utf_tools.php

通过基于Windows的图形化界面

			{
				trigger_error('CJK reencoder file is missing', E_USER_ERROR);
			}
			include($phpbb_root_path . 'includes/utf/data/recode_cjk.' . $phpEx);
		}
		return euc_kr($string);
	}

	// BIG-5
	if (preg_match('/big[_ -]?5/', $encoding))
	{
		if (!function_exists('big5'))
		{
			if (!file_exists($phpbb_root_path . 'includes/utf/data/recode_cjk.' . $phpEx))
			{
				trigger_error('CJK reencoder file is missing', E_USER_ERROR);
			}
			include($phpbb_root_path . 'includes/utf/data/recode_cjk.' . $phpEx);
		}
		return big5($string);
	}

	// GB2312
	if (preg_match('/gb[_ -]?2312/', $encoding))
	{
		if (!function_exists('gb2312'))
		{
			if (!file_exists($phpbb_root_path . 'includes/utf/data/recode_cjk.' . $phpEx))
			{
				trigger_error('CJK reencoder file is missing', E_USER_ERROR);
			}
			include($phpbb_root_path . 'includes/utf/data/recode_cjk.' . $phpEx);
		}
		return gb2312($string);
	}

	// Trigger an error?! Fow now just give bad data :-(
	//trigger_error('Unknown encoding: ' . $encoding, E_USER_ERROR);
	return $string;
}

/**
* Replace all UTF-8 chars that are not in ASCII with their NCR
*
* @param	string	$text		UTF-8 string in NFC
* @return	string				ASCII string using NCRs for non-ASCII chars
*/
function utf8_encode_ncr($text)
{
	return preg_replace_callback('#[\\xC2-\\xF4][\\x80-\\xBF]{1,3}#', 'utf8_encode_ncr_callback', $text);
}

/**
* Callback used in encode_ncr()
*
* Takes a UTF-8 char and replaces it with its NCR. Attention, $m is an array
*
* @param	array	$m			0-based numerically indexed array passed by preg_replace_callback()
* @return	string				A HTML NCR if the character is valid, or the original string otherwise
*/
function utf8_encode_ncr_callback($m)
{
	return '&#' . utf8_ord($m[0]) . ';';
}

/**
* Enter description here...
*
* @param string $chr UTF-8 char
* @return integer UNICODE code point
*/
function utf8_ord($chr)
{
	switch (strlen($chr))
	{
		case 1:
			return ord($chr);
		break;

		case 2:
			return ((ord($chr[0]) & 0x1F) << 6) | (ord($chr[1]) & 0x3F);
		break;

		case 3:
			return ((ord($chr[0]) & 0x0F) << 12) | ((ord($chr[1]) & 0x3F) << 6) | (ord($chr[2]) & 0x3F);
		break;

		case 4:
			return ((ord($chr[0]) & 0x07) << 18) | ((ord($chr[1]) & 0x3F) << 12) | ((ord($chr[2]) & 0x3F) << 6) | (ord($chr[3]) & 0x3F);
		break;

		default:
			return $chr;
	}
}

/**
* Converts an NCR to a UTF-8 char
*
* @param	int		$cp	UNICODE code point
* @return	string		UTF-8 char
*/
function utf8_chr($cp)
{
	if ($cp > 0xFFFF)
	{
		return chr(0xF0 | ($cp >> 18)) . chr(0x80 | (($cp >> 12) & 0x3F)) . chr(0x80 | (($cp >> 6) & 0x3F)) . chr(0x80 | ($cp & 0x3F));
	}
	else if ($cp > 0x7FF)
	{
		return chr(0xE0 | ($cp >> 12)) . chr(0x80 | (($cp >> 6) & 0x3F)) . chr(0x80 | ($cp & 0x3F));
	}
	else if ($cp > 0x7F)
	{
		return chr(0xC0 | ($cp >> 6)) . chr(0x80 | ($cp & 0x3F));
	}
	else
	{
		return chr($cp);
	}
}

