php常用的正则过滤

$str=preg_replace("/\s+/", " ", $str); //过滤多余回车   
$str=preg_replace("/<[ ]+/si","<",$str); //过滤<__("<"号后面带空格)   
  
$str=preg_replace("/<\!--.*?-->/si","",$str); //注释   
$str=preg_replace("/<(\!.*?)>/si","",$str); //过滤DOCTYPE   
$str=preg_replace("/<(\/?html.*?)>/si","",$str); //过滤html标签   
$str=preg_replace("/<(\/?head.*?)>/si","",$str); //过滤head标签   
$str=preg_replace("/<(\/?meta.*?)>/si","",$str); //过滤meta标签   
$str=preg_replace("/<(\/?body.*?)>/si","",$str); //过滤body标签   
$str=preg_replace("/<(\/?link.*?)>/si","",$str); //过滤link标签   
$str=preg_replace("/<(\/?form.*?)>/si","",$str); //过滤form标签   
$str=preg_replace("/cookie/si","COOKIE",$str); //过滤COOKIE标签   
  
$str=preg_replace("/<(applet.*?)>(.*?)<(\/applet.*?)>/si","",$str); //过滤applet标签   
$str=preg_replace("/<(\/?applet.*?)>/si","",$str); //过滤applet标签   
  
$str=preg_replace("/<(style.*?)>(.*?)<(\/style.*?)>/si","",$str); //过滤style标签   
$str=preg_replace("/<(\/?style.*?)>/si","",$str); //过滤style标签   
  
$str=preg_replace("/<(title.*?)>(.*?)<(\/title.*?)>/si","",$str); //过滤title标签   
$str=preg_replace("/<(\/?title.*?)>/si","",$str); //过滤title标签   
  
$str=preg_replace("/<(object.*?)>(.*?)<(\/object.*?)>/si","",$str); //过滤object标签   
$str=preg_replace("/<(\/?objec.*?)>/si","",$str); //过滤object标签   
  
$str=preg_replace("/<(noframes.*?)>(.*?)<(\/noframes.*?)>/si","",$str); //过滤noframes标签   
$str=preg_replace("/<(\/?noframes.*?)>/si","",$str); //过滤noframes标签