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 #else
  33 # if defined HAVE_ALLOCA_H || defined _LIBC
  34 #  include <alloca.h>
  35 # else
  36 #  ifdef _AIX
  37  #pragma alloca
  38 #  else
  39 #   ifndef alloca
  40 char *alloca ();
  41 #   endif
  42 #  endif
  43 # endif
  44 #endif
  45
  46 #if defined STDC_HEADERS || defined _LIBC
  47 # include <stdlib.h>
  48 #else
  49 char *getenv ();
  50 # ifdef HAVE_MALLOC_H
  51 #  include <malloc.h>
  52 # else
  53 void free ();
  54 # endif
  55 #endif
  56
  57 #if defined HAVE_STRING_H || defined _LIBC
  58 # include <string.h>
  59 #else
  60 # include <strings.h>
  61 #endif
  62 #if !HAVE_STRCHR && !defined _LIBC
  63 # ifndef strchr
  64 #  define strchr index
  65 # endif
  66 #endif
  67
  68 #include "gettext.h"
  69 #include "gettextP.h"
  70
  71 /* @@ end of prolog @@ */
  72
  73 #ifdef _LIBC
  74 /* Rename the non ANSI C functions.  This is required by the standard
  75    because some ANSI C functions will require linking with this object
  76    file and the name space must not be polluted.  */
  77 # define strcasecmp __strcasecmp
  78 #endif
  79
  80 struct alias_map
  81 {
  82   const char *alias;
  83   const char *value;
  84 };
  85
  86
  87 static struct alias_map *map;
  88 static size_t nmap = 0;
  89 static size_t maxmap = 0;
  90
  91
  92 /* Prototypes for local functions.  */
  93 static size_t read_alias_file PARAMS ((const char *fname, int fname_len));
  94 static void extend_alias_table PARAMS ((void));
  95 static int alias_compare PARAMS ((const struct alias_map *map1,
  96                                   const struct alias_map *map2));
  97
  98
  99 const char *
 100 _nl_expand_alias (name)
 101     const char *name;
 102 {
 103   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 104   struct alias_map *retval;
 105   size_t added;
 106
 107   do
 108     {
 109       struct alias_map item;
 110
 111       item.alias = name;
 112
 113       if (nmap > 0)
 114         retval = (struct alias_map *) bsearch (&item, map, nmap,
 115                                                sizeof (struct alias_map),
 116                                                (int (*) PARAMS ((const void *,
 117                                                                  const void *))
 118                                                 ) alias_compare);
 119       else
 120         retval = NULL;
 121
 122       /* We really found an alias.  Return the value.  */
 123       if (retval != NULL)
 124         return retval->value;
 125
 126       /* Perhaps we can find another alias file.  */
 127       added = 0;
 128       while (added == 0 && locale_alias_path[0] != '\0')
 129         {
 130           const char *start;
 131
 132           while (locale_alias_path[0] == ':')
 133             ++locale_alias_path;
 134           start = locale_alias_path;
 135
 136           while (locale_alias_path[0] != '\0' && locale_alias_path[0] != ':')
 137             ++locale_alias_path;
 138
 139           if (start < locale_alias_path)
 140             added = read_alias_file (start, locale_alias_path - start);
 141         }
 142     }
 143   while (added != 0);
 144
 145   return NULL;
 146 }
 147
 148
 149 static size_t
 150 read_alias_file (fname, fname_len)
 151      const char *fname;
 152      int fname_len;
 153 {
 154   FILE *fp;
 155   char *full_fname;
 156   size_t added;
 157   static const char aliasfile[] = "/locale.alias";
 158
 159   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 160   memcpy (full_fname, fname, fname_len);
 161   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 162
 163   fp = fopen (full_fname, "r");
 164   if (fp == NULL)
 165     return 0;
 166
 167   added = 0;
 168   while (!feof (fp))
 169     {
 170       /* It is a reasonable approach to use a fix buffer here because
 171          a) we are only interested in the first two fields
 172          b) these fields must be usable as file names and so must not
 173             be that long
 174        */
 175       char buf[BUFSIZ];
 176       char *alias;
 177       char *value;
 178       char *cp;
 179
 180       if (fgets (buf, BUFSIZ, fp) == NULL)
 181         /* EOF reached.  */
 182         break;
 183
 184       cp = buf;
 185       /* Ignore leading white space.  */
