只是把这里作为替代（本质上有点复杂），wordpress 使用这个功能来去除重音。在下面进行了一些更改，使其在不引用 wordpress 函数的情况下独立运行。
function mbstring_binary_safe_encoding($reset = false)
{
static $encodings = array();
static $overloaded = null;
if (is_null($overloaded)) {
$overloaded = function_exists('mb_internal_encoding') && (ini_get('mbstring.func_overload') & 2);
}
if (false === $overloaded) {
return;
}
if (!$reset) {
$encoding = mb_internal_encoding();
array_push($encodings, $encoding);
mb_internal_encoding('ISO-8859-1');
}
if ($reset && $encodings) {
$encoding = array_pop($encodings);
mb_internal_encoding($encoding);
}
}
function seems_utf8($str)
{
mbstring_binary_safe_encoding();
$length = strlen($str);
mbstring_binary_safe_encoding(true);
for ($i = 0; $i < $length; $i++) {
$c = ord($str[$i]);
if ($c < 0x80) {
$n = 0;
}
// 0bbbbbbb
elseif (($c & 0xE0) == 0xC0) {
$n = 1;
}
// 110bbbbb
elseif (($c & 0xF0) == 0xE0) {
$n = 2;
}
// 1110bbbb
elseif (($c & 0xF8) == 0xF0) {
$n = 3;
}
// 11110bbb
elseif (($c & 0xFC) == 0xF8) {
$n = 4;
}
// 111110bb
elseif (($c & 0xFE) == 0xFC) {
$n = 5;
}
// 1111110b
else {
return false;
}
// Does not match any model
for ($j = 0; $j < $n; $j++) {
// n bytes matching 10bbbbbb follow ?
if ((++$i == $length) || ((ord($str[$i]) & 0xC0) != 0x80)) {
return false;
}
}
}
return true;
}
function remove_accents($string)
{
if (!preg_match('/[\x80-\xff]/', $string)) {
return $string;
}
if (seems_utf8($string)) {
$chars = array(
// Decompositions for Latin-1 Supplement
'ª' => 'a', 'º' => 'o',
'À' => 'A', 'Á' => 'A',
'Â' => 'A', 'Ã' => 'A',
'Ä' => 'A', 'Å' => 'A',
'Æ' => 'AE', 'Ç' => 'C',
'È' => 'E', 'É' => 'E',
'Ê' => 'E', 'Ë' => 'E',
'Ì' => 'I', 'Í' => 'I',
'Î' => 'I', 'Ï' => 'I',
'Ð' => 'D', 'Ñ' => 'N',
'Ò' => 'O', 'Ó' => 'O',
'Ô' => 'O', 'Õ' => 'O',
'Ö' => 'O', 'Ù' => 'U',
'Ú' => 'U', 'Û' => 'U',
'Ü' => 'U', 'Ý' => 'Y',
'Þ' => 'TH', 'ß' => 's',
'à' => 'a', 'á' => 'a',
'â' => 'a', 'ã' => 'a',
'ä' => 'a', 'å' => 'a',
'æ' => 'ae', 'ç' => 'c',
'è' => 'e', 'é' => 'e',
'ê' => 'e', 'ë' => 'e',
'ì' => 'i', 'í' => 'i',
'î' => 'i', 'ï' => 'i',
'ð' => 'd', 'ñ' => 'n',
'ò' => 'o', 'ó' => 'o',
'ô' => 'o', 'õ' => 'o',
