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/* Determine a canonical name for the current locale's character encoding.
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Copyright (C) 2000-2006, 2008-2012 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, see <http://www.gnu.org/licenses/>. */
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/* Written by Bruno Haible <bruno@clisp.org>. */
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#include "localcharset.h"
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#if defined __APPLE__ && defined __MACH__ && HAVE_LANGINFO_CODESET
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# define DARWIN7 /* Darwin 7 or newer, i.e. MacOS X 10.3 or newer */
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#if defined _WIN32 || defined __WIN32__
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# define WINDOWS_NATIVE
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/* Assume EMX program runs on OS/2, even if compiled under DOS. */
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#if !defined WINDOWS_NATIVE
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# if HAVE_LANGINFO_CODESET
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# include <langinfo.h>
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# if 0 /* see comment below */
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# define WIN32_LEAN_AND_MEAN
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#elif defined WINDOWS_NATIVE
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# define WIN32_LEAN_AND_MEAN
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#if ENABLE_RELOCATABLE
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# include "relocatable.h"
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# define relocate(pathname) (pathname)
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# include "configmake.h"
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/* Define O_NOFOLLOW to 0 on platforms where it does not exist. */
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#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
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/* Native Windows, Cygwin, OS/2, DOS */
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# define ISSLASH(C) ((C) == '/' || (C) == '\\')
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#ifndef DIRECTORY_SEPARATOR
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# define DIRECTORY_SEPARATOR '/'
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# define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
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#if HAVE_DECL_GETC_UNLOCKED
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# define getc getc_unlocked
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/* The following static variable is declared 'volatile' to avoid a
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possible multithread problem in the function get_charset_aliases. If we
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are running in a threaded environment, and if two threads initialize
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'charset_aliases' simultaneously, both will produce the same value,
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and everything will be ok if the two assignments to 'charset_aliases'
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are atomic. But I don't know what will happen if the two assignments mix. */
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# define volatile /* empty */
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/* Pointer to the contents of the charset.alias file, if it has already been
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read, else NULL. Its format is:
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ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */
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static const char * volatile charset_aliases;
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/* Return a pointer to the contents of the charset.alias file. */
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get_charset_aliases (void)
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cp = charset_aliases;
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#if !(defined DARWIN7 || defined VMS || defined WINDOWS_NATIVE || defined __CYGWIN__)
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const char *base = "charset.alias";
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/* Make it possible to override the charset.alias location. This is
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necessary for running the testsuite before "make install". */
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dir = getenv ("CHARSETALIASDIR");
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if (dir == NULL || dir[0] == '\0')
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dir = relocate (LIBDIR);
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/* Concatenate dir and base into freshly allocated file_name. */
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size_t dir_len = strlen (dir);
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size_t base_len = strlen (base);
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int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1]));
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file_name = (char *) malloc (dir_len + add_slash + base_len + 1);
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if (file_name != NULL)
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memcpy (file_name, dir, dir_len);
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file_name[dir_len] = DIRECTORY_SEPARATOR;
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memcpy (file_name + dir_len + add_slash, base, base_len + 1);
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if (file_name == NULL)
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/* Out of memory. Treat the file as empty. */
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/* Open the file. Reject symbolic links on platforms that support
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O_NOFOLLOW. This is a security feature. Without it, an attacker
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could retrieve parts of the contents (namely, the tail of the
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first line that starts with "* ") of an arbitrary file by placing
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a symbolic link to that file under the name "charset.alias" in
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some writable directory and defining the environment variable
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CHARSETALIASDIR to point to that directory. */
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fd = open (file_name,
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O_RDONLY | (HAVE_WORKING_O_NOFOLLOW ? O_NOFOLLOW : 0));
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/* File not found. Treat it as empty. */
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fp = fdopen (fd, "r");
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/* Out of memory. Treat the file as empty. */
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/* Parse the file's contents. */
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char *res_ptr = NULL;
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if (c == '\n' || c == ' ' || c == '\t')
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/* Skip comment, to end of line. */
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while (!(c == EOF || c == '\n'));
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if (fscanf (fp, "%50s %50s", buf1, buf2) < 2)
