1 /* Determine a canonical name for the current locale's character encoding.
3 Copyright (C) 2000-2006 Free Software Foundation, Inc.
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)
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.
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,
20 /* Written by Bruno Haible <bruno@clisp.org>. */
27 #include "localcharset.h"
43 #if defined _WIN32 || defined __WIN32__
48 /* Assume EMX program runs on OS/2, even if compiled under DOS. */
52 #if !defined WIN32_NATIVE
53 # if HAVE_LANGINFO_CODESET
54 # include <langinfo.h>
61 # define WIN32_LEAN_AND_MEAN
64 #elif defined WIN32_NATIVE
65 # define WIN32_LEAN_AND_MEAN
73 #if ENABLE_RELOCATABLE
74 # include "relocatable.h"
76 # define relocate(pathname) (pathname)
79 #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
80 /* Win32, Cygwin, OS/2, DOS */
81 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
84 #ifndef DIRECTORY_SEPARATOR
85 # define DIRECTORY_SEPARATOR '/'
89 # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
92 #if HAVE_DECL_GETC_UNLOCKED
94 # define getc getc_unlocked
97 /* The following static variable is declared 'volatile' to avoid a
98 possible multithread problem in the function get_charset_aliases. If we
99 are running in a threaded environment, and if two threads initialize
100 'charset_aliases' simultaneously, both will produce the same value,
101 and everything will be ok if the two assignments to 'charset_aliases'
102 are atomic. But I don't know what will happen if the two assignments mix. */
104 # define volatile /* empty */
106 /* Pointer to the contents of the charset.alias file, if it has already been
107 read, else NULL. Its format is:
108 ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */
109 static const char * volatile charset_aliases;
111 /* Return a pointer to the contents of the charset.alias file. */
113 get_charset_aliases (void)
117 cp = charset_aliases;
120 #if !(defined VMS || defined WIN32_NATIVE || defined __CYGWIN__)
123 const char *base = "charset.alias";
126 /* Make it possible to override the charset.alias location. This is
127 necessary for running the testsuite before "make install". */
128 dir = getenv ("CHARSETALIASDIR");
129 if (dir == NULL || dir[0] == '\0')
130 dir = relocate (LIBDIR);
132 /* Concatenate dir and base into freshly allocated file_name. */
134 size_t dir_len = strlen (dir);
135 size_t base_len = strlen (base);
136 int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1]));
137 file_name = (char *) malloc (dir_len + add_slash + base_len + 1);
138 if (file_name != NULL)
140 memcpy (file_name, dir, dir_len);
142 file_name[dir_len] = DIRECTORY_SEPARATOR;
143 memcpy (file_name + dir_len + add_slash, base, base_len + 1);
147 if (file_name == NULL || (fp = fopen (file_name, "r")) == NULL)
148 /* Out of memory or file not found, treat it as empty. */
152 /* Parse the file's contents. */
153 char *res_ptr = NULL;
167 if (c == '\n' || c == ' ' || c == '\t')
171 /* Skip comment, to end of line. */
174 while (!(c == EOF || c == '\n'));
180 if (fscanf (fp, "%50s %50s", buf1, buf2) < 2)
184 old_res_ptr = res_ptr;
187 res_size = l1 + 1 + l2 + 1;
188 res_ptr = (char *) malloc (res_size + 1);
192 res_size += l1 + 1 + l2 + 1;
193 res_ptr = (char *) realloc (res_ptr, res_size + 1);
199 if (old_res_ptr != NULL)
203 strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1);
204 strcpy (res_ptr + res_size - (l2 + 1), buf2);
211 *(res_ptr + res_size) = '\0';
216 if (file_name != NULL)
222 /* To avoid the troubles of an extra file charset.alias_vms in the
223 sources of many GNU packages, simply inline the aliases here. */
224 /* The list of encodings is taken from the OpenVMS 7.3-1 documentation
225 "Compaq C Run-Time Library Reference Manual for OpenVMS systems"
226 section 10.7 "Handling Different Character Sets". */
227 cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
228 "ISO8859-2" "\0" "ISO-8859-2" "\0"
229 "ISO8859-5" "\0" "ISO-8859-5" "\0"
230 "ISO8859-7" "\0" "ISO-8859-7" "\0"
231 "ISO8859-8" "\0" "ISO-8859-8" "\0"
232 "ISO8859-9" "\0" "ISO-8859-9" "\0"
234 "eucJP" "\0" "EUC-JP" "\0"
235 "SJIS" "\0" "SHIFT_JIS" "\0"
236 "DECKANJI" "\0" "DEC-KANJI" "\0"
237 "SDECKANJI" "\0" "EUC-JP" "\0"
239 "eucTW" "\0" "EUC-TW" "\0"
240 "DECHANYU" "\0" "DEC-HANYU" "\0"
241 "DECHANZI" "\0" "GB2312" "\0"
243 "DECKOREAN" "\0" "EUC-KR" "\0";
246 # if defined WIN32_NATIVE || defined __CYGWIN__
247 /* To avoid the troubles of installing a separate file in the same
248 directory as the DLL and of retrieving the DLL's directory at
249 runtime, simply inline the aliases here. */
251 cp = "CP936" "\0" "GBK" "\0"
252 "CP1361" "\0" "JOHAB" "\0"
253 "CP20127" "\0" "ASCII" "\0"
254 "CP20866" "\0" "KOI8-R" "\0"
255 "CP20936" "\0" "GB2312" "\0"
256 "CP21866" "\0" "KOI8-RU" "\0"
257 "CP28591" "\0" "ISO-8859-1" "\0"
258 "CP28592" "\0" "ISO-8859-2" "\0"
259 "CP28593" "\0" "ISO-8859-3" "\0"
260 "CP28594" "\0" "ISO-8859-4" "\0"
261 "CP28595" "\0" "ISO-8859-5" "\0"
262 "CP28596" "\0" "ISO-8859-6" "\0"
263 "CP28597" "\0" "ISO-8859-7" "\0"
264 "CP28598" "\0" "ISO-8859-8" "\0"
265 "CP28599" "\0" "ISO-8859-9" "\0"
266 "CP28605" "\0" "ISO-8859-15" "\0"
267 "CP38598" "\0" "ISO-8859-8" "\0"
268 "CP51932" "\0" "EUC-JP" "\0"
269 "CP51936" "\0" "GB2312" "\0"
270 "CP51949" "\0" "EUC-KR" "\0"
271 "CP51950" "\0" "EUC-TW" "\0"
272 "CP54936" "\0" "GB18030" "\0"
273 "CP65001" "\0" "UTF-8" "\0";
277 charset_aliases = cp;
283 /* Determine the current locale's character encoding, and canonicalize it
284 into one of the canonical names listed in config.charset.
