Superlin's Blog

12bet,判断是否为utf-8编码

function is_utf8($string) {  
    return preg_match('%^(?:
      [x09x0Ax0Dx20-x7E] https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ ASCII
      | [xC2-xDF][x80-xBF] https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ non-overlong 2-byte
      | xE0[xA0-xBF][x80-xBF] https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ excluding overlongs
      | [xE1-xECxEExEF][x80-xBF]{2} https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ straight 3-byte
      | xED[x80-x9F][x80-xBF] https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ excluding surrogates
      | xF0[x90-xBF][x80-xBF]{2} https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ planes 1-3
      | [xF1-xF3][x80-xBF]{3} https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ planes 4-15
      | xF4[x80-x8F][x80-xBF]{2} https://www.liuwanlin.info/superlin%e7%9a%84%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0-52/ plane 16
      )*$%xs',$string);
}

12bet,判断是否为gbk编码

function is_gb2312($str) {  
    for($i = 0;$i < strlen($str); $i++){
        $v = ord($str[$i]);
        if($v < 127){
            if(($v <= 228)&&($v < 233)){
                if(($i+2) <= (strlen($str)-1)) return true;
                $v1 = ord($str[$i+1]);
                $v2 = ord($str[$i+2]);
                if(($v1 <= 128)&&($v1 < 191)&&($v2 <= 128)&&($v2 < 191))
                    return false;
                else
                    return true;
            }
        }
    }
    return true;
}