| 1 | /* Determine a canonical name for the current locale's character encoding. | 
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| 2 |  | 
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| 3 | Copyright (C) 2000-2003 Free Software Foundation, Inc. | 
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| 4 |  | 
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| 5 | This program is free software; you can redistribute it and/or modify it | 
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| 6 | under the terms of the GNU Library General Public License as published | 
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| 7 | by the Free Software Foundation; either version 2, or (at your option) | 
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| 8 | any later version. | 
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| 9 |  | 
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| 10 | This program is distributed in the hope that it will be useful, | 
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU | 
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| 13 | Library General Public License for more details. | 
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| 14 |  | 
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| 15 | You should have received a copy of the GNU Library General Public | 
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| 16 | License along with this program; if not, write to the Free Software | 
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| 17 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, | 
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| 18 | USA.  */ | 
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| 19 |  | 
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| 20 | /* Written by Bruno Haible <bruno@clisp.org>.  */ | 
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| 21 |  | 
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| 22 | #ifdef HAVE_CONFIG_H | 
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| 23 | # include <config.h> | 
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| 24 | #endif | 
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| 25 |  | 
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| 26 | /* Specification.  */ | 
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| 27 | #include "localcharset.h" | 
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| 28 |  | 
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| 29 | #if HAVE_STDDEF_H | 
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| 30 | # include <stddef.h> | 
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| 31 | #endif | 
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| 32 |  | 
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| 33 | #include <stdio.h> | 
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| 34 | #if HAVE_STRING_H | 
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| 35 | # include <string.h> | 
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| 36 | #else | 
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| 37 | # include <strings.h> | 
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| 38 | #endif | 
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| 39 | #if HAVE_STDLIB_H | 
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| 40 | # include <stdlib.h> | 
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| 41 | #endif | 
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| 42 |  | 
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| 43 | #if defined _WIN32 || defined __WIN32__ | 
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| 44 | # undef WIN32   /* avoid warning on mingw32 */ | 
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| 45 | # define WIN32 | 
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| 46 | #endif | 
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| 47 |  | 
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| 48 | #if defined __EMX__ | 
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| 49 | /* Assume EMX program runs on OS/2, even if compiled under DOS.  */ | 
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| 50 | # define OS2 | 
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| 51 | #endif | 
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| 52 |  | 
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| 53 | #if !defined WIN32 | 
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| 54 | # if HAVE_LANGINFO_CODESET | 
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| 55 | #  include <langinfo.h> | 
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| 56 | # else | 
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| 57 | #  if HAVE_SETLOCALE | 
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| 58 | #   include <locale.h> | 
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| 59 | #  endif | 
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| 60 | # endif | 
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| 61 | #elif defined WIN32 | 
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| 62 | # define WIN32_LEAN_AND_MEAN | 
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| 63 | # include <windows.h> | 
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| 64 | #endif | 
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| 65 | #if defined OS2 | 
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| 66 | # define INCL_DOS | 
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| 67 | # include <os2.h> | 
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| 68 | #endif | 
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| 69 |  | 
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| 70 | #if ENABLE_RELOCATABLE | 
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| 71 | # include "relocatable.h" | 
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| 72 | #else | 
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| 73 | # define relocate(pathname) (pathname) | 
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| 74 | #endif | 
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| 75 |  | 
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| 76 | #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__ | 
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| 77 | /* Win32, OS/2, DOS */ | 
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| 78 | # define ISSLASH(C) ((C) == '/' || (C) == '\\') | 
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| 79 | #endif | 
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| 80 |  | 
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| 81 | #ifndef DIRECTORY_SEPARATOR | 
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| 82 | # define DIRECTORY_SEPARATOR '/' | 
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| 83 | #endif | 
