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c2c2b5a4 LC |
1 | /* Determine a canonical name for the current locale's character encoding. |
2 | ||
3 | Copyright (C) 2000-2006, 2008-2011 Free Software Foundation, Inc. | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU Lesser 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 Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public License along | |
16 | with this program; if not, write to the Free Software Foundation, | |
17 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
18 | ||
19 | /* Written by Bruno Haible <bruno@clisp.org>. */ | |
20 | ||
21 | #include <config.h> | |
22 | ||
23 | /* Specification. */ | |
24 | #include "localcharset.h" | |
25 | ||
26 | #include <fcntl.h> | |
27 | #include <stddef.h> | |
28 | #include <stdio.h> | |
29 | #include <string.h> | |
30 | #include <stdlib.h> | |
31 | ||
32 | #if defined __APPLE__ && defined __MACH__ && HAVE_LANGINFO_CODESET | |
33 | # define DARWIN7 /* Darwin 7 or newer, i.e. MacOS X 10.3 or newer */ | |
34 | #endif | |
35 | ||
36 | #if defined _WIN32 || defined __WIN32__ | |
37 | # define WIN32_NATIVE | |
38 | #endif | |
39 | ||
40 | #if defined __EMX__ | |
41 | /* Assume EMX program runs on OS/2, even if compiled under DOS. */ | |
42 | # ifndef OS2 | |
43 | # define OS2 | |
44 | # endif | |
45 | #endif | |
46 | ||
47 | #if !defined WIN32_NATIVE | |
48 | # include <unistd.h> | |
49 | # if HAVE_LANGINFO_CODESET | |
50 | # include <langinfo.h> | |
51 | # else | |
52 | # if 0 /* see comment below */ | |
53 | # include <locale.h> | |
54 | # endif | |
55 | # endif | |
56 | # ifdef __CYGWIN__ | |
57 | # define WIN32_LEAN_AND_MEAN | |
58 | # include <windows.h> | |
59 | # endif | |
60 | #elif defined WIN32_NATIVE | |
61 | # define WIN32_LEAN_AND_MEAN | |
62 | # include <windows.h> | |
63 | #endif | |
64 | #if defined OS2 | |
65 | # define INCL_DOS | |
66 | # include <os2.h> | |
67 | #endif | |
68 | ||
69 | #if ENABLE_RELOCATABLE | |
70 | # include "relocatable.h" | |
71 | #else | |
72 | # define relocate(pathname) (pathname) | |
73 | #endif | |
74 | ||
75 | /* Get LIBDIR. */ | |
76 | #ifndef LIBDIR | |
77 | # include "configmake.h" | |
78 | #endif | |
79 | ||
80 | /* Define O_NOFOLLOW to 0 on platforms where it does not exist. */ | |
81 | #ifndef O_NOFOLLOW | |
82 | # define O_NOFOLLOW 0 | |
83 | #endif | |
84 | ||
85 | #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__ | |
86 | /* Win32, Cygwin, OS/2, DOS */ | |
87 | # define ISSLASH(C) ((C) == '/' || (C) == '\\') | |
88 | #endif | |
89 | ||
90 | #ifndef DIRECTORY_SEPARATOR | |
91 | # define DIRECTORY_SEPARATOR '/' | |
92 | #endif | |
93 | ||
94 | #ifndef ISSLASH | |
95 | # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR) | |
96 | #endif | |
97 | ||
98 | #if HAVE_DECL_GETC_UNLOCKED | |
99 | # undef getc | |
100 | # define getc getc_unlocked | |
101 | #endif | |
102 | ||
103 | /* The following static variable is declared 'volatile' to avoid a | |
104 | possible multithread problem in the function get_charset_aliases. If we | |
105 | are running in a threaded environment, and if two threads initialize | |
106 | 'charset_aliases' simultaneously, both will produce the same value, | |
107 | and everything will be ok if the two assignments to 'charset_aliases' | |
108 | are atomic. But I don't know what will happen if the two assignments mix. */ | |
109 | #if __STDC__ != 1 | |
110 | # define volatile /* empty */ | |
111 | #endif | |
