| 1 | /* Determine a canonical name for the current locale's character encoding. |
| 2 | |
| 3 | Copyright (C) 2000-2003 Free Software Foundation, Inc. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify it |
| 6 | under the terms of the GNU Library General Public License as published |
| 7 | by 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 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 this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, |
| 18 | USA. */ |
| 19 | |
| 20 | /* Written by Bruno Haible <bruno@clisp.org>. */ |
| 21 | |
| 22 | #ifdef HAVE_CONFIG_H |
| 23 | # include <config.h> |
| 24 | #endif |
| 25 | |
| 26 | /* Specification. */ |
| 27 | #include "localcharset.h" |
| 28 | |
| 29 | #if HAVE_STDDEF_H |
| 30 | # include <stddef.h> |
| 31 | #endif |
| 32 | |
| 33 | #include <stdio.h> |
| 34 | #if HAVE_STRING_H |
| 35 | # include <string.h> |
| 36 | #else |
| 37 | # include <strings.h> |
| 38 | #endif |
| 39 | #if HAVE_STDLIB_H |
| 40 | # include <stdlib.h> |
| 41 | #endif |
| 42 | |
| 43 | #if defined _WIN32 || defined __WIN32__ |
| 44 | # undef WIN32 /* avoid warning on mingw32 */ |
| 45 | # define WIN32 |
| 46 | #endif |
| 47 | |
| 48 | #if defined __EMX__ |
| 49 | /* Assume EMX program runs on OS/2, even if compiled under DOS. */ |
| 50 | # define OS2 |
| 51 | #endif |
| 52 | |
| 53 | #if !defined WIN32 |
| 54 | # if HAVE_LANGINFO_CODESET |
| 55 | # include <langinfo.h> |
| 56 | # else |
| 57 | # if HAVE_SETLOCALE |
| 58 | # include <locale.h> |
| 59 | # endif |
| 60 | # endif |
| 61 | #elif defined WIN32 |
| 62 | # define WIN32_LEAN_AND_MEAN |
| 63 | # include <windows.h> |
| 64 | #endif |
| 65 | #if defined OS2 |
| 66 | # define INCL_DOS |
| 67 | # include <os2.h> |
| 68 | #endif |
| 69 | |
| 70 | #if ENABLE_RELOCATABLE |
| 71 | # include "relocatable.h" |
| 72 | #else |
| 73 | # define relocate(pathname) (pathname) |
| 74 | #endif |
| 75 | |
| 76 | #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__ |
| 77 | /* Win32, OS/2, DOS */ |
| 78 | # define ISSLASH(C) ((C) == '/' || (C) == '\\') |
| 79 | #endif |
| 80 | |
| 81 | #ifndef DIRECTORY_SEPARATOR |
| 82 | # define DIRECTORY_SEPARATOR '/' |
| 83 | #endif |
| 84 | |
| 85 | #ifndef ISSLASH |
| 86 | # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR) |
| 87 | #endif |
| 88 | |
| 89 | #ifdef HAVE_GETC_UNLOCKED |
| 90 | # undef getc |
| 91 | # define getc getc_unlocked |
| 92 | #endif |
| 93 | |
| 94 | /* The following static variable is declared 'volatile' to avoid a |
| 95 | possible multithread problem in the function get_charset_aliases. If we |
| 96 | are running in a threaded environment, and if two threads initialize |
| 97 | 'charset_aliases' simultaneously, both will produce the same value, |
| 98 | and everything will be ok if the two assignments to 'charset_aliases' |
| 99 | are atomic. But I don't know what will happen if the two assignments mix. */ |
| 100 | #if __STDC__ != 1 |
| 101 | # define volatile /* empty */ |
| 102 | #endif |
| 103 | /* Pointer to the contents of the charset.alias file, if it has already been |
| 104 | read, else NULL. Its format is: |
| 105 | ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */ |
