glibc/libidn/toutf8.c

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/* toutf8.c Convert strings from system locale into UTF-8.
* Copyright (C) 2002, 2003, 2004 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/param.h>
#include "stringprep.h"
#ifdef _LIBC
# define HAVE_ICONV 1
# define LOCALE_WORKS 1
# define ICONV_CONST
#endif
#ifdef HAVE_ICONV
# include <iconv.h>
# if LOCALE_WORKS
# include <langinfo.h>
# include <locale.h>
# endif
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# ifdef _LIBC
# define stringprep_locale_charset() nl_langinfo (CODESET)
# else
/**
* stringprep_locale_charset:
*
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* 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.
*
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* 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.
*
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* 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)
{
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const char *charset = getenv ("CHARSET"); /* flawfinder: ignore */
if (charset && *charset)
return charset;
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# ifdef LOCALE_WORKS
charset = nl_langinfo (CODESET);
if (charset && *charset)
return charset;
# endif
return "ASCII";
}
# endif
/**
* stringprep_convert:
* @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)
{
iconv_t cd;
char *dest;
char *outp;
ICONV_CONST char *p;
size_t inbytes_remaining;
size_t outbytes_remaining;
size_t err;
size_t outbuf_size;
int have_error = 0;
if (strcmp (to_codeset, from_codeset) == 0)
{
#if defined HAVE_STRDUP || defined _LIBC
return strdup (str);
#else
char *p;
p = malloc (strlen (str) + 1);
if (!p)
return NULL;
return strcpy (p, str);
#endif
}
cd = iconv_open (to_codeset, from_codeset);
if (cd == (iconv_t) - 1)
return NULL;
p = (ICONV_CONST char *) str;
inbytes_remaining = strlen (p);
/* Guess the maximum length the output string can have. */
outbuf_size = (inbytes_remaining + 1) * MAX (7, MB_CUR_MAX);
outp = dest = malloc (outbuf_size);
if (dest == NULL)
goto out;
outbytes_remaining = outbuf_size - 1; /* -1 for NUL */
again:
err = iconv (cd, (ICONV_CONST char **) &p, &inbytes_remaining,
&outp, &outbytes_remaining);
if (err == (size_t) - 1)
{
switch (errno)
{
case EINVAL:
/* Incomplete text, do not report an error */
break;
case E2BIG:
{
size_t used = outp - dest;
char *newdest;
outbuf_size *= 2;
newdest = realloc (dest, outbuf_size);
if (newdest == NULL)
{
have_error = 1;
goto out;
}
dest = newdest;
outp = dest + used;
outbytes_remaining = outbuf_size - used - 1; /* -1 for NUL */
goto again;
}
break;
case EILSEQ:
have_error = 1;
break;
default:
have_error = 1;
break;
}
}
*outp = '\0';
if (*p != '\0')
have_error = 1;
out:
iconv_close (cd);
if (have_error)
{
free (dest);
dest = NULL;
}
return dest;
}
#else /* HAVE_ICONV */
const char *
stringprep_locale_charset ()
{
return "ASCII";
}
char *
stringprep_convert (const char *str,
const char *to_codeset, const char *from_codeset)
{
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;
strcpy (p, str);
return p;
}
#endif /* HAVE_ICONV */
/**
* stringprep_locale_to_utf8:
* @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:
* @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");
}