112 | /* Pointer to the contents of the charset.alias file, if it has already been | |
113 | read, else NULL. Its format is: | |
114 | ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */ | |
115 | static const char * volatile charset_aliases; | |
116 | ||
117 | /* Return a pointer to the contents of the charset.alias file. */ | |
118 | static const char * | |
119 | get_charset_aliases (void) | |
120 | { | |
121 | const char *cp; | |
122 | ||
123 | cp = charset_aliases; | |
124 | if (cp == NULL) | |
125 | { | |
126 | #if !(defined DARWIN7 || defined VMS || defined WIN32_NATIVE || defined __CYGWIN__) | |
127 | const char *dir; | |
128 | const char *base = "charset.alias"; | |
129 | char *file_name; | |
130 | ||
131 | /* Make it possible to override the charset.alias location. This is | |
132 | necessary for running the testsuite before "make install". */ | |
133 | dir = getenv ("CHARSETALIASDIR"); | |
134 | if (dir == NULL || dir[0] == '\0') | |
135 | dir = relocate (LIBDIR); | |
136 | ||
137 | /* Concatenate dir and base into freshly allocated file_name. */ | |
138 | { | |
139 | size_t dir_len = strlen (dir); | |
140 | size_t base_len = strlen (base); | |
141 | int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1])); | |
142 | file_name = (char *) malloc (dir_len + add_slash + base_len + 1); | |
143 | if (file_name != NULL) | |
144 | { | |
145 | memcpy (file_name, dir, dir_len); | |
146 | if (add_slash) | |
147 | file_name[dir_len] = DIRECTORY_SEPARATOR; | |
148 | memcpy (file_name + dir_len + add_slash, base, base_len + 1); | |
149 | } | |
150 | } | |
151 | ||
152 | if (file_name == NULL) | |
153 | /* Out of memory. Treat the file as empty. */ | |
154 | cp = ""; | |
155 | else | |
156 | { | |
157 | int fd; | |
158 | ||
159 | /* Open the file. Reject symbolic links on platforms that support | |
160 | O_NOFOLLOW. This is a security feature. Without it, an attacker | |
161 | could retrieve parts of the contents (namely, the tail of the | |
162 | first line that starts with "* ") of an arbitrary file by placing | |
163 | a symbolic link to that file under the name "charset.alias" in | |
164 | some writable directory and defining the environment variable | |
165 | CHARSETALIASDIR to point to that directory. */ | |
166 | fd = open (file_name, | |
167 | O_RDONLY | (HAVE_WORKING_O_NOFOLLOW ? O_NOFOLLOW : 0)); | |
168 | if (fd < 0) | |
169 | /* File not found. Treat it as empty. */ | |
170 | cp = ""; | |
171 | else | |
172 | { | |
173 | FILE *fp; | |
174 | ||
175 | fp = fdopen (fd, "r"); | |
176 | if (fp == NULL) | |
177 | { | |
178 | /* Out of memory. Treat the file as empty. */ | |
179 | close (fd); | |
180 | cp = ""; | |
181 | } | |
182 | else | |
183 | { | |
184 | /* Parse the file's contents. */ | |
185 | char *res_ptr = NULL; | |
186 | size_t res_size = 0; | |
187 | ||
188 | for (;;) | |
189 | { | |
190 | int c; | |
191 | char buf1[50+1]; | |
192 | char buf2[50+1]; | |
193 | size_t l1, l2; | |
194 | char *old_res_ptr; | |
195 | ||
196 | c = getc (fp); | |
197 | if (c == EOF) | |
198 | break; | |
199 | if (c == '\n' || c == ' ' || c == '\t') | |
200 | continue; | |
201 | if (c == '#') | |
202 | { | |
203 | /* Skip comment, to end of line. */ | |
204 | do | |
205 | c = getc (fp); | |
206 | while (!(c == EOF || c == '\n')); | |
207 | if (c == EOF) | |
208 | break; | |
209 | continue; | |
210 | } | |
211 | ungetc (c, fp); | |
212 | if (fscanf (fp, "%50s %50s", buf1, buf2) < 2) | |
213 | break; | |
214 | l1 = strlen (buf1); | |
215 | l2 = strlen (buf2); | |
