charset.c

video linux conference

/*****************************************************************************
 * charset.c: Determine a canonical name for the current locale's character
 *            encoding.
 *****************************************************************************
 * Copyright (C) 2003-2004 VideoLAN
 * $Id: charset.c 10101 2005-03-02 16:47:31Z robux4 $
 *
 * Author: Derk-Jan Hartman <thedj at users.sf.net>
 *
 * vlc_current_charset() an adaption of mp_locale_charset():
 *
 *  Copyright (C) 2001-2003 The Mape Project
 *  Written by Karel Zak  <[e-mail]>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include <stdlib.h>
#include <stdio.h>
#include <vlc/vlc.h>

#if !defined WIN32
# if HAVE_LANGINFO_CODESET
#  include <langinfo.h>
# else
#  if HAVE_SETLOCALE
#   include <locale.h>
#  endif
# endif
#elif defined WIN32
# include <windows.h>
#endif

#include "charset.h"

typedef struct VLCCharsetAlias
{
    char *psz_alias, *psz_name;
} VLCCharsetAlias;

/*
 * The libcharset load all from external text file, but it's strange and
 * slow solution, we rather use array(s) compiled into source. In the
 * "good" libc this is not needful -- for example in linux.
 *
 * Please, put to this funtion exotic aliases only. The libc 'iconv' knows
 * a lot of basic aliases (check it first by iconv -l).
 *
 */

static const char* vlc_encoding_from_language( const char *l )
{
    /* check for language (and perhaps country) codes */
    if (strstr(l, "zh_TW")) return "Big5";
    if (strstr(l, "zh_HK")) return "Big5HKSCS";   /* no MIME charset */
    if (strstr(l, "zh")) return "GB2312";
    if (strstr(l, "th")) return "TIS-620";
    if (strstr(l, "ja")) return "EUC-JP";
    if (strstr(l, "ko")) return "EUC-KR";
    if (strstr(l, "ru")) return "KOI8-R";
    if (strstr(l, "uk")) return "KOI8-U";
    if (strstr(l, "pl") || strstr(l, "hr") ||
        strstr(l, "hu") || strstr(l, "cs") ||
        strstr(l, "sk") || strstr(l, "sl")) return "ISO-8859-2";
    if (strstr(l, "eo") || strstr(l, "mt")) return "ISO-8859-3";
    if (strstr(l, "lt") || strstr(l, "la")) return "ISO-8859-4";
    if (strstr(l, "bg") || strstr(l, "be") ||
        strstr(l, "mk") || strstr(l, "uk")) return "ISO-8859-5";
    if (strstr(l, "ar")) return "ISO-8859-6";
    if (strstr(l, "el")) return "ISO-8859-7";
    if (strstr(l, "he") || strstr(l, "iw")) return "ISO-8859-8";
    if (strstr(l, "tr")) return "ISO-8859-9";
    if (strstr(l, "th")) return "ISO-8859-11";
    if (strstr(l, "lv")) return "ISO-8859-13";
    if (strstr(l, "cy")) return "ISO-8859-14";
    if (strstr(l, "et")) return "ISO-8859-15"; /* all latin1 could be iso15 as well */
    if (strstr(l, "ro")) return "ISO-8859-2";   /* or ISO-8859-16 */
    if (strstr(l, "am") || strstr(l, "vi")) return "UTF-8";
    /* We don't know. This ain't working go to default. */
    return "ISO-8859-1";
}


static const char* vlc_charset_aliases( const char *psz_name )
{
    VLCCharsetAlias     *a;

#if defined WIN32
    VLCCharsetAlias aliases[] =
    {
        { "CP936",      "GBK" },
        { "CP1361",     "JOHAB" },
        { "CP20127",    "ASCII" },
        { "CP20866",    "KOI8-R" },
        { "CP21866",    "KOI8-RU" },
        { "CP28591",    "ISO-8859-1" },
        { "CP28592",    "ISO-8859-2" },
        { "CP28593",    "ISO-8859-3" },
        { "CP28594",    "ISO-8859-4" },
        { "CP28595",    "ISO-8859-5" },
        { "CP28596",    "ISO-8859-6" },
        { "CP28597",    "ISO-8859-7" },
        { "CP28598",    "ISO-8859-8" },
        { "CP28599",    "ISO-8859-9" },
        { "CP28605",    "ISO-8859-15" },
        { NULL,         NULL }
    };
#elif SYS_AIX
    VLCCharsetAlias aliases[] =
    {
        { "IBM-850",    "CP850" },
        { "IBM-856",    "CP856" },
        { "IBM-921",    "ISO-8859-13" },
        { "IBM-922",    "CP922" },
        { "IBM-932",    "CP932" },
        { "IBM-943",    "CP943" },
        { "IBM-1046",   "CP1046" },
        { "IBM-1124",   "CP1124" },
        { "IBM-1129",   "CP1129" },
        { "IBM-1252",   "CP1252" },
        { "IBM-EUCCN",  "GB2312" },
        { "IBM-EUCJP",  "EUC-JP" },
        { "IBM-EUCKR",  "EUC-KR" },
        { "IBM-EUCTW",  "EUC-TW" },
        { NULL, NULL }
    };
#elif SYS_HPUX
    VLCCharsetAlias aliases[] =
    {
        { "ROMAN8",     "HP-ROMAN8" },
        { "ARABIC8",    "HP-ARABIC8" },
        { "GREEK8",     "HP-GREEK8" },
        { "HEBREW8",    "HP-HEBREW8" },
        { "TURKISH8",   "HP-TURKISH8" },
        { "KANA8",      "HP-KANA8" },
        { "HP15CN",     "GB2312" },
        { NULL, NULL }
    };
#elif SYS_IRIX
    VLCCharsetAlias aliases[] =
    {
        { "EUCCN",      "GB2312" },
        { NULL, NULL }
    };
#elif SYS_OSF
    VLCCharsetAlias aliases[] =
    {
        { "KSC5601",    "CP949" },
        { "SDECKANJI",  "EUC-JP" },
        { "TACTIS",     "TIS-620" },
        { NULL, NULL }
    };
#elif SYS_SOLARIS
    VLCCharsetAlias aliases[] =
    {
        { "646",        "ASCII" },
        { "CNS11643",   "EUC-TW" },
        { "5601",       "EUC-KR" },
        { "JOHAP92",    "JOHAB" },
        { "PCK",        "SHIFT_JIS" },
        { "2533",       "TIS-620" },
        { NULL, NULL }
    };
#elif SYS_BSD
    VLCCharsetAlias aliases[] =
    {
        { "646", " ASCII" },
        { "EUCCN", "GB2312" },
        { NULL, NULL }
    };
#else
    VLCCharsetAlias aliases[] = {{NULL, NULL}};
#endif

