALLOCA 1
  33 #else
  34 # if defined HAVE_ALLOCA_H || defined _LIBC
  35 #  include <alloca.h>
  36 # else
  37 #  ifdef _AIX
  38  #pragma alloca
  39 #  else
  40 #   ifndef alloca
  41 char *alloca ();
  42 #   endif
  43 #  endif
  44 # endif
  45 #endif
  46
  47 #if defined STDC_HEADERS || defined _LIBC
  48 # include <stdlib.h>
  49 #else
  50 char *getenv ();
  51 # ifdef HAVE_MALLOC_H
  52 #  include <malloc.h>
  53 # else
  54 void free ();
  55 # endif
  56 #endif
  57
  58 #if defined HAVE_STRING_H || defined _LIBC
  59 # ifndef _GNU_SOURCE
  60 #  define _GNU_SOURCE   1
  61 # endif
  62 # include <string.h>
  63 #else
  64 # include <strings.h>
  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 #endif
  83
  84
  85 /* For those loosing systems which don't have `alloca' we have to add
  86    some additional code emulating it.  */
  87 #ifdef HAVE_ALLOCA
  88 /* Nothing has to be done.  */
  89 # define ADD_BLOCK(list, address) /* nothing */
  90 # define FREE_BLOCKS(list) /* nothing */
  91 #else
  92 struct block_list
  93 {
  94   void *address;
  95   struct block_list *next;
  96 };
  97 # define ADD_BLOCK(list, addr)                                                \
  98   do {                                                                        \
  99     struct block_list *newp = (struct block_list *) malloc (sizeof (*newp));  \
 100     /* If we cannot get a free block we cannot add the new element to         \
 101        the list.  */                                                          \
 102     if (newp != NULL) {                                                       \
 103       newp->address = (addr);                                                 \
 104       newp->next = (list);                                                    \
 105       (list) = newp;                                                          \
 106     }                                                                         \
 107   } while (0)
 108 # define FREE_BLOCKS(list)                                                    \
 109   do {                                                                        \
 110     while (list != NULL) {                                                    \
 111       struct block_list *old = list;                                          \
 112       list = list->next;                                                      \
 113       free (old);                                                             \
 114     }                                                                         \
 115   } while (0)
 116 # undef alloca
 117 # define alloca(size) (malloc (size))
 118 #endif  /* have alloca */
 119
 120
 121 struct alias_map
 122 {
 123   const char *alias;
 124   const char *value;
 125 };
 126
 127
 128 static struct alias_map *map;
 129 static size_t nmap = 0;
 130 static size_t maxmap = 0;
 131
 132
 133 /* Prototypes for local functions.  */
 134 static size_t read_alias_file PARAMS ((const char *fname, int fname_len));
 135 static void extend_alias_table PARAMS ((void));
 136 static int alias_compare PARAMS ((const struct alias_map *map1,
 137                                   const struct alias_map *map2));
 138
 139
 140 const char *
 141 _nl_expand_alias (name)
 142     const char *name;
 143 {
 144   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 145   struct alias_map *retval;
 146   size_t added;
 147
 148   do
 149     {
 150       struct alias_map item;
 151
 152       item.alias = name;
 153
 154       if (nmap > 0)
 155         retval = (struct alias_map *) bsearch (&item, map, nmap,
 156                                                sizeof (struct alias_map),
 157                                                (int (*) PARAMS ((const void *,
 158                                                                  const void *))
 159                                                 ) alias_compare);
 160       else
 161         retval = NULL;
 162
 163       /* We really found an alias.  Return the value.  */
 164       if (retval != NULL)
 165         return retval->value;
 166
 167       /* Perhaps we can find another alias file.  */
 168       added = 0;
 169       while (added == 0 && locale_alias_path[0] != '\0')
 170         {
 171           const char *start;
 172
 173           while (locale_alias_path[0] == ':')
 174             ++locale_alias_path;
 175           start = locale_alias_path;
 176
 177           while (locale_alias_path[0] != '\0' && locale_alias_path[0] != ':')
 178             ++locale_alias_path;
 179
 180           if (start < locale_alias_path)
 181             added = read_alias_file (start, locale_alias_path - start);
 182         }
 183     }
 184   while (added != 0);
 185
 186   return NULL;
 187 }
 188
 189
 190 static size_t
 191 read_alias_file (fname, fname_len)
 192      const char *fname;
 193      int fname_len;
 194 {
 195 #ifndef HAVE_ALLOCA
 196   struct block_list *block_list = NULL;
 197 #endif
 198   FILE *fp;
 199   char *full_fname;
 200   size_t added;
 201   static const char aliasfile[] = "/locale.alias";
 202
 203   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 204   ADD_BLOCK (block_list, full_fname);
 205   memcpy (full_fname, fname, fname_len);
 206   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 207
