PHP 中国語インターセプト文字列関数 (非常に便利)

/**
* 中国語文字列インターセプト関数
* by bbs.it-home.org
*/
function Cut_str($string,$sublen,$filter=true,$start=0,$code='UTF-8 '){
 if($filter) $string=Html2Text($string);
 if($code=='UTF-8'){
 $pa="/[x01-x7f]|[xc2-xdf][ x80-xbf]|[xe0-xef][x80-xbf]{2}|[xf0-xff][x80-xbf]{3}/";
 preg_match_all($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 $tmpstr;
 }
}
//html转换関数
function Html2Text($str){
 $str = preg_replace("/||/isU","",$str);
 $alltext = "";
 $ start = 1;
 for($i=0;$i if($start==0 && $str[$i]==">"){
 $ start = 1;
 }else if($start==1){
 if($str[$i]=="<"){
 $start = 0;
 $alltext .= " ";
 }else if(ord($str[$i])>31){
 $alltext .= $str[$i];
 }
 }
 }
 $alltext = str_replace(" "," ",$alltext);
 $alltext = preg_replace("/&([^;&]*)(;|&)/","",$alltext);
 $alltext = preg_replace("/[ ]+/s"," ", $alltext);
 return $alltext;
}