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, 2008-2010 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; 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 < 1.7 does not have locales. nl_langinfo (CODESET) always returns "US-ASCII". 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: GetACP(). This encoding is used by Cygwin, unless the user has set the environment variable CYGWIN=codepage:oem (which very few people do). Output directed to console windows needs to be converted (to GetOEMCP() if the console is using a raster font, or to GetConsoleOutputCP() if it is using a TrueType font). Cygwin does this conversion transparently (see winsup/cygwin/fhandler_console.cc), converting to GetConsoleOutputCP(). This leads to correct results, except when SetConsoleOutputCP has been called and a raster font is in use. */ 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: GetACP(). When the output goes to a console window, it needs to be provided in GetOEMCP() encoding if the console is using a raster font, or in GetConsoleOutputCP() encoding if it is using a TrueType font. But in GUI programs and for output sent to files and pipes, GetACP() encoding is the best bet. */ 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; }