| 106 | static const char * volatile charset_aliases; |
| 107 | |
| 108 | /* Return a pointer to the contents of the charset.alias file. */ |
| 109 | static const char * |
| 110 | get_charset_aliases () |
| 111 | { |
| 112 | const char *cp; |
| 113 | |
| 114 | cp = charset_aliases; |
| 115 | if (cp == NULL) |
| 116 | { |
| 117 | #if !(defined VMS || defined WIN32) |
| 118 | FILE *fp; |
| 119 | const char *dir = relocate (LIBDIR); |
| 120 | const char *base = "charset.alias"; |
| 121 | char *file_name; |
| 122 | |
| 123 | /* Concatenate dir and base into freshly allocated file_name. */ |
| 124 | { |
| 125 | size_t dir_len = strlen (dir); |
| 126 | size_t base_len = strlen (base); |
| 127 | int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1])); |
| 128 | file_name = (char *) malloc (dir_len + add_slash + base_len + 1); |
| 129 | if (file_name != NULL) |
| 130 | { |
| 131 | memcpy (file_name, dir, dir_len); |
| 132 | if (add_slash) |
| 133 | file_name[dir_len] = DIRECTORY_SEPARATOR; |
| 134 | memcpy (file_name + dir_len + add_slash, base, base_len + 1); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | if (file_name == NULL || (fp = fopen (file_name, "r")) == NULL) |
| 139 | /* Out of memory or file not found, treat it as empty. */ |
| 140 | cp = ""; |
| 141 | else |
| 142 | { |
| 143 | /* Parse the file's contents. */ |
| 144 | int c; |
| 145 | char buf1[50+1]; |
| 146 | char buf2[50+1]; |
| 147 | char *res_ptr = NULL; |
| 148 | size_t res_size = 0; |
| 149 | size_t l1, l2; |
| 150 | |
| 151 | for (;;) |
| 152 | { |
| 153 | c = getc (fp); |
| 154 | if (c == EOF) |
| 155 | break; |
| 156 | if (c == '\n' || c == ' ' || c == '\t') |
| 157 | continue; |
| 158 | if (c == '#') |
| 159 | { |
| 160 | /* Skip comment, to end of line. */ |
| 161 | do |
| 162 | c = getc (fp); |
| 163 | while (!(c == EOF || c == '\n')); |
| 164 | if (c == EOF) |
| 165 | break; |
| 166 | continue; |
| 167 | } |
| 168 | ungetc (c, fp); |
| 169 | if (fscanf (fp, "%50s %50s", buf1, buf2) < 2) |
| 170 | break; |
| 171 | l1 = strlen (buf1); |
| 172 | l2 = strlen (buf2); |
| 173 | if (res_size == 0) |
| 174 | { |
| 175 | res_size = l1 + 1 + l2 + 1; |
| 176 | res_ptr = (char *) malloc (res_size + 1); |
| 177 | } |
| 178 | else |
| 179 | { |
| 180 | res_size += l1 + 1 + l2 + 1; |
| 181 | res_ptr = (char *) realloc (res_ptr, res_size + 1); |
| 182 | } |
| 183 | if (res_ptr == NULL) |
| 184 | { |
| 185 | /* Out of memory. */ |
| 186 | res_size = 0; |
| 187 | break; |
| 188 | } |
| 189 | strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1); |
| 190 | strcpy (res_ptr + res_size - (l2 + 1), buf2); |
| 191 | } |
| 192 | fclose (fp); |
| 193 | if (res_size == 0) |
| 194 | cp = ""; |
| 195 | else |
| 196 | { |
| 197 | *(res_ptr + res_size) = '\0'; |
| 198 | cp = res_ptr; |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | if (file_name != NULL) |
| 203 | free (file_name); |
| 204 | |
| 205 | #else |
| 206 | |
| 207 | # if defined VMS |
| 208 | /* To avoid the troubles of an extra file charset.alias_vms in the |
| 209 | sources of many GNU packages, simply inline the aliases here. */ |
| 210 | /* The list of encodings is taken from the OpenVMS 7.3-1 documentation |