/**
* Convert Numeric Character References to UTF-8 chars
*
* Notes:
*	- we do not convert NCRs recursively, if you pass &#38;#38; it will return &#38;
*	- we DO NOT check for the existence of the Unicode characters, therefore an entity may be converted to an inexistent codepoint
*
* @param	string	$text		String to convert, encoded in UTF-8 (no normal form required)
* @return	string				UTF-8 string where NCRs have been replaced with the actual chars
*/
function utf8_decode_ncr($text)
{
	return preg_replace_callback('/&#([0-9]{1,6}|x[0-9A-F]{1,5});/i', 'utf8_decode_ncr_callback', $text);
}

/**
* Callback used in decode_ncr()
*
* Takes a NCR (in decimal or hexadecimal) and returns a UTF-8 char. Attention, $m is an array.
* It will ignore most of invalid NCRs, but not all!
*
* @param	array	$m			0-based numerically indexed array passed by preg_replace_callback()
* @return	string				UTF-8 char
*/
function utf8_decode_ncr_callback($m)
{
	$cp = (strncasecmp($m[1], 'x', 1)) ? $m[1] : hexdec(substr($m[1], 1));

	return utf8_chr($cp);
}

/**
* Takes an array of ints representing the Unicode characters and returns
* a UTF-8 string.
*
* @param	string	$text	text to be case folded
* @param	string	$option	determines how we will fold the cases
* @return	string			case folded text
*/
function utf8_case_fold($text, $option = 'full')
{
	static $uniarray = array();
	global $phpbb_root_path, $phpEx;

	// common is always set
	if (!isset($uniarray['c']))
	{
		$uniarray['c'] = include($phpbb_root_path . 'includes/utf/data/case_fold_c.' . $phpEx);
	}

	// only set full if we need to
	if ($option === 'full' && !isset($uniarray['f']))
	{
		$uniarray['f'] = include($phpbb_root_path . 'includes/utf/data/case_fold_f.' . $phpEx);
	}

	// only set simple if we need to
	if ($option !== 'full' && !isset($uniarray['s']))
	{
		$uniarray['s'] = include($phpbb_root_path . 'includes/utf/data/case_fold_s.' . $phpEx);
	}

	$text = strtr($text, $uniarray['c']);
	if ($option === 'full')
	{
		$text = strtr($text, $uniarray['f']);
	}
	else
	{
		$text = strtr($text, $uniarray['s']);
	}
	return $text;
}

/**
* A wrapper function for the normalizer which takes care of including the class if required and modifies the passed strings
* to be in NFC (Normalization Form Composition).
*
* @param	mixed	$strings	a string or an array of strings to normalize
* @return	mixed				the normalized content, preserving array keys if array given.
*/
function utf8_normalize_nfc($strings)
{
	if (empty($strings))
	{
		return $strings;
	}

	if (!class_exists('utf_normalizer'))
	{
		global $phpbb_root_path, $phpEx;
		include($phpbb_root_path . 'includes/utf/utf_normalizer.' . $phpEx);
	}

	if (!is_array($strings))
	{
		utf_normalizer::nfc($strings);
	}
	else if (is_array($strings))
	{
		foreach ($strings as $key => $string)
		{
			utf_normalizer::nfc($strings[$key]);
		}
	}

	return $strings;
}

/**
* This function is used to generate a "clean" version of a string.
* Clean means that it is a case insensitive form (case folding) and that it is normalized (NFC).
* Additionally a homographs of one character are transformed into one specific character (preferably ASCII
* if it is an ASCII character).
*
* Please be aware that if you change something within this function or within
* functions used here you need to rebuild/update the username_clean column in the users table. And all other
* columns that store a clean string otherwise you will break this functionality.
*
* @param	string	$text	An unclean string, mabye user input (has to be valid UTF-8!)
* @return	string			Cleaned up version of the input string
*/
function utf8_clean_string($text)
{
	$text = utf8_case_fold($text);
	
	if (!class_exists('utf_normalizer'))
	{
		global $phpbb_root_path, $phpEx;
		include($phpbb_root_path . 'includes/utf/utf_normalizer.' . $phpEx);
	}

	utf_normalizer::nfc($text);