285 The result must not be freed; it is statically allocated.
286 If the canonical name cannot be determined, the result is a non-canonical
293 locale_charset (void)
298 #if !(defined WIN32_NATIVE || defined OS2)
300 # if HAVE_LANGINFO_CODESET
302 /* Most systems support nl_langinfo (CODESET) nowadays. */
303 codeset = nl_langinfo (CODESET);
306 /* Cygwin 2006 does not have locales. nl_langinfo (CODESET) always
307 returns "US-ASCII". As long as this is not fixed, return the suffix
308 of the locale name from the environment variables (if present) or
309 the codepage as a number. */
310 if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0)
313 static char buf[2 + 10 + 1];
315 locale = getenv ("LC_ALL");
316 if (locale == NULL || locale[0] == '\0')
318 locale = getenv ("LC_CTYPE");
319 if (locale == NULL || locale[0] == '\0')
320 locale = getenv ("LANG");
322 if (locale != NULL && locale[0] != '\0')
324 /* If the locale name contains an encoding after the dot, return
326 const char *dot = strchr (locale, '.');
330 const char *modifier;
333 /* Look for the possible @... trailer and remove it, if any. */
334 modifier = strchr (dot, '@');
335 if (modifier == NULL)
337 if (modifier - dot < sizeof (buf))
339 memcpy (buf, dot, modifier - dot);
340 buf [modifier - dot] = '\0';
346 /* Woe32 has a function returning the locale's codepage as a number. */
347 sprintf (buf, "CP%u", GetACP ());
354 /* On old systems which lack it, use setlocale or getenv. */
355 const char *locale = NULL;
357 /* But most old systems don't have a complete set of locales. Some
358 (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't
359 use setlocale here; it would return "C" when it doesn't support the
360 locale name the user has set. */
361 # if HAVE_SETLOCALE && 0
362 locale = setlocale (LC_CTYPE, NULL);
364 if (locale == NULL || locale[0] == '\0')
366 locale = getenv ("LC_ALL");
367 if (locale == NULL || locale[0] == '\0')
369 locale = getenv ("LC_CTYPE");
370 if (locale == NULL || locale[0] == '\0')
371 locale = getenv ("LANG");
375 /* On some old systems, one used to set locale = "iso8859_1". On others,
376 you set it to "language_COUNTRY.charset". In any case, we resolve it
377 through the charset.alias file. */
382 #elif defined WIN32_NATIVE
384 static char buf[2 + 10 + 1];
386 /* Woe32 has a function returning the locale's codepage as a number. */
387 sprintf (buf, "CP%u", GetACP ());
393 static char buf[2 + 10 + 1];
397 /* Allow user to override the codeset, as set in the operating system,
398 with standard language environment variables. */
399 locale = getenv ("LC_ALL");
400 if (locale == NULL || locale[0] == '\0')
402 locale = getenv ("LC_CTYPE");
403 if (locale == NULL || locale[0] == '\0')
404 locale = getenv ("LANG");
406 if (locale != NULL && locale[0] != '\0')
408 /* If the locale name contains an encoding after the dot, return it. */
409 const char *dot = strchr (locale, '.');
413 const char *modifier;
416 /* Look for the possible @... trailer and remove it, if any. */
417 modifier = strchr (dot, '@');
418 if (modifier == NULL)
420 if (modifier - dot < sizeof (buf))
422 memcpy (buf, dot, modifier - dot);
423 buf [modifier - dot] = '\0';
428 /* Resolve through the charset.alias file. */
433 /* OS/2 has a function returning the locale's codepage as a number. */
434 if (DosQueryCp (sizeof (cp), cp, &cplen))
438 sprintf (buf, "CP%u", cp[0]);
446 /* The canonical name cannot be determined. */
450 for (aliases = get_charset_aliases ();
452 aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1)
453 if (strcmp (codeset, aliases) == 0
454 || (aliases[0] == '*' && aliases[1] == '\0'))
456 codeset = aliases + strlen (aliases) + 1;
460 /* Don't return an empty string. GNU libc and GNU libiconv interpret
461 the empty string as denoting "the locale's character encoding",
462 thus GNU libiconv would call this function a second time. */
463 if (codeset[0] == '\0')