| 211 | "Compaq C Run-Time Library Reference Manual for OpenVMS systems" |
| 212 | section 10.7 "Handling Different Character Sets". */ |
| 213 | cp = "ISO8859-1" "\0" "ISO-8859-1" "\0" |
| 214 | "ISO8859-2" "\0" "ISO-8859-2" "\0" |
| 215 | "ISO8859-5" "\0" "ISO-8859-5" "\0" |
| 216 | "ISO8859-7" "\0" "ISO-8859-7" "\0" |
| 217 | "ISO8859-8" "\0" "ISO-8859-8" "\0" |
| 218 | "ISO8859-9" "\0" "ISO-8859-9" "\0" |
| 219 | /* Japanese */ |
| 220 | "eucJP" "\0" "EUC-JP" "\0" |
| 221 | "SJIS" "\0" "SHIFT_JIS" "\0" |
| 222 | "DECKANJI" "\0" "DEC-KANJI" "\0" |
| 223 | "SDECKANJI" "\0" "EUC-JP" "\0" |
| 224 | /* Chinese */ |
| 225 | "eucTW" "\0" "EUC-TW" "\0" |
| 226 | "DECHANYU" "\0" "DEC-HANYU" "\0" |
| 227 | "DECHANZI" "\0" "GB2312" "\0" |
| 228 | /* Korean */ |
| 229 | "DECKOREAN" "\0" "EUC-KR" "\0"; |
| 230 | # endif |
| 231 | |
| 232 | # if defined WIN32 |
| 233 | /* To avoid the troubles of installing a separate file in the same |
| 234 | directory as the DLL and of retrieving the DLL's directory at |
| 235 | runtime, simply inline the aliases here. */ |
| 236 | |
| 237 | cp = "CP936" "\0" "GBK" "\0" |
| 238 | "CP1361" "\0" "JOHAB" "\0" |
| 239 | "CP20127" "\0" "ASCII" "\0" |
| 240 | "CP20866" "\0" "KOI8-R" "\0" |
| 241 | "CP21866" "\0" "KOI8-RU" "\0" |
| 242 | "CP28591" "\0" "ISO-8859-1" "\0" |
| 243 | "CP28592" "\0" "ISO-8859-2" "\0" |
| 244 | "CP28593" "\0" "ISO-8859-3" "\0" |
| 245 | "CP28594" "\0" "ISO-8859-4" "\0" |
| 246 | "CP28595" "\0" "ISO-8859-5" "\0" |
| 247 | "CP28596" "\0" "ISO-8859-6" "\0" |
| 248 | "CP28597" "\0" "ISO-8859-7" "\0" |
| 249 | "CP28598" "\0" "ISO-8859-8" "\0" |
| 250 | "CP28599" "\0" "ISO-8859-9" "\0" |
| 251 | "CP28605" "\0" "ISO-8859-15" "\0"; |
| 252 | # endif |
| 253 | #endif |
| 254 | |
| 255 | charset_aliases = cp; |
| 256 | } |
| 257 | |
| 258 | return cp; |
| 259 | } |
| 260 | |
| 261 | /* Determine the current locale's character encoding, and canonicalize it |
| 262 | into one of the canonical names listed in config.charset. |
| 263 | The result must not be freed; it is statically allocated. |
| 264 | If the canonical name cannot be determined, the result is a non-canonical |
| 265 | name. */ |
| 266 | |
| 267 | #ifdef STATIC |
| 268 | STATIC |
| 269 | #endif |
| 270 | const char * |
| 271 | locale_charset () |
| 272 | { |
| 273 | const char *codeset; |
| 274 | const char *aliases; |
| 275 | |
| 276 | #if !(defined WIN32 || defined OS2) |
| 277 | |
| 278 | # if HAVE_LANGINFO_CODESET |
| 279 | |
| 280 | /* Most systems support nl_langinfo (CODESET) nowadays. */ |
| 281 | codeset = nl_langinfo (CODESET); |
| 282 | |
| 283 | # else |
| 284 | |
| 285 | /* On old systems which lack it, use setlocale or getenv. */ |
| 286 | const char *locale = NULL; |
| 287 | |
| 288 | /* But most old systems don't have a complete set of locales. Some |
| 289 | (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't |
| 290 | use setlocale here; it would return "C" when it doesn't support the |
| 291 | locale name the user has set. */ |
| 292 | # if HAVE_SETLOCALE && 0 |
| 293 | locale = setlocale (LC_CTYPE, NULL); |
| 294 | # endif |
| 295 | if (locale == NULL || locale[0] == '\0') |
| 296 | { |
| 297 | locale = getenv ("LC_ALL"); |
| 298 | if (locale == NULL || locale[0] == '\0') |
