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authorthomascube <thomas@roundcube.net>2012-01-16 15:14:41 +0000
committerthomascube <thomas@roundcube.net>2012-01-16 15:14:41 +0000
commitc321a955a7b0f6d6b13ffaebf040a6c7091037ae (patch)
tree60c257d29a726d9bdda7fb75a198342aaef315fa /program/include/rcube_charset.php
parent8764b6ecf0c8d1b0646915a8139cdf6bbac2ca14 (diff)
Merged devel-framework branch (r5746:5779) back into trunk
Diffstat (limited to 'program/include/rcube_charset.php')
-rw-r--r--program/include/rcube_charset.php745
1 files changed, 745 insertions, 0 deletions
diff --git a/program/include/rcube_charset.php b/program/include/rcube_charset.php
new file mode 100644
index 000000000..29de426d8
--- /dev/null
+++ b/program/include/rcube_charset.php
@@ -0,0 +1,745 @@
+<?php
+
+/*
+ +-----------------------------------------------------------------------+
+ | program/include/rcube_charset.php |
+ | |
+ | This file is part of the Roundcube Webmail client |
+ | Copyright (C) 2005-2012, The Roundcube Dev Team |
+ | Copyright (C) 2011-2012, Kolab Systems AG |
+ | Copyright (C) 2000 Edmund Grimley Evans <edmundo@rano.org> |
+ | Licensed under the GNU GPL |
+ | |
+ | PURPOSE: |
+ | Provide charset conversion functionality |
+ | |
+ +-----------------------------------------------------------------------+
+ | Author: Thomas Bruederli <roundcube@gmail.com> |
+ | Author: Aleksander Machniak <alec@alec.pl> |
+ +-----------------------------------------------------------------------+
+
+ $Id$
+
+*/
+
+/**
+ * Character sets conversion functionality
+ *
+ * @package Core
+ * @author Thomas Bruederli <roundcube@gmail.com>
+ * @author Aleksander Machniak <alec@alec.pl>
+ * @author Edmund Grimley Evans <edmundo@rano.org>
+ */
+class rcube_charset
+{
+ // Aliases: some of them from HTML5 spec.
+ static public $aliases = array(
+ 'USASCII' => 'WINDOWS-1252',
+ 'ANSIX31101983' => 'WINDOWS-1252',
+ 'ANSIX341968' => 'WINDOWS-1252',
+ 'UNKNOWN8BIT' => 'ISO-8859-15',
+ 'UNKNOWN' => 'ISO-8859-15',
+ 'USERDEFINED' => 'ISO-8859-15',
+ 'KSC56011987' => 'EUC-KR',
+ 'GB2312' => 'GBK',
+ 'GB231280' => 'GBK',
+ 'UNICODE' => 'UTF-8',
+ 'UTF7IMAP' => 'UTF7-IMAP',
+ 'TIS620' => 'WINDOWS-874',
+ 'ISO88599' => 'WINDOWS-1254',
+ 'ISO885911' => 'WINDOWS-874',
+ 'MACROMAN' => 'MACINTOSH',
+ '77' => 'MAC',
+ '128' => 'SHIFT-JIS',
+ '129' => 'CP949',
+ '130' => 'CP1361',
+ '134' => 'GBK',
+ '136' => 'BIG5',
+ '161' => 'WINDOWS-1253',
+ '162' => 'WINDOWS-1254',
+ '163' => 'WINDOWS-1258',
+ '177' => 'WINDOWS-1255',
+ '178' => 'WINDOWS-1256',
+ '186' => 'WINDOWS-1257',
+ '204' => 'WINDOWS-1251',
+ '222' => 'WINDOWS-874',
+ '238' => 'WINDOWS-1250',
+ 'MS950' => 'CP950',
+ 'WINDOWS949' => 'UHC',
+ );
+
+
+ /**
+ * Catch an error and throw an exception.
+ *
+ * @param int Level of the error
+ * @param string Error message
+ */
+ public function error_handler($errno, $errstr)
+ {
+ throw new ErrorException($errstr, 0, $errno);
+ }
+
+
+ /**
+ * Parse and validate charset name string (see #1485758).