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| 84 |  | 
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| 85 | #ifndef ISSLASH | 
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| 86 | # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR) | 
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| 87 | #endif | 
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| 88 |  | 
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| 89 | #if HAVE_DECL_GETC_UNLOCKED | 
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| 90 | # undef getc | 
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| 91 | # define getc getc_unlocked | 
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| 92 | #endif | 
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| 93 |  | 
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| 94 | /* The following static variable is declared 'volatile' to avoid a | 
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| 95 | possible multithread problem in the function get_charset_aliases. If we | 
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| 96 | are running in a threaded environment, and if two threads initialize | 
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| 97 | 'charset_aliases' simultaneously, both will produce the same value, | 
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| 98 | and everything will be ok if the two assignments to 'charset_aliases' | 
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| 99 | are atomic. But I don't know what will happen if the two assignments mix.  */ | 
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| 100 | #if __STDC__ != 1 | 
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| 101 | # define volatile /* empty */ | 
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| 102 | #endif | 
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| 103 | /* Pointer to the contents of the charset.alias file, if it has already been | 
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| 104 | read, else NULL.  Its format is: | 
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| 105 | ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0'  */ | 
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| 106 | static const char * volatile charset_aliases; | 
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| 107 |  | 
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| 108 | /* Return a pointer to the contents of the charset.alias file.  */ | 
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| 109 | static const char * | 
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| 110 | get_charset_aliases () | 
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| 111 | { | 
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| 112 | const char *cp; | 
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| 113 |  | 
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| 114 | cp = charset_aliases; | 
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| 115 | if (cp == NULL) | 
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| 116 | { | 
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| 117 | #if !(defined VMS || defined WIN32) | 
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| 118 | FILE *fp; | 
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| 119 | const char *dir = relocate (LIBDIR); | 
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| 120 | const char *base = "charset.alias"; | 
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| 121 | char *file_name; | 
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| 122 |  | 
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| 123 | /* Concatenate dir and base into freshly allocated file_name.  */ | 
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| 124 | { | 
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| 125 | size_t dir_len = strlen (dir); | 
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| 126 | size_t base_len = strlen (base); | 
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| 127 | int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1])); | 
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| 128 | file_name = (char *) malloc (dir_len + add_slash + base_len + 1); | 
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| 129 | if (file_name != NULL) | 
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| 130 | { | 
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| 131 | memcpy (file_name, dir, dir_len); | 
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| 132 | if (add_slash) | 
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| 133 | file_name[dir_len] = DIRECTORY_SEPARATOR; | 
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| 134 | memcpy (file_name + dir_len + add_slash, base, base_len + 1); | 
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| 135 | } | 
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| 136 | } | 
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| 137 |  | 
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| 138 | if (file_name == NULL || (fp = fopen (file_name, "r")) == NULL) | 
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| 139 | /* Out of memory or file not found, treat it as empty.  */ | 
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| 140 | cp = ""; | 
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| 141 | else | 
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| 142 | { | 
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| 143 | /* Parse the file's contents.  */ | 
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| 144 | int c; | 
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| 145 | char buf1[50+1]; | 
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| 146 | char buf2[50+1]; | 
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| 147 | char *res_ptr = NULL; | 
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| 148 | size_t res_size = 0; | 
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| 149 | size_t l1, l2; | 
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| 150 |  | 
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| 151 | for (;;) | 
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| 152 | { | 
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| 153 | c = getc (fp); | 
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| 154 | if (c == EOF) | 
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| 155 | break; | 
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| 156 | if (c == '\n' || c == ' ' || c == '\t') | 
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| 157 | continue; | 
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| 158 | if (c == '#') | 
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| 159 | { | 
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| 160 | /* Skip comment, to end of line.  */ | 
