Edit
thodg/libiconv/libcharset/lib/localcharset.c
Bruno Haible
- libcharset/lib/localcharset.c
-
/* Determine a canonical name for the current locale's character encoding. Copyright (C) 2000-2006, 2008-2009 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* Written by Bruno Haible <bruno@clisp.org>. */ #include <config.h> /* Specification. */ #include "localcharset.h" #include <fcntl.h> #include <stddef.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #if defined __APPLE__ && defined __MACH__ && HAVE_LANGINFO_CODESET # define DARWIN7 /* Darwin 7 or newer, i.e. MacOS X 10.3 or newer */ #endif #if defined _WIN32 || defined __WIN32__ # define WIN32_NATIVE #endif #if defined __EMX__ /* Assume EMX program runs on OS/2, even if compiled under DOS. */ # ifndef OS2 # define OS2 # endif #endif #if !defined WIN32_NATIVE # include <unistd.h> # if HAVE_LANGINFO_CODESET # include <langinfo.h> # else # if 0 /* see comment below */ # include <locale.h> # endif # endif # ifdef __CYGWIN__ # define WIN32_LEAN_AND_MEAN # include <windows.h> # endif #elif defined WIN32_NATIVE # define WIN32_LEAN_AND_MEAN # include <windows.h> #endif #if defined OS2 # define INCL_DOS # include <os2.h> #endif #if ENABLE_RELOCATABLE # include "relocatable.h" #else # define relocate(pathname) (pathname) #endif /* Get LIBDIR. */ #ifndef LIBDIR # include "configmake.h" #endif /* Define O_NOFOLLOW to 0 on platforms where it does not exist. */ #ifndef O_NOFOLLOW # define O_NOFOLLOW 0 #endif #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__ /* Win32, Cygwin, OS/2, DOS */ # define ISSLASH(C) ((C) == '/' || (C) == '\\') #endif #ifndef DIRECTORY_SEPARATOR # define DIRECTORY_SEPARATOR '/' #endif #ifndef ISSLASH # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR) #endif #if HAVE_DECL_GETC_UNLOCKED # undef getc # define getc getc_unlocked #endif /* The following static variable is declared 'volatile' to avoid a possible multithread problem in the function get_charset_aliases. If we are running in a threaded environment, and if two threads initialize 'charset_aliases' simultaneously, both will produce the same value, and everything will be ok if the two assignments to 'charset_aliases' are atomic. But I don't know what will happen if the two assignments mix. */ #if __STDC__ != 1 # define volatile /* empty */ #endif /* Pointer to the contents of the charset.alias file, if it has already been read, else NULL. Its format is: ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */ static const char * volatile charset_aliases; /* Return a pointer to the contents of the charset.alias file. */ static const char * get_charset_aliases (void) { const char *cp; cp = charset_aliases; if (cp == NULL) { #if !(defined DARWIN7 || defined VMS || defined WIN32_NATIVE || defined __CYGWIN__) const char *dir; const char *base = "charset.alias"; char *file_name; /* Make it possible to override the charset.alias location. This is necessary for running the testsuite before "make install". */ dir = getenv ("CHARSETALIASDIR"); if (dir == NULL || dir[0] == '\0') dir = relocate (LIBDIR); /* Concatenate dir and base into freshly allocated file_name. */ { size_t dir_len = strlen (dir); size_t base_len = strlen (base); int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1])); file_name = (char *) malloc (dir_len + add_slash + base_len + 1); if (file_name != NULL) { memcpy (file_name, dir, dir_len); if (add_slash) file_name[dir_len] = DIRECTORY_SEPARATOR; memcpy (file_name + dir_len + add_slash, base, base_len + 1); } } if (file_name == NULL) /* Out of memory. Treat the file as empty. */ cp = ""; else { int fd; /* Open the file. Reject symbolic links on platforms that support O_NOFOLLOW. This is a security feature. Without it, an attacker could retrieve parts of the contents (namely, the tail of the first line that starts with "* ") of an arbitrary file by placing a symbolic link to that file under the name "charset.alias" in some writable directory and defining the environment variable CHARSETALIASDIR to point to that directory. */ fd = open (file_name, O_RDONLY | (HAVE_WORKING_O_NOFOLLOW ? O_NOFOLLOW : 0)); if (fd < 0) /* File not found. Treat it as empty. */ cp = ""; else { FILE *fp; fp = fdopen (fd, "r"); if (fp == NULL) { /* Out of memory. Treat the file as empty. */ close (fd); cp = ""; } else { /* Parse the file's contents. */ char *res_ptr = NULL; size_t res_size = 0; for (;;) { int c; char buf1[50+1]; char buf2[50+1]; size_t l1, l2; char *old_res_ptr; c = getc (fp); if (c == EOF) break; if (c == '\n' || c == ' ' || c == '\t') continue; if (c == '#') { /* Skip comment, to end of line. */ do c = getc (fp); while (!(c == EOF || c == '\n')); if (c == EOF) break; continue; } ungetc (c, fp); if (fscanf (fp, "%50s %50s", buf1, buf2) < 2) break; l1 = strlen (buf1); l2 = strlen (buf2); old_res_ptr = res_ptr; if (res_size == 0) { res_size = l1 + 1 + l2 + 1; res_ptr = (char *) malloc (res_size + 1); } else { res_size += l1 + 1 + l2 + 1; res_ptr = (char *) realloc (res_ptr, res_size + 1); } if (res_ptr == NULL) { /* Out of memory. */ res_size = 0; if (old_res_ptr != NULL) free (old_res_ptr); break; } strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1); strcpy (res_ptr + res_size - (l2 + 1), buf2); } fclose (fp); if (res_size == 0) cp = ""; else { *(res_ptr + res_size) = '\0'; cp = res_ptr; } } } free (file_name); } #else # if defined DARWIN7 /* To avoid the trouble of installing a file that is shared by many GNU packages -- many packaging systems have problems with this --, simply inline the aliases here. */ cp = "ISO8859-1" "\0" "ISO-8859-1" "\0" "ISO8859-2" "\0" "ISO-8859-2" "\0" "ISO8859-4" "\0" "ISO-8859-4" "\0" "ISO8859-5" "\0" "ISO-8859-5" "\0" "ISO8859-7" "\0" "ISO-8859-7" "\0" "ISO8859-9" "\0" "ISO-8859-9" "\0" "ISO8859-13" "\0" "ISO-8859-13" "\0" "ISO8859-15" "\0" "ISO-8859-15" "\0" "KOI8-R" "\0" "KOI8-R" "\0" "KOI8-U" "\0" "KOI8-U" "\0" "CP866" "\0" "CP866" "\0" "CP949" "\0" "CP949" "\0" "CP1131" "\0" "CP1131" "\0" "CP1251" "\0" "CP1251" "\0" "eucCN" "\0" "GB2312" "\0" "GB2312" "\0" "GB2312" "\0" "eucJP" "\0" "EUC-JP" "\0" "eucKR" "\0" "EUC-KR" "\0" "Big5" "\0" "BIG5" "\0" "Big5HKSCS" "\0" "BIG5-HKSCS" "\0" "GBK" "\0" "GBK" "\0" "GB18030" "\0" "GB18030" "\0" "SJIS" "\0" "SHIFT_JIS" "\0" "ARMSCII-8" "\0" "ARMSCII-8" "\0" "PT154" "\0" "PT154" "\0" /*"ISCII-DEV" "\0" "?" "\0"*/ "*" "\0" "UTF-8" "\0"; # endif # if defined VMS /* To avoid the troubles of an extra file charset.alias_vms in the sources of many GNU packages, simply inline the aliases here. */ /* The list of encodings is taken from the OpenVMS 7.3-1 documentation "Compaq C Run-Time Library Reference Manual for OpenVMS systems" section 