'ö' => 'o', 'ø' => 'o',
'ù' => 'u', 'ú' => 'u',
'û' => 'u', 'ü' => 'u',
'ý' => 'y', 'þ' => 'th',
'ÿ' => 'y', 'Ø' => 'O',
// Decompositions for Latin Extended-A
'Ā' => 'A', 'ā' => 'a',
'Ă' => 'A', 'ă' => 'a',
'Ą' => 'A', 'ą' => 'a',
'Ć' => 'C', 'ć' => 'c',
'Ĉ' => 'C', 'ĉ' => 'c',
'Ċ' => 'C', 'ċ' => 'c',
'Č' => 'C', 'č' => 'c',
'Ď' => 'D', 'ď' => 'd',
'Đ' => 'D', 'đ' => 'd',
'Ē' => 'E', 'ē' => 'e',
'Ĕ' => 'E', 'ĕ' => 'e',
'Ė' => 'E', 'ė' => 'e',
'Ę' => 'E', 'ę' => 'e',
'Ě' => 'E', 'ě' => 'e',
'Ĝ' => 'G', 'ĝ' => 'g',
'Ğ' => 'G', 'ğ' => 'g',
'Ġ' => 'G', 'ġ' => 'g',
'Ģ' => 'G', 'ģ' => 'g',
'Ĥ' => 'H', 'ĥ' => 'h',
'Ħ' => 'H', 'ħ' => 'h',
'Ĩ' => 'I', 'ĩ' => 'i',
'Ī' => 'I', 'ī' => 'i',
'Ĭ' => 'I', 'ĭ' => 'i',
'Į' => 'I', 'į' => 'i',
'İ' => 'I', 'ı' => 'i',
'IJ' => 'IJ', 'ij' => 'ij',
'Ĵ' => 'J', 'ĵ' => 'j',
'Ķ' => 'K', 'ķ' => 'k',
'ĸ' => 'k', 'Ĺ' => 'L',
'ĺ' => 'l', 'Ļ' => 'L',
'ļ' => 'l', 'Ľ' => 'L',
'ľ' => 'l', 'Ŀ' => 'L',
'ŀ' => 'l', 'Ł' => 'L',
'ł' => 'l', 'Ń' => 'N',
'ń' => 'n', 'Ņ' => 'N',
'ņ' => 'n', 'Ň' => 'N',
'ň' => 'n', 'ʼn' => 'n',
'Ŋ' => 'N', 'ŋ' => 'n',
'Ō' => 'O', 'ō' => 'o',
'Ŏ' => 'O', 'ŏ' => 'o',
'Ő' => 'O', 'ő' => 'o',
'Œ' => 'OE', 'œ' => 'oe',
'Ŕ' => 'R', 'ŕ' => 'r',
'Ŗ' => 'R', 'ŗ' => 'r',
'Ř' => 'R', 'ř' => 'r',
'Ś' => 'S', 'ś' => 's',
'Ŝ' => 'S', 'ŝ' => 's',
'Ş' => 'S', 'ş' => 's',
'Š' => 'S', 'š' => 's',
'Ţ' => 'T', 'ţ' => 't',
'Ť' => 'T', 'ť' => 't',
'Ŧ' => 'T', 'ŧ' => 't',
'Ũ' => 'U', 'ũ' => 'u',
'Ū' => 'U', 'ū' => 'u',
'Ŭ' => 'U', 'ŭ' => 'u',
'Ů' => 'U', 'ů' => 'u',
'Ű' => 'U', 'ű' => 'u',
'Ų' => 'U', 'ų' => 'u',
'Ŵ' => 'W', 'ŵ' => 'w',
'Ŷ' => 'Y', 'ŷ' => 'y',
'Ÿ' => 'Y', 'Ź' => 'Z',
'ź' => 'z', 'Ż' => 'Z',
'ż' => 'z', 'Ž' => 'Z',
'ž' => 'z', 'ſ' => 's',
// Decompositions for Latin Extended-B
'Ș' => 'S', 'ș' => 's',
'Ț' => 'T', 'ț' => 't',
// Euro Sign
'€' => 'E',
// GBP (Pound) Sign
'£' => '',
// Vowels with diacritic (Vietnamese)
// unmarked
'Ơ' => 'O', 'ơ' => 'o',
'Ư' => 'U', 'ư' => 'u',
// grave accent
'Ầ' => 'A', 'ầ' => 'a',
'Ằ' => 'A', 'ằ' => 'a',
'Ề' => 'E', 'ề' => 'e',
'Ồ' => 'O', 'ồ' => 'o',
'Ờ' => 'O', 'ờ' => 'o',
'Ừ' => 'U', 'ừ' => 'u',
'Ỳ' => 'Y', 'ỳ' => 'y',