216 | old_res_ptr = res_ptr; | |
217 | if (res_size == 0) | |
218 | { | |
219 | res_size = l1 + 1 + l2 + 1; | |
220 | res_ptr = (char *) malloc (res_size + 1); | |
221 | } | |
222 | else | |
223 | { | |
224 | res_size += l1 + 1 + l2 + 1; | |
225 | res_ptr = (char *) realloc (res_ptr, res_size + 1); | |
226 | } | |
227 | if (res_ptr == NULL) | |
228 | { | |
229 | /* Out of memory. */ | |
230 | res_size = 0; | |
231 | free (old_res_ptr); | |
232 | break; | |
233 | } | |
234 | strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1); | |
235 | strcpy (res_ptr + res_size - (l2 + 1), buf2); | |
236 | } | |
237 | fclose (fp); | |
238 | if (res_size == 0) | |
239 | cp = ""; | |
240 | else | |
241 | { | |
242 | *(res_ptr + res_size) = '\0'; | |
243 | cp = res_ptr; | |
244 | } | |
245 | } | |
246 | } | |
247 | ||
248 | free (file_name); | |
249 | } | |
250 | ||
251 | #else | |
252 | ||
253 | # if defined DARWIN7 | |
254 | /* To avoid the trouble of installing a file that is shared by many | |
255 | GNU packages -- many packaging systems have problems with this --, | |
256 | simply inline the aliases here. */ | |
257 | cp = "ISO8859-1" "\0" "ISO-8859-1" "\0" | |
258 | "ISO8859-2" "\0" "ISO-8859-2" "\0" | |
259 | "ISO8859-4" "\0" "ISO-8859-4" "\0" | |
260 | "ISO8859-5" "\0" "ISO-8859-5" "\0" | |
261 | "ISO8859-7" "\0" "ISO-8859-7" "\0" | |
262 | "ISO8859-9" "\0" "ISO-8859-9" "\0" | |
263 | "ISO8859-13" "\0" "ISO-8859-13" "\0" | |
264 | "ISO8859-15" "\0" "ISO-8859-15" "\0" | |
265 | "KOI8-R" "\0" "KOI8-R" "\0" | |
266 | "KOI8-U" "\0" "KOI8-U" "\0" | |
267 | "CP866" "\0" "CP866" "\0" | |
268 | "CP949" "\0" "CP949" "\0" | |
269 | "CP1131" "\0" "CP1131" "\0" | |
270 | "CP1251" "\0" "CP1251" "\0" | |
271 | "eucCN" "\0" "GB2312" "\0" | |
272 | "GB2312" "\0" "GB2312" "\0" | |
273 | "eucJP" "\0" "EUC-JP" "\0" | |
274 | "eucKR" "\0" "EUC-KR" "\0" | |
275 | "Big5" "\0" "BIG5" "\0" | |
276 | "Big5HKSCS" "\0" "BIG5-HKSCS" "\0" | |
277 | "GBK" "\0" "GBK" "\0" | |
278 | "GB18030" "\0" "GB18030" "\0" | |
279 | "SJIS" "\0" "SHIFT_JIS" "\0" | |
280 | "ARMSCII-8" "\0" "ARMSCII-8" "\0" | |
281 | "PT154" "\0" "PT154" "\0" | |
282 | /*"ISCII-DEV" "\0" "?" "\0"*/ | |
283 | "*" "\0" "UTF-8" "\0"; | |
284 | # endif | |
285 | ||
286 | # if defined VMS | |
287 | /* To avoid the troubles of an extra file charset.alias_vms in the | |
288 | sources of many GNU packages, simply inline the aliases here. */ | |
289 | /* The list of encodings is taken from the OpenVMS 7.3-1 documentation | |
290 | "Compaq C Run-Time Library Reference Manual for OpenVMS systems" | |
291 | section 10.7 "Handling Different Character Sets". */ | |
292 | cp = "ISO8859-1" "\0" "ISO-8859-1" "\0" | |
293 | "ISO8859-2" "\0" "ISO-8859-2" "\0" | |
294 | "ISO8859-5" "\0" "ISO-8859-5" "\0" | |
295 | "ISO8859-7" "\0" "ISO-8859-7" "\0" | |
296 | "ISO8859-8" "\0" "ISO-8859-8" "\0" | |
297 | "ISO8859-9" "\0" "ISO-8859-9" "\0" | |
298 | /* Japanese */ | |
299 | "eucJP" "\0" "EUC-JP" "\0" | |
300 | "SJIS" "\0" "SHIFT_JIS" "\0" | |
301 | "DECKANJI" "\0" "DEC-KANJI" "\0" | |
302 | "SDECKANJI" "\0" "EUC-JP" "\0" | |
303 | /* Chinese */ | |
304 | "eucTW" "\0" "EUC-TW" "\0" | |
305 | "DECHANYU" "\0" "DEC-HANYU" "\0" | |
306 | "DECHANZI" "\0" "GB2312" "\0" | |
307 | /* Korean */ | |
308 | "DECKOREAN" "\0" "EUC-KR" "\0"; | |
309 | # endif | |
310 | ||
311 | # if defined WIN32_NATIVE || defined __CYGWIN__ | |
312 | /* To avoid the troubles of installing a separate file in the same | |