10.7 "Handling Different Character Sets". */ cp = "ISO8859-1" "\0" "ISO-8859-1" "\0" "ISO8859-2" "\0" "ISO-8859-2" "\0" "ISO8859-5" "\0" "ISO-8859-5" "\0" "ISO8859-7" "\0" "ISO-8859-7" "\0" "ISO8859-8" "\0" "ISO-8859-8" "\0" "ISO8859-9" "\0" "ISO-8859-9" "\0" /* Japanese */ "eucJP" "\0" "EUC-JP" "\0" "SJIS" "\0" "SHIFT_JIS" "\0" "DECKANJI" "\0" "DEC-KANJI" "\0" "SDECKANJI" "\0" "EUC-JP" "\0" /* Chinese */ "eucTW" "\0" "EUC-TW" "\0" "DECHANYU" "\0" "DEC-HANYU" "\0" "DECHANZI" "\0" "GB2312" "\0" /* Korean */ "DECKOREAN" "\0" "EUC-KR" "\0"; # endif # if defined WIN32_NATIVE || defined __CYGWIN__ /* To avoid the troubles of installing a separate file in the same directory as the DLL and of retrieving the DLL's directory at runtime, simply inline the aliases here. */ cp = "CP936" "\0" "GBK" "\0" "CP1361" "\0" "JOHAB" "\0" "CP20127" "\0" "ASCII" "\0" "CP20866" "\0" "KOI8-R" "\0" "CP20936" "\0" "GB2312" "\0" "CP21866" "\0" "KOI8-RU" "\0" "CP28591" "\0" "ISO-8859-1" "\0" "CP28592" "\0" "ISO-8859-2" "\0" "CP28593" "\0" "ISO-8859-3" "\0" "CP28594" "\0" "ISO-8859-4" "\0" "CP28595" "\0" "ISO-8859-5" "\0" "CP28596" "\0" "ISO-8859-6" "\0" "CP28597" "\0" "ISO-8859-7" "\0" "CP28598" "\0" "ISO-8859-8" "\0" "CP28599" "\0" "ISO-8859-9" "\0" "CP28605" "\0" "ISO-8859-15" "\0" "CP38598" "\0" "ISO-8859-8" "\0" "CP51932" "\0" "EUC-JP" "\0" "CP51936" "\0" "GB2312" "\0" "CP51949" "\0" "EUC-KR" "\0" "CP51950" "\0" "EUC-TW" "\0" "CP54936" "\0" "GB18030" "\0" "CP65001" "\0" "UTF-8" "\0"; # endif #endif charset_aliases = cp; } return cp; } /* Determine the current locale's character encoding, and canonicalize it into one of the canonical names listed in config.charset. The result must not be freed; it is statically allocated. If the canonical name cannot be determined, the result is a non-canonical name. */ #ifdef STATIC STATIC #endif const char * locale_charset (void) { const char *codeset; const char *aliases; #if !(defined WIN32_NATIVE || defined OS2) # if HAVE_LANGINFO_CODESET /* Most systems support nl_langinfo (CODESET) nowadays. */ codeset = nl_langinfo (CODESET); # ifdef __CYGWIN__ /* Cygwin 2006 does not have locales. nl_langinfo (CODESET) always returns "US-ASCII". As long as this is not fixed, return the suffix of the locale name from the environment variables (if present) or the codepage as a number. */ if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0) { const char *locale; static char buf[2 + 10 + 1]; locale = getenv ("LC_ALL"); if (locale == NULL || locale[0] == '\0') { locale = getenv ("LC_CTYPE"); if (locale == NULL || locale[0] == '\0') locale = getenv ("LANG"); } if (locale != NULL && locale[0] != '\0') { /* If the locale name contains an encoding after the dot, return it. */ const char *dot = strchr (locale, '.'); if (dot != NULL) { const char *modifier; dot++; /* Look for the possible @... trailer and remove it, if any. */ modifier = strchr (dot, '@'); if (modifier == NULL) return dot; if (modifier - dot < sizeof (buf)) { memcpy (buf, dot, modifier - dot); buf [modifier - dot] = '\0'; return buf; } } } /* Woe32 has a function returning the locale's codepage as a number. */ sprintf (buf, "CP%u", GetACP ()); codeset = buf; } # endif # else /* On old systems which lack it, use setlocale or getenv. */ const char *locale = NULL; /* But most old systems don't have a complete set