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| 161 | do | 
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| 162 | c = getc (fp); | 
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| 163 | while (!(c == EOF || c == '\n')); | 
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| 164 | if (c == EOF) | 
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| 165 | break; | 
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| 166 | continue; | 
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| 167 | } | 
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| 168 | ungetc (c, fp); | 
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| 169 | if (fscanf (fp, "%50s %50s", buf1, buf2) < 2) | 
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| 170 | break; | 
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| 171 | l1 = strlen (buf1); | 
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| 172 | l2 = strlen (buf2); | 
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| 173 | if (res_size == 0) | 
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| 174 | { | 
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| 175 | res_size = l1 + 1 + l2 + 1; | 
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| 176 | res_ptr = (char *) malloc (res_size + 1); | 
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| 177 | } | 
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| 178 | else | 
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| 179 | { | 
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| 180 | res_size += l1 + 1 + l2 + 1; | 
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| 181 | res_ptr = (char *) realloc (res_ptr, res_size + 1); | 
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| 182 | } | 
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| 183 | if (res_ptr == NULL) | 
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| 184 | { | 
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| 185 | /* Out of memory. */ | 
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| 186 | res_size = 0; | 
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| 187 | break; | 
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| 188 | } | 
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| 189 | strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1); | 
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| 190 | strcpy (res_ptr + res_size - (l2 + 1), buf2); | 
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| 191 | } | 
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| 192 | fclose (fp); | 
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| 193 | if (res_size == 0) | 
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| 194 | cp = ""; | 
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| 195 | else | 
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| 196 | { | 
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| 197 | *(res_ptr + res_size) = '\0'; | 
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| 198 | cp = res_ptr; | 
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| 199 | } | 
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| 200 | } | 
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| 201 |  | 
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| 202 | if (file_name != NULL) | 
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| 203 | free (file_name); | 
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| 204 |  | 
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| 205 | #else | 
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| 206 |  | 
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| 207 | # if defined VMS | 
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| 208 | /* To avoid the troubles of an extra file charset.alias_vms in the | 
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| 209 | sources of many GNU packages, simply inline the aliases here.  */ | 
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| 210 | /* The list of encodings is taken from the OpenVMS 7.3-1 documentation | 
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| 211 | "Compaq C Run-Time Library Reference Manual for OpenVMS systems" | 
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| 212 | section 10.7 "Handling Different Character Sets".  */ | 
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| 213 | cp = "ISO8859-1" "\0" "ISO-8859-1" "\0" | 
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| 214 | "ISO8859-2" "\0" "ISO-8859-2" "\0" | 
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| 215 | "ISO8859-5" "\0" "ISO-8859-5" "\0" | 
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| 216 | "ISO8859-7" "\0" "ISO-8859-7" "\0" | 
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| 217 | "ISO8859-8" "\0" "ISO-8859-8" "\0" | 
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| 218 | "ISO8859-9" "\0" "ISO-8859-9" "\0" | 
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| 219 | /* Japanese */ | 
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| 220 | "eucJP" "\0" "EUC-JP" "\0" | 
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| 221 | "SJIS" "\0" "SHIFT_JIS" "\0" | 
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| 222 | "DECKANJI" "\0" "DEC-KANJI" "\0" | 
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| 223 | "SDECKANJI" "\0" "EUC-JP" "\0" | 
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| 224 | /* Chinese */ | 
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| 225 | "eucTW" "\0" "EUC-TW" "\0" | 
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| 226 | "DECHANYU" "\0" "DEC-HANYU" "\0" | 
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| 227 | "DECHANZI" "\0" "GB2312" "\0" | 
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| 228 | /* Korean */ | 
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| 229 | "DECKOREAN" "\0" "EUC-KR" "\0"; | 
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| 230 | # endif | 
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| 231 |  | 
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| 232 | # if defined WIN32 | 
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| 233 | /* To avoid the troubles of installing a separate file in the same | 
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| 234 | directory as the DLL and of retrieving the DLL's directory at | 
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| 235 | runtime, simply inline the aliases here.  */ | 
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| 236 |  | 
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| 237 | cp = "CP936" "\0" "GBK" "\0" | 
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| 238 | "CP1361" "\0" "JOHAB" "\0" | 
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| 239 | "CP20127" "\0" "ASCII" "\0" | 
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| 240 | "CP20866" "\0" "KOI8-R" "\0" | 