	static $homographs = array(
		"\xC2\xA1"			=>	"\x69",				// EXCLAMATION MARK, INVERTED => LATIN SMALL LETTER I
		"\xC2\xAD"			=>	'',					// HYPHEN, SOFT => empty string
		"\xC4\x90"			=>	"\xC3\x90",			// LATIN CAPITAL LETTER D WITH STROKE => LATIN CAPITAL LETTER ETH
		"\xC7\x83"			=>	"\x21",				// LATIN LETTER RETROFLEX CLICK => EXCLAMATION MARK
		"\xC9\x85"			=>	"\xCE\x9B",			// LATIN CAPITAL LETTER TURNED V => GREEK CAPITAL LETTER LAMDA
		"\xC9\x99"			=>	"\xC7\x9D",			// LATIN SMALL LETTER SCHWA => LATIN SMALL LETTER TURNED E
		"\xCA\x99"			=>	"\xD0\xB2",			// LATIN LETTER SMALL CAPITAL B => CYRILLIC SMALL LETTER VE
		"\xCA\x9C"			=>	"\xD0\xBD",			// LATIN LETTER SMALL CAPITAL H => CYRILLIC SMALL LETTER EN
		"\xCE\x91"			=>	"\x41",				// GREEK CAPITAL LETTER ALPHA => LATIN CAPITAL LETTER A
		"\xCE\x92"			=>	"\x42",				// GREEK CAPITAL LETTER BETA => LATIN CAPITAL LETTER B
		"\xCE\x95"			=>	"\x45",				// GREEK CAPITAL LETTER EPSILON => LATIN CAPITAL LETTER E
		"\xCE\x96"			=>	"\x5A",				// GREEK CAPITAL LETTER ZETA => LATIN CAPITAL LETTER Z
		"\xCE\x97"			=>	"\x48",				// GREEK CAPITAL LETTER ETA => LATIN CAPITAL LETTER H
		"\xCE\x99"			=>	"\x49",				// GREEK CAPITAL LETTER IOTA => LATIN CAPITAL LETTER I
		"\xCE\x9A"			=>	"\x4B",				// GREEK CAPITAL LETTER KAPPA => LATIN CAPITAL LETTER K
		"\xCE\x9C"			=>	"\x4D",				// GREEK CAPITAL LETTER MU => LATIN CAPITAL LETTER M
		"\xCE\x9D"			=>	"\x4E",				// GREEK CAPITAL LETTER NU => LATIN CAPITAL LETTER N
		"\xCE\x9F"			=>	"\x4F",				// GREEK CAPITAL LETTER OMICRON => LATIN CAPITAL LETTER O
		"\xCE\xA1"			=>	"\x50",				// GREEK CAPITAL LETTER RHO => LATIN CAPITAL LETTER P
		"\xCE\xA3"			=>	"\xC6\xA9",			// GREEK CAPITAL LETTER SIGMA => LATIN CAPITAL LETTER ESH
		"\xCE\xA4"			=>	"\x54",				// GREEK CAPITAL LETTER TAU => LATIN CAPITAL LETTER T
		"\xCE\xA5"			=>	"\x59",				// GREEK CAPITAL LETTER UPSILON => LATIN CAPITAL LETTER Y
		"\xCE\xA7"			=>	"\x58",				// GREEK CAPITAL LETTER CHI => LATIN CAPITAL LETTER X
		"\xCE\xB1"			=>	"\x61",				// GREEK SMALL LETTER ALPHA => LATIN SMALL LETTER A
		"\xCE\xB5"			=>	"\xC9\x9B",			// GREEK SMALL LETTER EPSILON => LATIN SMALL LETTER OPEN E
		"\xCE\xB9"			=>	"\xC9\xA9",			// GREEK SMALL LETTER IOTA => LATIN SMALL LETTER IOTA
		"\xCE\xBF"			=>	"\x6F",				// GREEK SMALL LETTER OMICRON => LATIN SMALL LETTER O
		"\xCF\xB3"			=>	"\x6A",				// GREEK LETTER YOT => LATIN SMALL LETTER J
		"\xD0\x85"			=>	"\x53",				// CYRILLIC CAPITAL LETTER DZE => LATIN CAPITAL LETTER S
		"\xD0\x88"			=>	"\x4A",				// CYRILLIC CAPITAL LETTER JE => LATIN CAPITAL LETTER J
		"\xD0\x91"			=>	"\xC6\x82",			// CYRILLIC CAPITAL LETTER BE => LATIN CAPITAL LETTER B WITH TOPBAR
		"\xD0\x93"			=>	"\xCE\x93",			// CYRILLIC CAPITAL LETTER GHE => GREEK CAPITAL LETTER GAMMA
		"\xD0\x9F"			=>	"\xCE\xA0",			// CYRILLIC CAPITAL LETTER PE => GREEK CAPITAL LETTER PI
		"\xD0\xA1"			=>	"\x43",				// CYRILLIC CAPITAL LETTER ES => LATIN CAPITAL LETTER C
		"\xD0\xB0"			=>	"\x61",				// CYRILLIC SMALL LETTER A => LATIN SMALL LETTER A
		"\xD0\xB5"			=>	"\x65",				// CYRILLIC SMALL LETTER IE => LATIN SMALL LETTER E
		"\xD0\xBA"			=>	"\xC4\xB8",			// CYRILLIC SMALL LETTER KA => LATIN SMALL LETTER KRA
		"\xD0\xBE"			=>	"\x6F",				// CYRILLIC SMALL LETTER O => LATIN SMALL LETTER O
		"\xD1\x80"			=>	"\x70",				// CYRILLIC SMALL LETTER ER => LATIN SMALL LETTER P
		"\xD1\x81"			=>	"\x63",				// CYRILLIC SMALL LETTER ES => LATIN SMALL LETTER C
		"\xD1\x83"			=>	"\x79",				// CYRILLIC SMALL LETTER U => LATIN SMALL LETTER Y
