preg_replace("/([u4e00-u9fa5])/","",$str);

function check_is_chinese($s){

return preg_match('/[\x80-\xff]./', $s);

}

//获取字符串长度-GBK(PHP)

function gb_strlen($str){

$count = 0;

for($i=0; $i<strlen($str); $i++){

$s = substr($str, $i, 1);

if (preg_match("/[\x80-\xff]/", $s)) ++$i;

++$count;

}

return $count;

}

//截取字符串字串-GBK(PHP)

function gb_substr($str, $len){

$count = 0;

for($i=0; $i<strlen($str); $i++){

if($count == $len) break;

if(preg_match("/[\x80-\xff]/", substr($str, $i, 1))) ++$i;

++$count;

}

return substr($str, 0, $i);

}

//统计字符串长度-UTF8(PHP)

function utf8_strlen($str) {

$count = 0;

for($i = 0; $i <strlen($str); $i++){

$value = ord($str[$i]);

if($value > 127) {

$count++;

if($value >= 192 && $value <= 223) $i++;

elseif($value >= 224 && $value <= 239) $i = $i + 2;

elseif($value >= 240 && $value <= 247) $i = $i + 3;

else die('Not a UTF-8 compatible string');

}

$count++;

}

return $count;

}

//截取字符串-UTF8(PHP)

function utf8_substr($str,$position,$length){

$start_position = strlen($str);

$start_byte = 0;

$end_position = strlen($str);

$count = 0;

for($i = 0; $i <strlen($str); $i++){

if($count >= $position && $start_position > $i){

$start_position = $i;

$start_byte = $count;

}

if(($count-$start_byte) >= $length) {

$end_position = $i;

break;

}

$value = ord($str[$i]);

if($value > 127){

$count++;

if($value >= 192 && $value <= 223) $i++;

elseif($value >= 224 && $value <= 239) $i = $i + 2;

elseif($value >= 240 && $value <= 247) $i = $i + 3;

else die('Not a UTF-8 compatible string');

}

$count++;

}

return(substr($str,$start_position,$end_position-$start_position));

}

//字符串长度统计-UTF8[中文占3个字节，俄文、韩文占2个字节，字母占1个字节](Ruby)

def utf8_string_length(str)

temp = CGI::unescape(str)

i = 0;

j = 0;

temp.length.times{|t|

if temp[t] < 127

i += 1

elseif temp[t] >= 127 and temp[t] <224

j += 1

if 0 == (j % 2)

i += 2

j = 0

end

else

j += 1

if 0 == (j % 3)

i +=2

j = 0

end

end

}

return i

}

//判断是否是有韩文-UTF-8(javascript)

function checkKoreaChar(str) {

for(i = 0; i < str.length; i++) {

if(((str.charCodeAt(i) > 0x3130 && str.charCodeAt(i) < 0x318F) || (str.charCodeAt(i) >= 0xAC00 && str.charCodeAt(i) <= 0xD7A3))) {

return true;

}

}

return false;

}

//判断是否有中文字符-GBK(javascript)

function check_chinese_char(s){

return (s.length != s.replace(/[^\x00-\xff]/g,"**").length);

}