+ * Sometimes charset string is malformed, there are also charset aliases
+ * but we need strict names for charset conversion (specially utf8 class)
+ *
+ * @param string Input charset name
+ *
+ * @return string The validated charset name
+ */
+ public static function parse($input)
+ {
+ static $charsets = array();
+ $charset = strtoupper($input);
+
+ if (isset($charsets[$input])) {
+ return $charsets[$input];
+ }
+
+ $charset = preg_replace(array(
+ '/^[^0-9A-Z]+/', // e.g. _ISO-8859-JP$SIO
+ '/\$.*$/', // e.g. _ISO-8859-JP$SIO
+ '/UNICODE-1-1-*/', // RFC1641/1642
+ '/^X-/', // X- prefix (e.g. X-ROMAN8 => ROMAN8)
+ ), '', $charset);
+
+ if ($charset == 'BINARY') {
+ return $charsets[$input] = null;
+ }
+
+ // allow A-Z and 0-9 only
+ $str = preg_replace('/[^A-Z0-9]/', '', $charset);
+
+ if (isset(self::$aliases[$str])) {
+ $result = self::$aliases[$str];
+ }
+ // UTF
+ else if (preg_match('/U[A-Z][A-Z](7|8|16|32)(BE|LE)*/', $str, $m)) {
+ $result = 'UTF-' . $m[1] . $m[2];
+ }
+ // ISO-8859
+ else if (preg_match('/ISO8859([0-9]{0,2})/', $str, $m)) {
+ $iso = 'ISO-8859-' . ($m[1] ? $m[1] : 1);
+ // some clients sends windows-1252 text as latin1,
+ // it is safe to use windows-1252 for all latin1
+ $result = $iso == 'ISO-8859-1' ? 'WINDOWS-1252' : $iso;
+ }
+ // handle broken charset names e.g. WINDOWS-1250HTTP-EQUIVCONTENT-TYPE
+ else if (preg_match('/(WIN|WINDOWS)([0-9]+)/', $str, $m)) {
+ $result = 'WINDOWS-' . $m[2];
+ }
+ // LATIN
+ else if (preg_match('/LATIN(.*)/', $str, $m)) {
+ $aliases = array('2' => 2, '3' => 3, '4' => 4, '5' => 9, '6' => 10,
+ '7' => 13, '8' => 14, '9' => 15, '10' => 16,
+ 'ARABIC' => 6, 'CYRILLIC' => 5, 'GREEK' => 7, 'GREEK1' => 7, 'HEBREW' => 8
+ );
+
+ // some clients sends windows-1252 text as latin1,
+ // it is safe to use windows-1252 for all latin1
+ if ($m[1] == 1) {
+ $result = 'WINDOWS-1252';
+ }
+ // if iconv is not supported we need ISO labels, it's also safe for iconv
+ else if (!empty($aliases[$m[1]])) {
+ $result = 'ISO-8859-'.$aliases[$m[1]];
+ }
+ // iconv requires convertion of e.g. LATIN-1 to LATIN1
+ else {
+ $result = $str;
+ }
+ }
+ else {
+ $result = $charset;
+ }
+
+ $charsets[$input] = $result;
+
+ return $result;
+ }
+
+
+ /**
+ * Convert a string from one charset to another.
