/* 
编程之家  (jb51.cc) 
Utf-8、gb2312都支持的汉字截取函数 
cut_str(字符串,截取长度,开始长度,编码); 
编码默认为 utf-8 
开始长度默认为 0 
*/ 
function cut_str($string,$sublen,$start = 0,$code = 'UTF-8') 
{ 
    if($code == 'UTF-8') 
    { 
        $pa = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|\xe0[\xa0-\xbf][\x80-\xbf]|[\xe1-\xef][\x80-\xbf][\x80-\xbf]|\xf0[\x90-\xbf][\x80-\xbf][\x80-\xbf]|[\xf1-\xf7][\x80-\xbf][\x80-\xbf][\x80-\xbf]/"; 
        preg_match_all($pa,$string,$t_string); 

        if(count($t_string[0]) - $start > $sublen) return join('',array_slice($t_string[0],$start,$sublen))."..."; 
        return join('',$sublen)); 
    } 
    else 
    { 
        $start = $start*2; 
        $sublen = $sublen*2; 
        $strlen = strlen($string); 
        $tmpstr = ''; 

        for($i=0; $i< $strlen; $i++) 
        { 
            if($i>=$start && $i< ($start+$sublen)) 
            { 
                if(ord(substr($string,$i,1))>129) 
                { 
                    $tmpstr.= substr($string,2); 
                } 
                else 
                { 
                    $tmpstr.= substr($string,1); 
                } 
            } 
            if(ord(substr($string,1))>129) $i++; 
        } 
        if(strlen($tmpstr)< $strlen ) $tmpstr.= "..."; 
        return $tmpstr; 
    } 
} 

$str = "abcd需要截取的字符串"; 
echo cut_str($str,8,'gb2312'); 



# End 512.笔记 jb51.cc