 186       while (isspace (cp[0]))
 187         ++cp;
 188
 189       /* A leading '#' signals a comment line.  */
 190       if (cp[0] != '\0' && cp[0] != '#')
 191         {
 192           alias = cp++;
 193           while (cp[0] != '\0' && !isspace (cp[0]))
 194             ++cp;
 195           /* Terminate alias name.  */
 196           if (cp[0] != '\0')
 197             *cp++ = '\0';
 198
 199           /* Now look for the beginning of the value.  */
 200           while (isspace (cp[0]))
 201             ++cp;
 202
 203           if (cp[0] != '\0')
 204             {
 205               char *tp;
 206               size_t len;
 207
 208               value = cp++;
 209               while (cp[0] != '\0' && !isspace (cp[0]))
 210                 ++cp;
 211               /* Terminate value.  */
 212               if (cp[0] == '\n')
 213                 {
 214                   /* This has to be done to make the following test
 215                      for the end of line possible.  We are looking for
 216                      the terminating '\n' which do not overwrite here.  */
 217                   *cp++ = '\0';
 218                   *cp = '\n';
 219                 }
 220               else if (cp[0] != '\0')
 221                 *cp++ = '\0';
 222
 223               if (nmap >= maxmap)
 224                 extend_alias_table ();
 225
 226               /* We cannot depend on strdup available in the libc.  Sigh!  */
 227               len = strlen (alias) + 1;
 228               tp = (char *) malloc (len);
 229               if (tp == NULL)
 230                 return added;
 231               memcpy (tp, alias, len);
 232               map[nmap].alias = tp;
 233
 234               len = strlen (value) + 1;
 235               tp = (char *) malloc (len);
 236               if (tp == NULL)
 237                 return added;
 238               memcpy (tp, value, len);
 239               map[nmap].value = tp;
 240
 241               ++nmap;
 242               ++added;
 243             }
 244         }
 245
 246       /* Possibily not the whole line fitted into the buffer.  Ignore
 247          the rest of the line.  */
 248       while (strchr (cp, '\n') == NULL)
 249         {
 250           cp = buf;
 251           if (fgets (buf, BUFSIZ, fp) == NULL)
 252             /* Make sure the inner loop will be left.  The outer loop
 253                will exit at the `feof' test.  */
 254             *cp = '\n';
 255         }
 256     }
 257
 258   /* Should we test for ferror()?  I think we have to silently ignore
 259      errors.  --drepper  */
 260   fclose (fp);
 261
 262   if (added > 0)
 263     qsort (map, nmap, sizeof (struct alias_map),
 264            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 265
 266   return added;
 267 }
 268
 269
 270 static void
 271 extend_alias_table ()
 272 {
 273   size_t new_size;
 274   struct alias_map *new_map;
 275
 276   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 277   new_map = (struct alias_map *) malloc (new_size
 278                                          * sizeof (struct alias_map));
 279   if (new_map == NULL)
 280     /* Simply don't extend: we don't have any more core.  */
 281     return;
 282
 283   memcpy (new_map, map, nmap * sizeof (struct alias_map));
 284
 285   if (maxmap != 0)
 286     free (map);
 287
 288   map = new_map;
 289   maxmap = new_size;
 290 }
 291
 292
 293 static int
 294 alias_compare (map1, map2)
 295      const struct alias_map *map1;
 296      const struct alias_map *map2;
 297 {
 298 #if defined _LIBC || defined HAVE_STRCASECMP
 299   return strcasecmp (map1->alias, map2->alias);
 300 #else
 301   const unsigned char *p1 = (const unsigned char *) map1->alias;
 302   const unsigned char *p2 = (const unsigned char *) map2->alias;
 303   unsigned char c1, c2;
 304
 305   if (p1 == p2)
 306     return 0;
 307
 308   do
 309     {
 310       /* I know this seems to be odd but the tolower() function in
 311          some systems libc cannot handle nonalpha characters.  */
 312       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 313       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 314       if (c1 == '\0')
 315         break;
 316       ++p1;
 317       ++p2;
 318     }
 319   while (c1 == c2);
 320
 321   return c1 - c2;
 322 #endif
 323 }