+ * Uses mbstring and iconv functions if possible
+ *
+ * @param string Input string
+ * @param string Suspected charset of the input string
+ * @param string Target charset to convert to; defaults to RCMAIL_CHARSET
+ *
+ * @return string Converted string
+ */
+ public static function convert($str, $from, $to = null)
+ {
+ static $iconv_options = null;
+ static $mbstring_loaded = null;
+ static $mbstring_list = null;
+ static $conv = null;
+
+ $to = empty($to) ? strtoupper(RCMAIL_CHARSET) : self::parse($to);
+ $from = self::parse($from);
+
+ if ($from == $to || empty($str) || empty($from)) {
+ return $str;
+ }
+
+ // convert charset using iconv module
+ if (function_exists('iconv') && $from != 'UTF7-IMAP' && $to != 'UTF7-IMAP') {
+ if ($iconv_options === null) {
+ // ignore characters not available in output charset
+ $iconv_options = '//IGNORE';
+ if (iconv('', $iconv_options, '') === false) {
+ // iconv implementation does not support options
+ $iconv_options = '';
+ }
+ }
+
+ // throw an exception if iconv reports an illegal character in input
+ // it means that input string has been truncated
+ set_error_handler(array('rcube_charset', 'error_handler'), E_NOTICE);
+ try {
+ $_iconv = iconv($from, $to . $iconv_options, $str);
+ } catch (ErrorException $e) {
+ $_iconv = false;
+ }
+ restore_error_handler();
+
+ if ($_iconv !== false) {
+ return $_iconv;
+ }
+ }
+
+ if ($mbstring_loaded === null) {
+ $mbstring_loaded = extension_loaded('mbstring');
+ }
+
+ // convert charset using mbstring module
+ if ($mbstring_loaded) {
+ $aliases['WINDOWS-1257'] = 'ISO-8859-13';
+
+ if ($mbstring_list === null) {
+ $mbstring_list = mb_list_encodings();
+ $mbstring_list = array_map('strtoupper', $mbstring_list);
+ }
+
+ $mb_from = $aliases[$from] ? $aliases[$from] : $from;
+ $mb_to = $aliases[$to] ? $aliases[$to] : $to;
+
+ // return if encoding found, string matches encoding and convert succeeded
+ if (in_array($mb_from, $mbstring_list) && in_array($mb_to, $mbstring_list)) {
+ if (mb_check_encoding($str, $mb_from) && ($out = mb_convert_encoding($str, $mb_to, $mb_from))) {
+ return $out;
+ }
+ }
+ }
+
+ // convert charset using bundled classes/functions
+ if ($to == 'UTF-8') {
+ if ($from == 'UTF7-IMAP') {
+ if ($_str = self::utf7imap_to_utf8($str)) {
+ return $_str;
+ }
+ }
+ else if ($from == 'UTF-7') {
+ if ($_str = self::utf7_to_utf8($str)) {
+ return $_str;
+ }
+ }
+ else if ($from == 'ISO-8859-1' && function_exists('utf8_encode')) {
+ return utf8_encode($str);
+ }
+ else if (class_exists('utf8')) {
+ if (!$conv) {
+ $conv = new utf8($from);
+ }
+ else {
+ $conv->loadCharset($from);
+ }
+
+ if ($_str = $conv->strToUtf8($str)) {
+ return $_str;
+ }
+ }
+ }
+
+ // encode string for output
+ if ($from == 'UTF-8') {
+ // @TODO: we need a function for UTF-7 (RFC2152) conversion
+ if ($to == 'UTF7-IMAP' || $to == 'UTF-7') {
+ if ($_str = utf8_to_utf7imap($str)) {
+ return $_str;
+ }
+ }
+ else if ($to == 'ISO-8859-1' && function_exists('utf8_decode')) {
+ return utf8_decode($str);
+ }
+ else if (class_exists('utf8')) {
+ if (!$conv) {
+ $conv = new utf8($to);
+ }
+ else {
+ $conv->loadCharset($from);
+ }
+
+ if ($_str = $conv->strToUtf8($str)) {
+ return $_str;
+ }
+ }
+ }
+
+ // return original string
+ return $str;
+ }
+
+
+ /**
+ * Converts string from standard UTF-7 (RFC 2152) to UTF-8.