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| 241 | "CP21866" "\0" "KOI8-RU" "\0" | 
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| 242 | "CP28591" "\0" "ISO-8859-1" "\0" | 
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| 243 | "CP28592" "\0" "ISO-8859-2" "\0" | 
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| 244 | "CP28593" "\0" "ISO-8859-3" "\0" | 
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| 245 | "CP28594" "\0" "ISO-8859-4" "\0" | 
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| 246 | "CP28595" "\0" "ISO-8859-5" "\0" | 
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| 247 | "CP28596" "\0" "ISO-8859-6" "\0" | 
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| 248 | "CP28597" "\0" "ISO-8859-7" "\0" | 
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| 249 | "CP28598" "\0" "ISO-8859-8" "\0" | 
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| 250 | "CP28599" "\0" "ISO-8859-9" "\0" | 
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| 251 | "CP28605" "\0" "ISO-8859-15" "\0"; | 
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| 252 | # endif | 
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| 253 | #endif | 
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| 254 |  | 
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| 255 | charset_aliases = cp; | 
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| 256 | } | 
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| 257 |  | 
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| 258 | return cp; | 
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| 259 | } | 
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| 260 |  | 
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| 261 | /* Determine the current locale's character encoding, and canonicalize it | 
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| 262 | into one of the canonical names listed in config.charset. | 
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| 263 | The result must not be freed; it is statically allocated. | 
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| 264 | If the canonical name cannot be determined, the result is a non-canonical | 
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| 265 | name.  */ | 
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| 266 |  | 
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| 267 | #ifdef STATIC | 
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| 268 | STATIC | 
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| 269 | #endif | 
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| 270 | const char * | 
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| 271 | locale_charset () | 
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| 272 | { | 
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| 273 | const char *codeset; | 
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| 274 | const char *aliases; | 
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| 275 |  | 
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| 276 | #if !(defined WIN32 || defined OS2) | 
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| 277 |  | 
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| 278 | # if HAVE_LANGINFO_CODESET | 
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| 279 |  | 
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| 280 | /* Most systems support nl_langinfo (CODESET) nowadays.  */ | 
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| 281 | codeset = nl_langinfo (CODESET); | 
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| 282 |  | 
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| 283 | # else | 
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| 284 |  | 
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| 285 | /* On old systems which lack it, use setlocale or getenv.  */ | 
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| 286 | const char *locale = NULL; | 
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| 287 |  | 
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| 288 | /* But most old systems don't have a complete set of locales.  Some | 
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| 289 | (like SunOS 4 or DJGPP) have only the C locale.  Therefore we don't | 
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| 290 | use setlocale here; it would return "C" when it doesn't support the | 
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| 291 | locale name the user has set.  */ | 
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| 292 | #  if HAVE_SETLOCALE && 0 | 
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| 293 | locale = setlocale (LC_CTYPE, NULL); | 
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| 294 | #  endif | 
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| 295 | if (locale == NULL || locale[0] == '\0') | 
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| 296 | { | 
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| 297 | locale = getenv ("LC_ALL"); | 
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| 298 | if (locale == NULL || locale[0] == '\0') | 
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| 299 | { | 
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| 300 | locale = getenv ("LC_CTYPE"); | 
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| 301 | if (locale == NULL || locale[0] == '\0') | 
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| 302 | locale = getenv ("LANG"); | 
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| 303 | } | 
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| 304 | } | 
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| 305 |  | 
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| 306 | /* On some old systems, one used to set locale = "iso8859_1". On others, | 
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| 307 | you set it to "language_COUNTRY.charset". In any case, we resolve it | 
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| 308 | through the charset.alias file.  */ | 
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| 309 | codeset = locale; | 
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| 310 |  | 
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| 311 | # endif | 
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| 312 |  | 
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| 313 | #elif defined WIN32 | 
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| 314 |  | 
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| 315 | static char buf[2 + 10 + 1]; | 
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| 316 |  | 
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| 317 | /* Woe32 has a function returning the locale's codepage as a number.  */ | 
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| 318 | sprintf (buf, "CP%u", GetACP ()); | 
