quote1sub-quote1 post text quote2 post text TXT; $start=0; function step($txt,&$start,$tag=''){ $format='

%2$s

'; $result=''; while(preg_match('//',$txt,$m,PREG_OFFSET_CAPTURE,$start)){ if($start<$m[0][1]){ $result.=substr($txt,$start,$m[0][1]-$start); $start=$m[0][1]; } if($m[1][0]==''){ $start+=strlen($m[0][0]); $result.=step($txt,$start,$m[2][0]); } else { $start+=strlen($m[0][0]); return sprintf($format,$tag,$result); } } return $result.substr($txt,$start,strlen($txt)-$start); } echo step($txt,$start);