313 | directory as the DLL and of retrieving the DLL's directory at | |
314 | runtime, simply inline the aliases here. */ | |
315 | ||
316 | cp = "CP936" "\0" "GBK" "\0" | |
317 | "CP1361" "\0" "JOHAB" "\0" | |
318 | "CP20127" "\0" "ASCII" "\0" | |
319 | "CP20866" "\0" "KOI8-R" "\0" | |
320 | "CP20936" "\0" "GB2312" "\0" | |
321 | "CP21866" "\0" "KOI8-RU" "\0" | |
322 | "CP28591" "\0" "ISO-8859-1" "\0" | |
323 | "CP28592" "\0" "ISO-8859-2" "\0" | |
324 | "CP28593" "\0" "ISO-8859-3" "\0" | |
325 | "CP28594" "\0" "ISO-8859-4" "\0" | |
326 | "CP28595" "\0" "ISO-8859-5" "\0" | |
327 | "CP28596" "\0" "ISO-8859-6" "\0" | |
328 | "CP28597" "\0" "ISO-8859-7" "\0" | |
329 | "CP28598" "\0" "ISO-8859-8" "\0" | |
330 | "CP28599" "\0" "ISO-8859-9" "\0" | |
331 | "CP28605" "\0" "ISO-8859-15" "\0" | |
332 | "CP38598" "\0" "ISO-8859-8" "\0" | |
333 | "CP51932" "\0" "EUC-JP" "\0" | |
334 | "CP51936" "\0" "GB2312" "\0" | |
335 | "CP51949" "\0" "EUC-KR" "\0" | |
336 | "CP51950" "\0" "EUC-TW" "\0" | |
337 | "CP54936" "\0" "GB18030" "\0" | |
338 | "CP65001" "\0" "UTF-8" "\0"; | |
339 | # endif | |
340 | #endif | |
341 | ||
342 | charset_aliases = cp; | |
343 | } | |
344 | ||
345 | return cp; | |
346 | } | |
347 | ||
348 | /* Determine the current locale's character encoding, and canonicalize it | |
349 | into one of the canonical names listed in config.charset. | |
350 | The result must not be freed; it is statically allocated. | |
351 | If the canonical name cannot be determined, the result is a non-canonical | |
352 | name. */ | |
353 | ||
354 | #ifdef STATIC | |
355 | STATIC | |
356 | #endif | |
357 | const char * | |
358 | locale_charset (void) | |
359 | { | |
360 | const char *codeset; | |
361 | const char *aliases; | |
362 | ||
363 | #if !(defined WIN32_NATIVE || defined OS2) | |
364 | ||
365 | # if HAVE_LANGINFO_CODESET | |
366 | ||
367 | /* Most systems support nl_langinfo (CODESET) nowadays. */ | |
368 | codeset = nl_langinfo (CODESET); | |
369 | ||
370 | # ifdef __CYGWIN__ | |
371 | /* Cygwin < 1.7 does not have locales. nl_langinfo (CODESET) always | |
372 | returns "US-ASCII". Return the suffix of the locale name from the | |
373 | environment variables (if present) or the codepage as a number. */ | |
374 | if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0) | |
375 | { | |
376 | const char *locale; | |
377 | static char buf[2 + 10 + 1]; | |
378 | ||
379 | locale = getenv ("LC_ALL"); | |
380 | if (locale == NULL || locale[0] == '\0') | |
381 | { | |
382 | locale = getenv ("LC_CTYPE"); | |
383 | if (locale == NULL || locale[0] == '\0') | |
384 | locale = getenv ("LANG"); | |
385 | } | |
386 | if (locale != NULL && locale[0] != '\0') | |
387 | { | |
388 | /* If the locale name contains an encoding after the dot, return | |
389 | it. */ | |
390 | const char *dot = strchr (locale, '.'); | |
391 | ||
392 | if (dot != NULL) | |
393 | { | |
394 | const char *modifier; | |
395 | ||
396 | dot++; | |
397 | /* Look for the possible @... trailer and remove it, if any. */ | |
398 | modifier = strchr (dot, '@'); | |
399 | if (modifier == NULL) | |
400 | return dot; | |
401 | if (modifier - dot < sizeof (buf)) | |
402 | { | |
403 | memcpy (buf, dot, modifier - dot); | |
404 | buf [modifier - dot] = '\0'; | |
405 | return buf; | |
406 | } | |
407 | } | |
408 | } | |
409 | ||
410 | /* Woe32 has a function returning the locale's codepage as a number: | |
411 | GetACP(). This encoding is used by Cygwin, unless the user has set | |
412 | the environment variable CYGWIN=codepage:oem (which very few people | |