| 299 | { |
| 300 | locale = getenv ("LC_CTYPE"); |
| 301 | if (locale == NULL || locale[0] == '\0') |
| 302 | locale = getenv ("LANG"); |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | /* On some old systems, one used to set locale = "iso8859_1". On others, |
| 307 | you set it to "language_COUNTRY.charset". In any case, we resolve it |
| 308 | through the charset.alias file. */ |
| 309 | codeset = locale; |
| 310 | |
| 311 | # endif |
| 312 | |
| 313 | #elif defined WIN32 |
| 314 | |
| 315 | static char buf[2 + 10 + 1]; |
| 316 | |
| 317 | /* Woe32 has a function returning the locale's codepage as a number. */ |
| 318 | sprintf (buf, "CP%u", GetACP ()); |
| 319 | codeset = buf; |
| 320 | |
| 321 | #elif defined OS2 |
| 322 | |
| 323 | const char *locale; |
| 324 | static char buf[2 + 10 + 1]; |
| 325 | ULONG cp[3]; |
| 326 | ULONG cplen; |
| 327 | |
| 328 | /* Allow user to override the codeset, as set in the operating system, |
| 329 | with standard language environment variables. */ |
| 330 | locale = getenv ("LC_ALL"); |
| 331 | if (locale == NULL || locale[0] == '\0') |
| 332 | { |
| 333 | locale = getenv ("LC_CTYPE"); |
| 334 | if (locale == NULL || locale[0] == '\0') |
| 335 | locale = getenv ("LANG"); |
| 336 | } |
| 337 | if (locale != NULL && locale[0] != '\0') |
| 338 | { |
| 339 | /* If the locale name contains an encoding after the dot, return it. */ |
| 340 | const char *dot = strchr (locale, '.'); |
| 341 | |
| 342 | if (dot != NULL) |
| 343 | { |
| 344 | const char *modifier; |
| 345 | |
| 346 | dot++; |
| 347 | /* Look for the possible @... trailer and remove it, if any. */ |
| 348 | modifier = strchr (dot, '@'); |
| 349 | if (modifier == NULL) |
| 350 | return dot; |
| 351 | if (modifier - dot < sizeof (buf)) |
| 352 | { |
| 353 | memcpy (buf, dot, modifier - dot); |
| 354 | buf [modifier - dot] = '\0'; |
| 355 | return buf; |
| 356 | } |
| 357 | } |
| 358 | |
| 359 | /* Resolve through the charset.alias file. */ |
| 360 | codeset = locale; |
| 361 | } |
| 362 | else |
| 363 | { |
| 364 | /* OS/2 has a function returning the locale's codepage as a number. */ |
| 365 | if (DosQueryCp (sizeof (cp), cp, &cplen)) |
| 366 | codeset = ""; |
| 367 | else |
| 368 | { |
| 369 | sprintf (buf, "CP%u", cp[0]); |
| 370 | codeset = buf; |
| 371 | } |
| 372 | } |
| 373 | |
| 374 | #endif |
| 375 | |
| 376 | if (codeset == NULL) |
| 377 | /* The canonical name cannot be determined. */ |
| 378 | codeset = ""; |
| 379 | |
| 380 | /* Resolve alias. */ |
| 381 | for (aliases = get_charset_aliases (); |
| 382 | *aliases != '\0'; |
| 383 | aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1) |
| 384 | if (strcmp (codeset, aliases) == 0 |
| 385 | || (aliases[0] == '*' && aliases[1] == '\0')) |
| 386 | { |
| 387 | codeset = aliases + strlen (aliases) + 1; |
| 388 | break; |
| 389 | } |
| 390 | |
| 391 | /* Don't return an empty string. GNU libc and GNU libiconv interpret |
| 392 | the empty string as denoting "the locale's character encoding", |
| 393 | thus GNU libiconv would call this function a second time. */ |
| 394 | if (codeset[0] == '\0') |
| 395 | codeset = "ASCII"; |
| 396 | |
| 397 | return codeset; |
| 398 | } |