    if( aliases )
    {
        for (a = aliases; a->psz_alias; a++)
            if (strcasecmp (a->psz_alias, psz_name) == 0)
                return a->psz_name;
    }

    /* we return original name beacuse iconv() probably will know
     * something better about name if we don't know it :-) */
    return psz_name;
}

/* Returns charset from "language_COUNTRY.charset@modifier" string */
static char *vlc_encoding_from_locale( char *psz_locale )
{
    char *psz_dot = strchr( psz_locale, '.' );

    if( psz_dot != NULL )
    {
        const char *psz_modifier;
        static char buf[2 + 10 + 1];

        psz_dot++;

        /* Look for the possible @... trailer and remove it, if any.  */
        psz_modifier = strchr( psz_dot, '@' );

        if( psz_modifier == NULL )
            return psz_dot;
        if( 0 < ( psz_modifier - psz_dot ) < sizeof( buf ))
        {
            memcpy( buf, psz_dot, psz_modifier - psz_dot );
            buf[ psz_modifier - psz_dot ] = '\0';
            return buf;
        }
    }
    /* try language mapping */
    return (char *)vlc_encoding_from_language( psz_locale );
}

vlc_bool_t vlc_current_charset( char **psz_charset )
{
    const char *psz_codeset;

#if !(defined WIN32 || defined OS2)

# if HAVE_LANGINFO_CODESET
    /* Most systems support nl_langinfo( CODESET ) nowadays.  */
    psz_codeset = nl_langinfo( CODESET );
# else
    /* On old systems which lack it, use setlocale or getenv.  */
    const char *psz_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. Darwin's setlocale is broken. */
#  if HAVE_SETLOCALE && !SYS_DARWIN
    psz_locale = setlocale( LC_ALL, NULL );
#  endif
    if( psz_locale == NULL || psz_locale[0] == '\0' )
    {
        psz_locale = getenv( "LC_ALL" );
        if( psz_locale == NULL || psz_locale[0] == '\0' )
        {
            psz_locale = getenv( "LC_CTYPE" );
            if( psz_locale == NULL || psz_locale[0] == '\0')
                psz_locale = getenv( "LANG" );
        }
    }

    /* On some old systems, one used to set locale = "iso8859_1". On others,
     * you set it to "language_COUNTRY.charset". Darwin only has LANG :( */
    psz_codeset = vlc_encoding_from_locale( (char *)psz_locale );
# endif /* HAVE_LANGINFO_CODESET */

#elif defined WIN32

    static char buf[2 + 10 + 1];

    /* Woe32 has a function returning the locale's codepage as a number.  */
    sprintf( buf, "CP%u", GetACP() );
    psz_codeset = buf;

#elif defined OS2

    const char *psz_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. */
    psz_locale = getenv( "LC_ALL" );
    if( psz_locale == NULL || psz_locale[0] == '\0' )
    {
        psz+locale = getenv( "LC_CTYPE" );
        if( psz_locale == NULL || locale[0] == '\0' )
            locale = getenv( "LANG" );
    }
    if( psz_locale != NULL && psz_locale[0] != '\0' )
        psz_codeset = vlc_encoding_from_locale( psz_locale );
    else
    {
        /* OS/2 has a function returning the locale's codepage as a number. */
        if( DosQueryCp( sizeof( cp ), cp, &cplen ) )
            psz_codeset = "";
        else
        {
            sprintf( buf, "CP%u", cp[0] );
            psz_codeset = buf;
        }
    }
#endif
    if( psz_codeset == NULL )
        /* The canonical name cannot be determined. */
        psz_codeset = "";
    else
        psz_codeset = vlc_charset_aliases( psz_codeset );

    /* 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( psz_codeset[0] == '\0' )
    {
        /* Last possibility is 'CHARSET' enviroment variable */
        if( !( psz_codeset = getenv( "CHARSET" ) ) )
            psz_codeset = "ISO-8859-1";
    }

    if( psz_charset )
        *psz_charset = strdup((char *)psz_codeset);

    if( !strcasecmp(psz_codeset, "UTF8") || !strcasecmp(psz_codeset, "UTF-8") )
        return VLC_TRUE;

    return VLC_FALSE;
}