		"\xD1\x85"			=>	"\x78",				// CYRILLIC SMALL LETTER HA => LATIN SMALL LETTER X
		"\xD1\x95"			=>	"\x73",				// CYRILLIC SMALL LETTER DZE => LATIN SMALL LETTER S
		"\xD1\x96"			=>	"\x69",				// CYRILLIC SMALL LETTER BYELORUSSIAN-UKRAINIAN I => LATIN SMALL LETTER I
		"\xD1\x98"			=>	"\x6A",				// CYRILLIC SMALL LETTER JE => LATIN SMALL LETTER J
		"\xD2\xBB"			=>	"\x68",				// CYRILLIC SMALL LETTER SHHA => LATIN SMALL LETTER H
		"\xD3\x8F"			=>	"\xC9\xAA",			// CYRILLIC SMALL LETTER PALOCHKA => LATIN LETTER SMALL CAPITAL I
		"\xD3\x94"			=>	"\xC3\x86",			// CYRILLIC CAPITAL LIGATURE A IE => LATIN CAPITAL LETTER AE
		"\xD3\x95"			=>	"\xC3\xA6",			// CYRILLIC SMALL LIGATURE A IE => LATIN SMALL LETTER AE
		"\xD3\x98"			=>	"\xC6\x8E",			// CYRILLIC CAPITAL LETTER SCHWA => LATIN CAPITAL LETTER REVERSED E
		"\xD3\x99"			=>	"\xC7\x9D",			// CYRILLIC SMALL LETTER SCHWA => LATIN SMALL LETTER TURNED E
		"\xD3\xA1"			=>	"\xCA\x92",			// CYRILLIC SMALL LETTER ABKHASIAN DZE => LATIN SMALL LETTER EZH
		"\xD3\xA8"			=>	"\xC6\x9F",			// CYRILLIC CAPITAL LETTER BARRED O => LATIN CAPITAL LETTER O WITH MIDDLE TILDE
		"\xD3\xA9"			=>	"\xC9\xB5",			// CYRILLIC SMALL LETTER BARRED O => LATIN SMALL LETTER BARRED O
		"\xD4\x81"			=>	"\x64",				// CYRILLIC SMALL LETTER KOMI DE => LATIN SMALL LETTER D
		"\xE1\x81\x80"		=>	"\xE1\x80\x9D",		// MYANMAR DIGIT ZERO => MYANMAR LETTER WA
		"\xE1\x9E\xA3"		=>	"\xE1\x9E\xA2",		// KHMER INDEPENDENT VOWEL QAQ => KHMER LETTER QA
		"\xE1\xA1\x95"		=>	"\xE1\xA0\xB5",		// MONGOLIAN LETTER TODO YA => MONGOLIAN LETTER JA
		"\xE1\xA7\x90"		=>	"\xE1\xA6\x9E",		// NEW TAI LUE DIGIT ZERO => NEW TAI LUE LETTER LOW VA
		"\xE1\xAD\x92"		=>	"\xE1\xAC\x8D",		// BALINESE DIGIT TWO => BALINESE LETTER LA LENGA
		"\xE1\xAD\x93"		=>	"\xE1\xAC\x91",		// BALINESE DIGIT THREE => BALINESE LETTER OKARA
		"\xE1\xAD\x98"		=>	"\xE1\xAC\xA8",		// BALINESE DIGIT EIGHT => BALINESE LETTER PA KAPAL
		"\xE1\xAD\x9C"		=>	"\xE1\xAD\x90",		// BALINESE WINDU => BALINESE DIGIT ZERO
		"\xE1\xB4\x8D"		=>	"\xD0\xBC",			// LATIN LETTER SMALL CAPITAL M => CYRILLIC SMALL LETTER EM
		"\xE1\xB4\x9B"		=>	"\xD1\x82",			// LATIN LETTER SMALL CAPITAL T => CYRILLIC SMALL LETTER TE
		"\xE1\xB4\xA6"		=>	"\xD0\xB3",			// GREEK LETTER SMALL CAPITAL GAMMA => CYRILLIC SMALL LETTER GHE
		"\xE1\xB4\xA8"		=>	"\xD0\xBF",			// GREEK LETTER SMALL CAPITAL PI => CYRILLIC SMALL LETTER PE
		"\xE1\xB4\xA9"		=>	"\xE1\xB4\x98",		// GREEK LETTER SMALL CAPITAL RHO => LATIN LETTER SMALL CAPITAL P
		"\xE1\xB4\xAB"		=>	"\xD0\xBB",			// CYRILLIC LETTER SMALL CAPITAL EL => CYRILLIC SMALL LETTER EL
		"\xE2\x8D\xB3"		=>	"\xC9\xA9",			// APL FUNCTIONAL SYMBOL IOTA => LATIN SMALL LETTER IOTA
		"\xE2\x8D\xB4"		=>	"\xCF\x81",			// APL FUNCTIONAL SYMBOL RHO => GREEK SMALL LETTER RHO
		"\xE2\x8D\xB5"		=>	"\xCF\x89",			// APL FUNCcTIONAL SYMBOL OMEGA => GREEK SMALL LETTER OMEGA
		"\xE2\x8D\xBA"		=>	"\xCE\xB1",			// APL FUNCTIONAL SYMBOL ALPHA => GREEK SMALL LETTER ALPHA
		"\xE2\xB1\xA7"		=>	"\xD2\xA2",			// LATIN CAPITAL LETTER H WITH DESCENDER => CYRILLIC CAPITAL LETTER EN WITH DESCENDER
		"\xE2\xB1\xA9"		=>	"\xD2\x9A",			// LATIN CAPITAL LETTER K WITH DESCENDER => CYRILLIC CAPITAL LETTER KA WITH DESCENDER
		"\xF0\x90\x8F\x91"	=>	"\xF0\x90\x8E\x82",	// OLD PERSIAN NUMBER ONE => UGARITIC LETTER GAMLA
		"\xF0\x90\x8F\x93"	=>	"\xF0\x90\x8E\x93",	// OLD PERSIAN NUMBER TEN => UGARITIC LETTER AIN
		"\xF0\x90\x92\xA0"	=>	"\xF0\x90\x92\x86",	// OSMANYA DIGIT ZERO => OSMANYA LETTER DEEL
		"\xF0\x92\x80\xB8"	=>	"\xF0\x90\x8E\x9A",	// CUNEIFORM SIGN ASH => UGARITIC LETTER TO