of locales. Some (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't use setlocale here; it would return "C" when it doesn't support the locale name the user has set. */ # if 0 locale = setlocale (LC_CTYPE, NULL); # endif if (locale == NULL || locale[0] == '\0') { locale = getenv ("LC_ALL"); if (locale == NULL || locale[0] == '\0') { locale = getenv ("LC_CTYPE"); if (locale == NULL || locale[0] == '\0') locale = getenv ("LANG"); } } /* On some old systems, one used to set locale = "iso8859_1". On others, you set it to "language_COUNTRY.charset". In any case, we resolve it through the charset.alias file. */ codeset = locale; # endif #elif defined WIN32_NATIVE static char buf[2 + 10 + 1]; /* Woe32 has a function returning the locale's codepage as a number. When the output goes to a console window, in Windows 95, it would have been appropriate to use GetOEMCP() instead of GetACP(). But this has been corrected: In Windows XP SP3, consoles accept output in the GetACP() encoding. The GetConsoleOutputCP() function still returns the same as GetOEMCP() (not GetACP()!), but the font handling in the console actually uses the GetACP() encoding. If you want to "correct" this by calling SetConsoleOutputCP(GetACP()), then for a TrueType font it has no visible effect on the displayed glyphs, whereas when a raster font is in use, the console performs an extra conversion from GetOEMCP() to GetACP() encoding, thus changing the effective codepage of the console from GetACP() to GetOEMCP()! In summary, GetConsoleOutputCP() and SetConsoleOutputCP() are now completely broken. */ sprintf (buf, "CP%u", GetACP ()); codeset = buf; #elif defined OS2 const char *locale; static char buf[2 + 10 + 1]; ULONG cp[3]; ULONG cplen; /* Allow user to override the codeset, as set in the operating system, with standard language environment variables. */ locale = getenv ("LC_ALL"); if (locale == NULL || locale[0] == '\0') { locale = getenv ("LC_CTYPE"); if (locale == NULL || locale[0] == '\0') locale = getenv ("LANG"); } if (locale != NULL && locale[0] != '\0') { /* If the locale name contains an encoding after the dot, return it. */ const char *dot = strchr (locale, '.'); if (dot != NULL) { const char *modifier; dot++; /* Look for the possible @... trailer and remove it, if any. */ modifier = strchr (dot, '@'); if (modifier == NULL) return dot; if (modifier - dot < sizeof (buf)) { memcpy (buf, dot, modifier - dot); buf [modifier - dot] = '\0'; return buf; } } /* Resolve through the charset.alias file. */ codeset = locale; } else { /* OS/2 has a function returning the locale's codepage as a number. */ if (DosQueryCp (sizeof (cp), cp, &cplen)) codeset = ""; else { sprintf (buf, "CP%u", cp[0]); codeset = buf; } } #endif if (codeset == NULL) /* The canonical name cannot be determined. */ codeset = ""; /* Resolve alias. */ for (aliases = get_charset_aliases (); *aliases != '\0'; aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1) if (strcmp (codeset, aliases) == 0 || (aliases[0] == '*' && aliases[1] == '\0')) { codeset = aliases + strlen (aliases) + 1; break; } /* Don't return an empty string. GNU libc and GNU libiconv interpret the empty string as denoting "the locale's character encoding", thus GNU libiconv would call this function a second time. */ if (codeset[0] == '\0') codeset = "ASCII"; return codeset; }