 208   fp = fopen (full_fname, "r");
 209   if (fp == NULL)
 210     {
 211       FREE_BLOCKS (block_list);
 212       return 0;
 213     }
 214
 215   added = 0;
 216   while (!feof (fp))
 217     {
 218       /* It is a reasonable approach to use a fix buffer here because
 219          a) we are only interested in the first two fields
 220          b) these fields must be usable as file names and so must not
 221             be that long
 222        */
 223       char buf[BUFSIZ];
 224       char *alias;
 225       char *value;
 226       char *cp;
 227
 228       if (fgets (buf, BUFSIZ, fp) == NULL)
 229         /* EOF reached.  */
 230         break;
 231
 232       cp = buf;
 233       /* Ignore leading white space.  */
 234       while (isspace (cp[0]))
 235         ++cp;
 236
 237       /* A leading '#' signals a comment line.  */
 238       if (cp[0] != '\0' && cp[0] != '#')
 239         {
 240           alias = cp++;
 241           while (cp[0] != '\0' && !isspace (cp[0]))
 242             ++cp;
 243           /* Terminate alias name.  */
 244           if (cp[0] != '\0')
 245             *cp++ = '\0';
 246
 247           /* Now look for the beginning of the value.  */
 248           while (isspace (cp[0]))
 249             ++cp;
 250
 251           if (cp[0] != '\0')
 252             {
 253               char *tp;
 254               size_t len;
 255
 256               value = cp++;
 257               while (cp[0] != '\0' && !isspace (cp[0]))
 258                 ++cp;
 259               /* Terminate value.  */
 260               if (cp[0] == '\n')
 261                 {
 262                   /* This has to be done to make the following test
 263                      for the end of line possible.  We are looking for
 264                      the terminating '\n' which do not overwrite here.  */
 265                   *cp++ = '\0';
 266                   *cp = '\n';
 267                 }
 268               else if (cp[0] != '\0')
 269                 *cp++ = '\0';
 270
 271               if (nmap >= maxmap)
 272                 extend_alias_table ();
 273
 274               /* We cannot depend on strdup available in the libc.  Sigh!  */
 275               len = strlen (alias) + 1;
 276               tp = (char *) malloc (len);
 277               if (tp == NULL)
 278                 {
 279                   FREE_BLOCKS (block_list);
 280                   return added;
 281                 }
 282               memcpy (tp, alias, len);
 283               map[nmap].alias = tp;
 284
 285               len = strlen (value) + 1;
 286               tp = (char *) malloc (len);
 287               if (tp == NULL)
 288                 {
 289                   FREE_BLOCKS (block_list);
 290                   return added;
 291                 }
 292               memcpy (tp, value, len);
 293               map[nmap].value = tp;
 294
 295               ++nmap;
 296               ++added;
 297             }
 298         }
 299
 300       /* Possibily not the whole line fitted into the buffer.  Ignore
 301          the rest of the line.  */
 302       while (strchr (cp, '\n') == NULL)
 303         {
 304           cp = buf;
 305           if (fgets (buf, BUFSIZ, fp) == NULL)
 306             /* Make sure the inner loop will be left.  The outer loop
 307                will exit at the `feof' test.  */
 308             *cp = '\n';
 309         }
 310     }
 311
 312   /* Should we test for ferror()?  I think we have to silently ignore
 313      errors.  --drepper  */
 314   fclose (fp);
 315
 316   if (added > 0)
 317     qsort (map, nmap, sizeof (struct alias_map),
 318            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 319
 320   FREE_BLOCKS (block_list);
 321   return added;
 322 }
 323
 324
 325 static void
 326 extend_alias_table ()
 327 {
 328   size_t new_size;
 329   struct alias_map *new_map;
 330
 331   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 332   new_map = (struct alias_map *) malloc (new_size
 333                                          * sizeof (struct alias_map));
 334   if (new_map == NULL)
 335     /* Simply don't extend: we don't have any more core.  */
 336     return;
 337
 338   memcpy (new_map, map, nmap * sizeof (struct alias_map));
 339
 340   if (maxmap != 0)
 341     free (map);
 342
 343   map = new_map;
 344   maxmap = new_size;
 345 }
 346
 347
 348 static int
 349 alias_compare (map1, map2)
 350      const struct alias_map *map1;
 351      const struct alias_map *map2;
 352 {
 353 #if defined _LIBC || defined HAVE_STRCASECMP
 354   return strcasecmp (map1->alias, map2->alias);
 355 #else
 356   const unsigned char *p1 = (const unsigned char *) map1->alias;
 357   const unsigned char *p2 = (const unsigned char *) map2->alias;
 358   unsigned char c1, c2;
 359
 360   if (p1 == p2)
 361     return 0;
 362
 363   do
 364     {
 365       /* I know this seems to be odd but the tolower() function in
 366          some systems libc cannot handle nonalpha characters.  */
 367       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 368       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 369       if (c1 == '\0')
 370         break;
 371       ++p1;
 372       ++p2;
 373     }
 374   while (c1 == c2);
 375
 376   return c1 - c2;
 377 #endif
 378 }