+ *
+ * @param string Input string (UTF-7)
+ *
+ * @return string Converted string (UTF-8)
+ */
+ public static function utf7_to_utf8($str)
+ {
+ $Index_64 = array(
+ 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
+ 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
+ 0,0,0,0, 0,0,0,0, 0,0,0,1, 0,0,0,0,
+ 1,1,1,1, 1,1,1,1, 1,1,0,0, 0,0,0,0,
+ 0,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1,
+ 1,1,1,1, 1,1,1,1, 1,1,1,0, 0,0,0,0,
+ 0,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1,
+ 1,1,1,1, 1,1,1,1, 1,1,1,0, 0,0,0,0,
+ );
+
+ $u7len = strlen($str);
+ $str = strval($str);
+ $res = '';
+
+ for ($i=0; $u7len > 0; $i++, $u7len--) {
+ $u7 = $str[$i];
+ if ($u7 == '+') {
+ $i++;
+ $u7len--;
+ $ch = '';
+
+ for (; $u7len > 0; $i++, $u7len--) {
+ $u7 = $str[$i];
+
+ if (!$Index_64[ord($u7)]) {
+ break;
+ }
+
+ $ch .= $u7;
+ }
+
+ if ($ch == '') {
+ if ($u7 == '-') {
+ $res .= '+';
+ }
+
+ continue;
+ }
+
+ $res .= self::utf16_to_utf8(base64_decode($ch));
+ }
+ else {
+ $res .= $u7;
+ }
+ }
+
+ return $res;
+ }
+
+
+ /**
+ * Converts string from UTF-16 to UTF-8 (helper for utf-7 to utf-8 conversion)
+ *
+ * @param string Input string
+ *
+ * @return string The converted string
+ */
+ public static function utf16_to_utf8($str)
+ {
+ $len = strlen($str);
+ $dec = '';
+
+ for ($i = 0; $i < $len; $i += 2) {
+ $c = ord($str[$i]) << 8 | ord($str[$i + 1]);
+ if ($c >= 0x0001 && $c <= 0x007F) {
+ $dec .= chr($c);
+ }
+ else if ($c > 0x07FF) {
+ $dec .= chr(0xE0 | (($c >> 12) & 0x0F));
+ $dec .= chr(0x80 | (($c >> 6) & 0x3F));
+ $dec .= chr(0x80 | (($c >> 0) & 0x3F));
+ }
+ else {
+ $dec .= chr(0xC0 | (($c >> 6) & 0x1F));
+ $dec .= chr(0x80 | (($c >> 0) & 0x3F));
+ }
+ }
+
+ return $dec;
+ }
+
+
+ /**
+ * Convert the data ($str) from RFC 2060's UTF-7 to UTF-8.
+ * If input data is invalid, return the original input string.
+ * RFC 2060 obviously intends the encoding to be unique (see
+ * point 5 in section 5.1.3), so we reject any non-canonical
+ * form, such as &ACY- (instead of &-) or &AMA-&AMA- (instead
+ * of &AMAAwA-).
+ *
+ * Translated from C to PHP by Thomas Bruederli <roundcube@gmail.com>
+ *
+ * @param string $str Input string (UTF7-IMAP)
+ *
+ * @return string Output string (UTF-8)
+ */
+ public static function utf7imap_to_utf8($str)
+ {
+ $Index_64 = array(
+ -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
+ -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
+ -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, 63,-1,-1,-1,
+ 52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
+ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11,12,13,14,
+ 15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
+ -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
+ 41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
+ );
+
+ $u7len = strlen($str);
+ $str = strval($str);
+ $p = '';
+ $err = '';
+
+ for ($i=0; $u7len > 0; $i++, $u7len--) {
+ $u7 = $str[$i];
+ if ($u7 == '&') {
+ $i++;
+ $u7len--;
+ $u7 = $str[$i];
+
+ if ($u7len && $u7 == '-') {
+ $p .= '&';
+ continue;
+ }
+
+ $ch = 0;
+ $k = 10;
+ for (; $u7len > 0; $i++, $u7len--) {
+ $u7 = $str[$i];
+
+ if ((ord($u7) & 0x80) || ($b = $Index_64[ord($u7)]) == -1) {
+ break;
+ }
+
+ if ($k > 0) {
+ $ch |= $b << $k;
+ $k -= 6;
+ }
+ else {
+ $ch |= $b >> (-$k);
+ if ($ch < 0x80) {
+ // Printable US-ASCII
+ if (0x20 <= $ch && $ch < 0x7f) {
+ return $err;
+ }
+ $p .= chr($ch);
+ }
+ else if ($ch < 0x800) {
+ $p .= chr(0xc0 | ($ch >> 6));
+ $p .= chr(0x80 | ($ch & 0x3f));
+ }
+ else {
+ $p .= chr(0xe0 | ($ch >> 12));
+ $p .= chr(0x80 | (($ch >> 6) & 0x3f));
+ $p .= chr(0x80 | ($ch & 0x3f));
+ }
+
+ $ch = ($b << (16 + $k)) & 0xffff;
+ $k += 10;
+ }
+ }
+
+ // Non-zero or too many extra bits
+ if ($ch || $k < 6) {
+ return $err;
+ }
+
+ // BASE64 not properly terminated
+ if (!$u7len || $u7 != '-') {
+ return $err;
+ }
+
+ // Adjacent BASE64 sections
+ if ($u7len > 2 && $str[$i+1] == '&' && $str[$i+2] != '-') {
+ return $err;
+ }
+ }
+ // Not printable US-ASCII
+ else if (ord($u7) < 0x20 || ord($u7) >= 0x7f) {
+ return $err;
+ }
+ else {
+ $p .= $u7;
+ }
+ }
+
+ return $p;
+ }
+
+
+ /**
+ * Convert the data ($str) from UTF-8 to RFC 2060's UTF-7.