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old_res_ptr = res_ptr;
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res_size = l1 + 1 + l2 + 1;
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res_ptr = (char *) malloc (res_size + 1);
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res_size += l1 + 1 + l2 + 1;
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res_ptr = (char *) realloc (res_ptr, res_size + 1);
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strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1);
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strcpy (res_ptr + res_size - (l2 + 1), buf2);
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*(res_ptr + res_size) = '\0';
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/* To avoid the trouble of installing a file that is shared by many
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GNU packages -- many packaging systems have problems with this --,
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simply inline the aliases here. */
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cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
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"ISO8859-2" "\0" "ISO-8859-2" "\0"
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"ISO8859-4" "\0" "ISO-8859-4" "\0"
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"ISO8859-5" "\0" "ISO-8859-5" "\0"
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"ISO8859-7" "\0" "ISO-8859-7" "\0"
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"ISO8859-9" "\0" "ISO-8859-9" "\0"
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"ISO8859-13" "\0" "ISO-8859-13" "\0"
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"ISO8859-15" "\0" "ISO-8859-15" "\0"
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"KOI8-R" "\0" "KOI8-R" "\0"
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"KOI8-U" "\0" "KOI8-U" "\0"
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"CP866" "\0" "CP866" "\0"
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"CP949" "\0" "CP949" "\0"
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"CP1131" "\0" "CP1131" "\0"
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"CP1251" "\0" "CP1251" "\0"
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"eucCN" "\0" "GB2312" "\0"
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"GB2312" "\0" "GB2312" "\0"
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"eucJP" "\0" "EUC-JP" "\0"
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"eucKR" "\0" "EUC-KR" "\0"
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"Big5" "\0" "BIG5" "\0"
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"Big5HKSCS" "\0" "BIG5-HKSCS" "\0"
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"GBK" "\0" "GBK" "\0"
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"GB18030" "\0" "GB18030" "\0"
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"SJIS" "\0" "SHIFT_JIS" "\0"
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"ARMSCII-8" "\0" "ARMSCII-8" "\0"
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"PT154" "\0" "PT154" "\0"
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/*"ISCII-DEV" "\0" "?" "\0"*/
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"*" "\0" "UTF-8" "\0";
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/* To avoid the troubles of an extra file charset.alias_vms in the
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sources of many GNU packages, simply inline the aliases here. */
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/* The list of encodings is taken from the OpenVMS 7.3-1 documentation
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"Compaq C Run-Time Library Reference Manual for OpenVMS systems"
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section 10.7 "Handling Different Character Sets". */
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cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
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"ISO8859-2" "\0" "ISO-8859-2" "\0"
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"ISO8859-5" "\0" "ISO-8859-5" "\0"
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"ISO8859-7" "\0" "ISO-8859-7" "\0"
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"ISO8859-8" "\0" "ISO-8859-8" "\0"
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"ISO8859-9" "\0" "ISO-8859-9" "\0"
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"eucJP" "\0" "EUC-JP" "\0"
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"SJIS" "\0" "SHIFT_JIS" "\0"
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"DECKANJI" "\0" "DEC-KANJI" "\0"
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"SDECKANJI" "\0" "EUC-JP" "\0"
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"eucTW" "\0" "EUC-TW" "\0"
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"DECHANYU" "\0" "DEC-HANYU" "\0"
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"DECHANZI" "\0" "GB2312" "\0"
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"DECKOREAN" "\0" "EUC-KR" "\0";
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# if defined WINDOWS_NATIVE || defined __CYGWIN__
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/* To avoid the troubles of installing a separate file in the same
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directory as the DLL and of retrieving the DLL's directory at
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runtime, simply inline the aliases here. */
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cp = "CP936" "\0" "GBK" "\0"
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"CP1361" "\0" "JOHAB" "\0"
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"CP20127" "\0" "ASCII" "\0"
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"CP20866" "\0" "KOI8-R" "\0"
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"CP20936" "\0" "GB2312" "\0"
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"CP21866" "\0" "KOI8-RU" "\0"
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"CP28591" "\0" "ISO-8859-1" "\0"
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"CP28592" "\0" "ISO-8859-2" "\0"
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"CP28593" "\0" "ISO-8859-3" "\0"
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"CP28594" "\0" "ISO-8859-4" "\0"
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"CP28595" "\0" "ISO-8859-5" "\0"
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"CP28596" "\0" "ISO-8859-6" "\0"
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"CP28597" "\0" "ISO-8859-7" "\0"
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"CP28598" "\0" "ISO-8859-8" "\0"
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"CP28599" "\0" "ISO-8859-9" "\0"
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"CP28605" "\0" "ISO-8859-15" "\0"
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"CP38598" "\0" "ISO-8859-8" "\0"
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"CP51932" "\0" "EUC-JP" "\0"
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"CP51936" "\0" "GB2312" "\0"
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"CP51949" "\0" "EUC-KR" "\0"
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"CP51950" "\0" "EUC-TW" "\0"
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"CP54936" "\0" "GB18030" "\0"
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"CP65001" "\0" "UTF-8" "\0";
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charset_aliases = cp;
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/* Determine the current locale's character encoding, and canonicalize it
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into one of the canonical names listed in config.charset.
