php封裝方法字串標點等字元截取不亂碼

<?php   header("Content-type:text/html; charset=utf8");   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, $sublen));    return join('', array_slice($t_string[0], $start, $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, $i, 2);    }    else    {    $tmpstr.= substr($string, $i, 1);    }    }    if(ord(substr($string, $i, 1))>129) $i++;    }    if(strlen($tmpstr)<$strlen ) $tmpstr.= "";    return $tmpstr;    }    }        $str="我slskjd!fl是總那地方展開款到即發";       echo cut_str($str, 8, 5);