413 | do). | |
414 | Output directed to console windows needs to be converted (to | |
415 | GetOEMCP() if the console is using a raster font, or to | |
416 | GetConsoleOutputCP() if it is using a TrueType font). Cygwin does | |
417 | this conversion transparently (see winsup/cygwin/fhandler_console.cc), | |
418 | converting to GetConsoleOutputCP(). This leads to correct results, | |
419 | except when SetConsoleOutputCP has been called and a raster font is | |
420 | in use. */ | |
421 | sprintf (buf, "CP%u", GetACP ()); | |
422 | codeset = buf; | |
423 | } | |
424 | # endif | |
425 | ||
426 | # else | |
427 | ||
428 | /* On old systems which lack it, use setlocale or getenv. */ | |
429 | const char *locale = NULL; | |
430 | ||
431 | /* But most old systems don't have a complete set of locales. Some | |
432 | (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't | |
433 | use setlocale here; it would return "C" when it doesn't support the | |
434 | locale name the user has set. */ | |
435 | # if 0 | |
436 | locale = setlocale (LC_CTYPE, NULL); | |
437 | # endif | |
438 | if (locale == NULL || locale[0] == '\0') | |
439 | { | |
440 | locale = getenv ("LC_ALL"); | |
441 | if (locale == NULL || locale[0] == '\0') | |
442 | { | |
443 | locale = getenv ("LC_CTYPE"); | |
444 | if (locale == NULL || locale[0] == '\0') | |
445 | locale = getenv ("LANG"); | |
446 | } | |
447 | } | |
448 | ||
449 | /* On some old systems, one used to set locale = "iso8859_1". On others, | |
450 | you set it to "language_COUNTRY.charset". In any case, we resolve it | |
451 | through the charset.alias file. */ | |
452 | codeset = locale; | |
453 | ||
454 | # endif | |
455 | ||
456 | #elif defined WIN32_NATIVE | |
457 | ||
458 | static char buf[2 + 10 + 1]; | |
459 | ||
460 | /* Woe32 has a function returning the locale's codepage as a number: | |
461 | GetACP(). | |
462 | When the output goes to a console window, it needs to be provided in | |
463 | GetOEMCP() encoding if the console is using a raster font, or in | |
464 | GetConsoleOutputCP() encoding if it is using a TrueType font. | |
465 | But in GUI programs and for output sent to files and pipes, GetACP() | |
466 | encoding is the best bet. */ | |
467 | sprintf (buf, "CP%u", GetACP ()); | |
468 | codeset = buf; | |
469 | ||
470 | #elif defined OS2 | |
471 | ||
472 | const char *locale; | |
473 | static char buf[2 + 10 + 1]; | |
474 | ULONG cp[3]; | |
475 | ULONG cplen; | |
476 | ||
477 | /* Allow user to override the codeset, as set in the operating system, | |
478 | with standard language environment variables. */ | |
479 | locale = getenv ("LC_ALL"); | |
480 | if (locale == NULL || locale[0] == '\0') | |
481 | { | |
482 | locale = getenv ("LC_CTYPE"); | |
483 | if (locale == NULL || locale[0] == '\0') | |
484 | locale = getenv ("LANG"); | |
485 | } | |
486 | if (locale != NULL && locale[0] != '\0') | |
487 | { | |
488 | /* If the locale name contains an encoding after the dot, return it. */ | |
489 | const char *dot = strchr (locale, '.'); | |
490 | ||
491 | if (dot != NULL) | |
492 | { | |
493 | const char *modifier; | |
494 | ||
495 | dot++; | |
496 | /* Look for the possible @... trailer and remove it, if any. */ | |
497 | modifier = strchr (dot, '@'); | |
498 | if (modifier == NULL) | |
499 | return dot; | |
500 | if (modifier - dot < sizeof (buf)) | |
501 | { | |
502 | memcpy (buf, dot, modifier - dot); | |
503 | buf [modifier - dot] = '\0'; | |
504 | return buf; | |
