glibc/libidn/toutf8.c

151 lines
4.3 KiB
C

/* toutf8.c --- Convert strings from system locale into UTF-8.
* Copyright (C) 2002, 2003, 2004, 2005 Simon Josefsson
*
* This file is part of GNU Libidn.
*
* GNU Libidn is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* GNU Libidn 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with GNU Libidn; if not, see <http://www.gnu.org/licenses/>.
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
/* Get prototypes. */
#include "stringprep.h"
/* Get fprintf. */
#include <stdio.h>
/* Get getenv. */
#include <stdlib.h>
/* Get strlen. */
#include <string.h>
/* Get iconv_string. */
#include "iconvme.h"
#ifdef _LIBC
# define HAVE_ICONV 1
# define LOCALE_WORKS 1
#endif
#if LOCALE_WORKS
# include <langinfo.h>
# include <locale.h>
#endif
#ifdef _LIBC
# define stringprep_locale_charset() nl_langinfo (CODESET)
#else
/**
* stringprep_locale_charset - return charset used in current locale
*
* Find out current locale charset. The function respect the CHARSET
* environment variable, but typically uses nl_langinfo(CODESET) when
* it is supported. It fall back on "ASCII" if CHARSET isn't set and
* nl_langinfo isn't supported or return anything.
*
* Note that this function return the application's locale's preferred
* charset (or thread's locale's preffered charset, if your system
* support thread-specific locales). It does not return what the
* system may be using. Thus, if you receive data from external
* sources you cannot in general use this function to guess what
* charset it is encoded in. Use stringprep_convert from the external
* representation into the charset returned by this function, to have
* data in the locale encoding.
*
* Return value: Return the character set used by the current locale.
* It will never return NULL, but use "ASCII" as a fallback.
**/
const char *
stringprep_locale_charset (void)
{
const char *charset = getenv ("CHARSET"); /* flawfinder: ignore */
if (charset && *charset)
return charset;
# ifdef LOCALE_WORKS
charset = nl_langinfo (CODESET);
if (charset && *charset)
return charset;
# endif
return "ASCII";
}
#endif
/**
* stringprep_convert - encode string using new character set
* @str: input zero-terminated string.
* @to_codeset: name of destination character set.
* @from_codeset: name of origin character set, as used by @str.
*
* Convert the string from one character set to another using the
* system's iconv() function.
*
* Return value: Returns newly allocated zero-terminated string which
* is @str transcoded into to_codeset.
**/
char *
stringprep_convert (const char *str,
const char *to_codeset, const char *from_codeset)
{
#if HAVE_ICONV
return iconv_string (str, from_codeset, to_codeset);
#else
char *p;
fprintf (stderr, "libidn: warning: libiconv not installed, cannot "
"convert data to UTF-8\n");
p = malloc (strlen (str) + 1);
if (!p)
return NULL;
return strcpy (p, str);
#endif
}
/**
* stringprep_locale_to_utf8 - convert locale encoded string to UTF-8
* @str: input zero terminated string.
*
* Convert string encoded in the locale's character set into UTF-8 by
* using stringprep_convert().
*
* Return value: Returns newly allocated zero-terminated string which
* is @str transcoded into UTF-8.
**/
char *
stringprep_locale_to_utf8 (const char *str)
{
return stringprep_convert (str, "UTF-8", stringprep_locale_charset ());
}
/**
* stringprep_utf8_to_locale - encode UTF-8 string to locale encoding
* @str: input zero terminated string.
*
* Convert string encoded in UTF-8 into the locale's character set by
* using stringprep_convert().
*
* Return value: Returns newly allocated zero-terminated string which
* is @str transcoded into the locale's character set.
**/
char *
stringprep_utf8_to_locale (const char *str)
{
return stringprep_convert (str, stringprep_locale_charset (), "UTF-8");
}