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The result must not be freed; it is statically allocated.
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If the canonical name cannot be determined, the result is a non-canonical
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locale_charset (void)
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#if !(defined WINDOWS_NATIVE || defined OS2)
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# if HAVE_LANGINFO_CODESET
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/* Most systems support nl_langinfo (CODESET) nowadays. */
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codeset = nl_langinfo (CODESET);
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/* Cygwin < 1.7 does not have locales. nl_langinfo (CODESET) always
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returns "US-ASCII". Return the suffix of the locale name from the
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environment variables (if present) or the codepage as a number. */
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if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0)
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static char buf[2 + 10 + 1];
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locale = getenv ("LC_ALL");
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LC_CTYPE");
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LANG");
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if (locale != NULL && locale[0] != '\0')
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/* If the locale name contains an encoding after the dot, return
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const char *dot = strchr (locale, '.');
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const char *modifier;
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/* Look for the possible @... trailer and remove it, if any. */
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modifier = strchr (dot, '@');
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if (modifier == NULL)
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if (modifier - dot < sizeof (buf))
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memcpy (buf, dot, modifier - dot);
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buf [modifier - dot] = '\0';
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/* The Windows API has a function returning the locale's codepage as a
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number: GetACP(). This encoding is used by Cygwin, unless the user
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has set the environment variable CYGWIN=codepage:oem (which very few
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Output directed to console windows needs to be converted (to
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GetOEMCP() if the console is using a raster font, or to
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GetConsoleOutputCP() if it is using a TrueType font). Cygwin does
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this conversion transparently (see winsup/cygwin/fhandler_console.cc),
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converting to GetConsoleOutputCP(). This leads to correct results,
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except when SetConsoleOutputCP has been called and a raster font is
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sprintf (buf, "CP%u", GetACP ());
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/* On old systems which lack it, use setlocale or getenv. */
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const char *locale = NULL;
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/* But most old systems don't have a complete set of locales. Some
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(like SunOS 4 or DJGPP) have only the C locale. Therefore we don't
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use setlocale here; it would return "C" when it doesn't support the
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locale name the user has set. */
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locale = setlocale (LC_CTYPE, NULL);
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LC_ALL");
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LC_CTYPE");
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LANG");
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/* On some old systems, one used to set locale = "iso8859_1". On others,
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you set it to "language_COUNTRY.charset". In any case, we resolve it
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through the charset.alias file. */
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#elif defined WINDOWS_NATIVE
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static char buf[2 + 10 + 1];
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/* The Windows API has a function returning the locale's codepage as a
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When the output goes to a console window, it needs to be provided in
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GetOEMCP() encoding if the console is using a raster font, or in
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GetConsoleOutputCP() encoding if it is using a TrueType font.
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But in GUI programs and for output sent to files and pipes, GetACP()
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encoding is the best bet. */
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sprintf (buf, "CP%u", GetACP ());
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static char buf[2 + 10 + 1];
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/* Allow user to override the codeset, as set in the operating system,
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with standard language environment variables. */
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locale = getenv ("LC_ALL");
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LC_CTYPE");
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if (locale == NULL || locale[0] == '\0')
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locale = getenv ("LANG");
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if (locale != NULL && locale[0] != '\0')
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/* If the locale name contains an encoding after the dot, return it. */
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const char *dot = strchr (locale, '.');
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const char *modifier;
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/* Look for the possible @... trailer and remove it, if any. */
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modifier = strchr (dot, '@');
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if (modifier == NULL)
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if (modifier - dot < sizeof (buf))
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memcpy (buf, dot, modifier - dot);
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buf [modifier - dot] = '\0';
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/* Resolve through the charset.alias file. */
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/* OS/2 has a function returning the locale's codepage as a number. */
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if (DosQueryCp (sizeof (cp), cp, &cplen))
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sprintf (buf, "CP%u", cp[0]);
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/* The canonical name cannot be determined. */
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for (aliases = get_charset_aliases ();
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aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1)
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if (strcmp (codeset, aliases) == 0
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|| (aliases[0] == '*' && aliases[1] == '\0'))
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codeset = aliases + strlen (aliases) + 1;
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/* Don't return an empty string. GNU libc and GNU libiconv interpret
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the empty string as denoting "the locale's character encoding",
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thus GNU libiconv would call this function a second time. */
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if (codeset[0] == '\0')
added
removed
lib/localcharset.c