505 | } | |
506 | } | |
507 | ||
508 | /* Resolve through the charset.alias file. */ | |
509 | codeset = locale; | |
510 | } | |
511 | else | |
512 | { | |
513 | /* OS/2 has a function returning the locale's codepage as a number. */ | |
514 | if (DosQueryCp (sizeof (cp), cp, &cplen)) | |
515 | codeset = ""; | |
516 | else | |
517 | { | |
518 | sprintf (buf, "CP%u", cp[0]); | |
519 | codeset = buf; | |
520 | } | |
521 | } | |
522 | ||
523 | #endif | |
524 | ||
525 | if (codeset == NULL) | |
526 | /* The canonical name cannot be determined. */ | |
527 | codeset = ""; | |
528 | ||
529 | /* Resolve alias. */ | |
530 | for (aliases = get_charset_aliases (); | |
531 | *aliases != '\0'; | |
532 | aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1) | |
533 | if (strcmp (codeset, aliases) == 0 | |
534 | || (aliases[0] == '*' && aliases[1] == '\0')) | |
535 | { | |
536 | codeset = aliases + strlen (aliases) + 1; | |
537 | break; | |
538 | } | |
539 | ||
540 | /* Don't return an empty string. GNU libc and GNU libiconv interpret | |
541 | the empty string as denoting "the locale's character encoding", | |
542 | thus GNU libiconv would call this function a second time. */ | |
543 | if (codeset[0] == '\0') | |
544 | codeset = "ASCII"; | |
545 | ||
546 | return codeset; | |
547 | } | |
548 | ||
549 | /* A variant of the above, without calls to `setlocale', `nl_langinfo', | |
550 | etc. */ | |
551 | const char * | |
552 | environ_locale_charset (void) | |
553 | { | |
554 | static char buf[2 + 10 + 1]; | |
555 | const char *codeset, *aliases; | |
556 | const char *locale = NULL; | |
557 | ||
558 | locale = getenv ("LC_ALL"); | |
559 | if (locale == NULL || locale[0] == '\0') | |
560 | { | |
561 | locale = getenv ("LC_CTYPE"); | |
562 | if (locale == NULL || locale[0] == '\0') | |
563 | locale = getenv ("LANG"); | |
564 | } | |
565 | ||
566 | if (locale != NULL && locale[0] != '\0') | |
567 | { | |
568 | /* If the locale name contains an encoding after the dot, return it. */ | |
569 | const char *dot = strchr (locale, '.'); | |
570 | ||
571 | if (dot != NULL) | |
572 | { | |
573 | const char *modifier; | |
574 | ||
575 | dot++; | |
576 | /* Look for the possible @... trailer and remove it, if any. */ | |
577 | modifier = strchr (dot, '@'); | |
578 | if (modifier == NULL) | |
579 | return dot; | |
580 | if (modifier - dot < sizeof (buf)) | |
581 | { | |
582 | memcpy (buf, dot, modifier - dot); | |
583 | buf [modifier - dot] = '\0'; | |
584 | return buf; | |
585 | } | |
586 | } | |
587 | else if (strcmp (locale, "C") == 0) | |
588 | { | |
589 | strcpy (buf, "ASCII"); | |
590 | return buf; | |
591 | } | |
592 | ||
593 | /* Resolve through the charset.alias file. */ | |
594 | codeset = locale; | |
595 | } | |
596 | else | |
597 | codeset = ""; | |
598 | ||
599 | /* Resolve alias. */ | |
600 | for (aliases = get_charset_aliases (); | |
601 | *aliases != '\0'; | |
602 | aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1) | |
603 | if (strcmp (codeset, aliases) == 0 | |
604 | || (aliases[0] == '*' && aliases[1] == '\0')) | |
605 | { | |
606 | codeset = aliases + strlen (aliases) + 1; | |
607 | break; | |
608 | } | |
609 | ||
610 | /* Don't return an empty string. GNU libc and GNU libiconv interpret | |
611 | the empty string as denoting "the locale's character encoding", | |
612 | thus GNU libiconv would call this function a second time. */ | |
613 | if (codeset[0] == '\0') | |
614 | codeset = "ASCII"; | |
615 | ||
616 | return codeset; | |
617 | } |