// hook
'Ả' => 'A', 'ả' => 'a',
'Ẩ' => 'A', 'ẩ' => 'a',
'Ẳ' => 'A', 'ẳ' => 'a',
'Ẻ' => 'E', 'ẻ' => 'e',
'Ể' => 'E', 'ể' => 'e',
'Ỉ' => 'I', 'ỉ' => 'i',
'Ỏ' => 'O', 'ỏ' => 'o',
'Ổ' => 'O', 'ổ' => 'o',
'Ở' => 'O', 'ở' => 'o',
'Ủ' => 'U', 'ủ' => 'u',
'Ử' => 'U', 'ử' => 'u',
'Ỷ' => 'Y', 'ỷ' => 'y',
// tilde
'Ẫ' => 'A', 'ẫ' => 'a',
'Ẵ' => 'A', 'ẵ' => 'a',
'Ẽ' => 'E', 'ẽ' => 'e',
'Ễ' => 'E', 'ễ' => 'e',
'Ỗ' => 'O', 'ỗ' => 'o',
'Ỡ' => 'O', 'ỡ' => 'o',
'Ữ' => 'U', 'ữ' => 'u',
'Ỹ' => 'Y', 'ỹ' => 'y',
// acute accent
'Ấ' => 'A', 'ấ' => 'a',
'Ắ' => 'A', 'ắ' => 'a',
'Ế' => 'E', 'ế' => 'e',
'Ố' => 'O', 'ố' => 'o',
'Ớ' => 'O', 'ớ' => 'o',
'Ứ' => 'U', 'ứ' => 'u',
// dot below
'Ạ' => 'A', 'ạ' => 'a',
'Ậ' => 'A', 'ậ' => 'a',
'Ặ' => 'A', 'ặ' => 'a',
'Ẹ' => 'E', 'ẹ' => 'e',
'Ệ' => 'E', 'ệ' => 'e',
'Ị' => 'I', 'ị' => 'i',
'Ọ' => 'O', 'ọ' => 'o',
'Ộ' => 'O', 'ộ' => 'o',
'Ợ' => 'O', 'ợ' => 'o',
'Ụ' => 'U', 'ụ' => 'u',
'Ự' => 'U', 'ự' => 'u',
'Ỵ' => 'Y', 'ỵ' => 'y',
// Vowels with diacritic (Chinese, Hanyu Pinyin)
'ɑ' => 'a',
// macron
'Ǖ' => 'U', 'ǖ' => 'u',
// acute accent
'Ǘ' => 'U', 'ǘ' => 'u',
// caron
'Ǎ' => 'A', 'ǎ' => 'a',
'Ǐ' => 'I', 'ǐ' => 'i',
'Ǒ' => 'O', 'ǒ' => 'o',
'Ǔ' => 'U', 'ǔ' => 'u',
'Ǚ' => 'U', 'ǚ' => 'u',
// grave accent
'Ǜ' => 'U', 'ǜ' => 'u',
);
$string = strtr($string, $chars);
} else {
$chars = array();
// Assume ISO-8859-1 if not UTF-8
$chars['in'] = "\x80\x83\x8a\x8e\x9a\x9e"
. "\x9f\xa2\xa5\xb5\xc0\xc1\xc2"
. "\xc3\xc4\xc5\xc7\xc8\xc9\xca"
. "\xcb\xcc\xcd\xce\xcf\xd1\xd2"
. "\xd3\xd4\xd5\xd6\xd8\xd9\xda"
. "\xdb\xdc\xdd\xe0\xe1\xe2\xe3"
. "\xe4\xe5\xe7\xe8\xe9\xea\xeb"
. "\xec\xed\xee\xef\xf1\xf2\xf3"
. "\xf4\xf5\xf6\xf8\xf9\xfa\xfb"
. "\xfc\xfd\xff";
$chars['out'] = "EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy";
$string = strtr($string, $chars['in'], $chars['out']);
$double_chars = array();
$double_chars['in'] = array("\x8c", "\x9c", "\xc6", "\xd0", "\xde", "\xdf", "\xe6", "\xf0", "\xfe");
$double_chars['out'] = array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th');
$string = str_replace($double_chars['in'], $double_chars['out'], $string);
}
return $string;
}