+ * Unicode characters above U+FFFF are replaced by U+FFFE.
+ * If input data is invalid, return an empty string.
+ *
+ * Translated from C to PHP by Thomas Bruederli <roundcube@gmail.com>
+ *
+ * @param string $str Input string (UTF-8)
+ *
+ * @return string Output string (UTF7-IMAP)
+ */
+ public static function utf8_to_utf7imap($str)
+ {
+ $B64Chars = array(
+ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
+ 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
+ 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
+ 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
+ '8', '9', '+', ','
+ );
+
+ $u8len = strlen($str);
+ $base64 = 0;
+ $i = 0;
+ $p = '';
+ $err = '';
+
+ while ($u8len) {
+ $u8 = $str[$i];
+ $c = ord($u8);
+
+ if ($c < 0x80) {
+ $ch = $c;
+ $n = 0;
+ }
+ else if ($c < 0xc2) {
+ return $err;
+ }
+ else if ($c < 0xe0) {
+ $ch = $c & 0x1f;
+ $n = 1;
+ }
+ else if ($c < 0xf0) {
+ $ch = $c & 0x0f;
+ $n = 2;
+ }
+ else if ($c < 0xf8) {
+ $ch = $c & 0x07;
+ $n = 3;
+ }
+ else if ($c < 0xfc) {
+ $ch = $c & 0x03;
+ $n = 4;
+ }
+ else if ($c < 0xfe) {
+ $ch = $c & 0x01;
+ $n = 5;
+ }
+ else {
+ return $err;
+ }
+
+ $i++;
+ $u8len--;
+
+ if ($n > $u8len) {
+ return $err;
+ }
+
+ for ($j=0; $j < $n; $j++) {
+ $o = ord($str[$i+$j]);
+ if (($o & 0xc0) != 0x80) {
+ return $err;
+ }
+ $ch = ($ch << 6) | ($o & 0x3f);
+ }
+
+ if ($n > 1 && !($ch >> ($n * 5 + 1))) {
+ return $err;
+ }
+
+ $i += $n;
+ $u8len -= $n;
+
+ if ($ch < 0x20 || $ch >= 0x7f) {
+ if (!$base64) {
+ $p .= '&';
+ $base64 = 1;
+ $b = 0;
+ $k = 10;
+ }
+ if ($ch & ~0xffff) {
+ $ch = 0xfffe;
+ }
+
+ $p .= $B64Chars[($b | $ch >> $k)];
+ $k -= 6;
+ for (; $k >= 0; $k -= 6) {
+ $p .= $B64Chars[(($ch >> $k) & 0x3f)];
+ }
+
+ $b = ($ch << (-$k)) & 0x3f;
+ $k += 16;
+ }
+ else {
+ if ($base64) {
+ if ($k > 10) {
+ $p .= $B64Chars[$b];
+ }
+ $p .= '-';
+ $base64 = 0;
+ }
+
+ $p .= chr($ch);
+ if (chr($ch) == '&') {
+ $p .= '-';
+ }
+ }
+ }
+
+ if ($base64) {
+ if ($k > 10) {
+ $p .= $B64Chars[$b];
+ }
+ $p .= '-';
+ }
+
+ return $p;
+ }
+
+
+ /**
+ * A method to guess character set of a string.
+ *
+ * @param string $string String.