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| 319 | codeset = buf; | 
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| 320 |  | 
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| 321 | #elif defined OS2 | 
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| 322 |  | 
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| 323 | const char *locale; | 
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| 324 | static char buf[2 + 10 + 1]; | 
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| 325 | ULONG cp[3]; | 
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| 326 | ULONG cplen; | 
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| 327 |  | 
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| 328 | /* Allow user to override the codeset, as set in the operating system, | 
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| 329 | with standard language environment variables.  */ | 
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| 330 | locale = getenv ("LC_ALL"); | 
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| 331 | if (locale == NULL || locale[0] == '\0') | 
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| 332 | { | 
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| 333 | locale = getenv ("LC_CTYPE"); | 
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| 334 | if (locale == NULL || locale[0] == '\0') | 
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| 335 | locale = getenv ("LANG"); | 
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| 336 | } | 
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| 337 | if (locale != NULL && locale[0] != '\0') | 
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| 338 | { | 
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| 339 | /* If the locale name contains an encoding after the dot, return it.  */ | 
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| 340 | const char *dot = strchr (locale, '.'); | 
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| 341 |  | 
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| 342 | if (dot != NULL) | 
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| 343 | { | 
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| 344 | const char *modifier; | 
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| 345 |  | 
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| 346 | dot++; | 
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| 347 | /* Look for the possible @... trailer and remove it, if any.  */ | 
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| 348 | modifier = strchr (dot, '@'); | 
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| 349 | if (modifier == NULL) | 
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| 350 | return dot; | 
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| 351 | if (modifier - dot < sizeof (buf)) | 
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| 352 | { | 
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| 353 | memcpy (buf, dot, modifier - dot); | 
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| 354 | buf [modifier - dot] = '\0'; | 
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| 355 | return buf; | 
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| 356 | } | 
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| 357 | } | 
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| 358 |  | 
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| 359 | /* Resolve through the charset.alias file.  */ | 
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| 360 | codeset = locale; | 
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| 361 | } | 
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| 362 | else | 
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| 363 | { | 
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| 364 | /* OS/2 has a function returning the locale's codepage as a number.  */ | 
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| 365 | if (DosQueryCp (sizeof (cp), cp, &cplen)) | 
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| 366 | codeset = ""; | 
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| 367 | else | 
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| 368 | { | 
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| 369 | sprintf (buf, "CP%u", cp[0]); | 
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| 370 | codeset = buf; | 
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| 371 | } | 
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| 372 | } | 
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| 373 |  | 
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| 374 | #endif | 
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| 375 |  | 
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| 376 | if (codeset == NULL) | 
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| 377 | /* The canonical name cannot be determined.  */ | 
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| 378 | codeset = ""; | 
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| 379 |  | 
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| 380 | /* Resolve alias. */ | 
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| 381 | for (aliases = get_charset_aliases (); | 
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| 382 | *aliases != '\0'; | 
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| 383 | aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1) | 
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| 384 | if (strcmp (codeset, aliases) == 0 | 
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| 385 | || (aliases[0] == '*' && aliases[1] == '\0')) | 
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| 386 | { | 
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| 387 | codeset = aliases + strlen (aliases) + 1; | 
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| 388 | break; | 
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| 389 | } | 
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| 390 |  | 
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| 391 | /* Don't return an empty string.  GNU libc and GNU libiconv interpret | 
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| 392 | the empty string as denoting "the locale's character encoding", | 
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| 393 | thus GNU libiconv would call this function a second time.  */ | 
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| 394 | if (codeset[0] == '\0') | 
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| 395 | codeset = "ASCII"; | 
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| 396 |  | 
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| 397 | return codeset; | 
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| 398 | } | 
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