		"\xC2\xA0"			=>	"\x20",				// NO-BREAK SPACE
		"\xE1\x9A\x80"		=>	"\x20",				// OGHAM SPACE MARK
		"\xE2\x80\x80"		=>	"\x20",				// EN QUAD
		"\xE2\x80\x81"		=>	"\x20",				// EM QUAD
		"\xE2\x80\x82"		=>	"\x20",				// EN SPACE
		"\xE2\x80\x83"		=>	"\x20",				// EM SPACE
		"\xE2\x80\x84"		=>	"\x20",				// THREE-PER-EM SPACE
		"\xE2\x80\x85"		=>	"\x20",				// FOUR-PER-EM SPACE
		"\xE2\x80\x86"		=>	"\x20",				// SIX-PER-EM SPACE
		"\xE2\x80\x87"		=>	"\x20",				// FIGURE SPACE
		"\xE2\x80\x88"		=>	"\x20",				// PUNCTUATION SPACE
		"\xE2\x80\x89"		=>	"\x20",				// THIN SPACE
		"\xE2\x80\x8A"		=>	"\x20",				// HAIR SPACE
		"\xE2\x80\xAF"		=>	"\x20",				// NARROW NO-BREAK SPACE
		"\xE2\x81\x9F"		=>	"\x20",				// MEDIUM MATHEMATICAL SPACE
		"\xE3\x80\x80"		=>	"\x20",				// IDEOGRAPHIC SPACE