+ * @param string $failover Default result for failover.
+ *
+ * @return string Charset name
+ */
+ public static function detect($string, $failover='')
+ {
+ if (!function_exists('mb_detect_encoding')) {
+ return $failover;
+ }
+
+ // FIXME: the order is important, because sometimes
+ // iso string is detected as euc-jp and etc.
+ $enc = array(
+ 'UTF-8', 'SJIS', 'BIG5', 'GB2312',
+ 'ISO-8859-1', 'ISO-8859-2', 'ISO-8859-3', 'ISO-8859-4',
+ 'ISO-8859-5', 'ISO-8859-6', 'ISO-8859-7', 'ISO-8859-8', 'ISO-8859-9',
+ 'ISO-8859-10', 'ISO-8859-13', 'ISO-8859-14', 'ISO-8859-15', 'ISO-8859-16',
+ 'WINDOWS-1252', 'WINDOWS-1251', 'EUC-JP', 'EUC-TW', 'KOI8-R',
+ 'ISO-2022-KR', 'ISO-2022-JP'
+ );
+
+ $result = mb_detect_encoding($string, join(',', $enc));
+
+ return $result ? $result : $failover;
+ }
+
+
+ /**
+ * Removes non-unicode characters from input.
+ *
+ * @param mixed $input String or array.
+ *
+ * @return mixed String or array
+ */
+ public static function clean($input)
+ {
+ // handle input of type array
+ if (is_array($input)) {
+ foreach ($input as $idx => $val) {
+ $input[$idx] = self::clean($val);
+ }
+ return $input;
+ }
+
+ if (!is_string($input) || $input == '') {
+ return $input;
+ }
+
+ // iconv/mbstring are much faster (especially with long strings)
+ if (function_exists('mb_convert_encoding')) {
+ if (($res = mb_convert_encoding($input, 'UTF-8', 'UTF-8')) !== false) {
+ return $res;
+ }
+ }
+
+ if (function_exists('iconv')) {
+ if (($res = @iconv('UTF-8', 'UTF-8//IGNORE', $input)) !== false) {
+ return $res;
+ }
+ }
+
+ $seq = '';
+ $out = '';
+ $regexp = '/^('.
+// '[\x00-\x7F]'. // UTF8-1
+ '|[\xC2-\xDF][\x80-\xBF]'. // UTF8-2
+ '|\xE0[\xA0-\xBF][\x80-\xBF]'. // UTF8-3
+ '|[\xE1-\xEC][\x80-\xBF][\x80-\xBF]'. // UTF8-3
+ '|\xED[\x80-\x9F][\x80-\xBF]'. // UTF8-3
+ '|[\xEE-\xEF][\x80-\xBF][\x80-\xBF]'. // UTF8-3
+ '|\xF0[\x90-\xBF][\x80-\xBF][\x80-\xBF]'. // UTF8-4
+ '|[\xF1-\xF3][\x80-\xBF][\x80-\xBF][\x80-\xBF]'.// UTF8-4
+ '|\xF4[\x80-\x8F][\x80-\xBF][\x80-\xBF]'. // UTF8-4
+ ')$/';
+
+ for ($i = 0, $len = strlen($input); $i < $len; $i++) {
+ $chr = $input[$i];
+ $ord = ord($chr);
+
+ // 1-byte character
+ if ($ord <= 0x7F) {
+ if ($seq) {
+ $out .= preg_match($regexp, $seq) ? $seq : '';
+ }
+ $seq = '';
+ $out .= $chr;
+ // first (or second) byte of multibyte sequence
+ }
+ else if ($ord >= 0xC0) {
+ if (strlen($seq) > 1) {
+ $out .= preg_match($regexp, $seq) ? $seq : '';
+ $seq = '';
+ }
+ else if ($seq && ord($seq) < 0xC0) {
+ $seq = '';
+ }
+ $seq .= $chr;
+ // next byte of multibyte sequence
+ }
+ else if ($seq) {
+ $seq .= $chr;
+ }
+ }
+
+ if ($seq) {
+ $out .= preg_match($regexp, $seq) ? $seq : '';
+ }
+
+ return $out;
+ }
+
+}