		"\xDB\x9D"			=>	'',					// ARABIC END OF AYAH
		"\xDC\x8F"			=>	'',					// SYRIAC ABBREVIATION MARK
		"\xE1\xA0\x86"		=>	'',					// MONGOLIAN TODO SOFT HYPHEN
		"\xE1\xA0\x8E"		=>	'',					// MONGOLIAN VOWEL SEPARATOR
		"\xE2\x80\x8B"		=>	'',					// ZERO WIDTH SPACE
		"\xE2\x80\x8C"		=>	'',					// ZERO WIDTH NON-JOINER
		"\xE2\x80\x8D"		=>	'',					// ZERO WIDTH JOINER
		"\xE2\x80\xA8"		=>	'',					// LINE SEPARATOR
		"\xE2\x80\xA9"		=>	'',					// PARAGRAPH SEPARATOR
		"\xE2\x81\xA0"		=>	'',					// WORD JOINER
		"\xE2\x81\xA1"		=>	'',					// FUNCTION APPLICATION
		"\xE2\x81\xA2"		=>	'',					// INVISIBLE TIMES
		"\xE2\x81\xA3"		=>	'',					// INVISIBLE SEPARATOR
		"\xE2\x81\xAA"		=>	'',					// [CONTROL CHARACTERS]
		"\xE2\x81\xAB"		=>	'',					// [CONTROL CHARACTERS]
		"\xE2\x81\xAC"		=>	'',					// [CONTROL CHARACTERS]
		"\xE2\x81\xAD"		=>	'',					// [CONTROL CHARACTERS]
		"\xE2\x81\xAE"		=>	'',					// [CONTROL CHARACTERS]
		"\xE2\x81\xAF"		=>	'',					// [CONTROL CHARACTERS]
		"\xEF\xBB\xBF"		=>	'',					// ZERO WIDTH NO-BREAK SPACE
		"\xEF\xBF\xB9"		=>	'',					// [CONTROL CHARACTERS]
		"\xEF\xBF\xBA"		=>	'',					// [CONTROL CHARACTERS]
		"\xEF\xBF\xBB"		=>	'',					// [CONTROL CHARACTERS]
		"\xEF\xBF\xBC"		=>	'',					// [CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB3"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB4"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB5"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB6"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB7"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB8"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xB9"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
		"\xF0\x9D\x85\xBA"	=>	'',					// [MUSICAL CONTROL CHARACTERS]
	);

	$text = strtr($text, $homographs);

	// Other control characters
	$text = preg_replace('#(?:[\x00-\x1F\x7F]+|(?:\xC2[\x80-\x9F])+)#', '', $text);

	return $text;
}

/**
* A wrapper for htmlspecialchars($value, ENT_COMPAT, 'UTF-8')
*/
function utf8_htmlspecialchars(&$value)
{
	return htmlspecialchars($value, ENT_COMPAT, 'UTF-8');
}

/**
* Trying to convert returned system message to utf8
*
* PHP assumes such messages are ISO-8859-1 so we'll do that too
* and if it breaks messages we'll blame it on them ;-)
*/
function utf8_convert_message($message)
{
	// First of all check if conversion is neded at all, as there is no point
	// in converting ASCII messages from ISO-8859-1 to UTF-8
	if (!preg_match('/[\x80-\xFF]/', $message))
	{
		return utf8_htmlspecialchars($message);
	}

	// else we need to convert some part of the message
	return utf8_htmlspecialchars(utf8_recode($message, 'ISO-8859-1'));
}

?>