我們常常會用到PHP過濾一些標簽的功能，比如過濾鏈接標簽、過濾script標簽等等，下面就介紹一下PHP過濾常用標簽的正則表達式代碼：
復制代碼代碼如下:
$str=preg_replace("//s+/", " ", $str); //過濾多余回車
$str=preg_replace("/<[ ]+/si","<",$str); //過濾<__("<"號后面帶空格)
$str=preg_replace("/</!–.*?–>/si","",$str); //注釋
$str=preg_replace("/<(/!.*?)>/si","",$str); //過濾DOCTYPE
$str=preg_replace("/<(//?html.*?)>/si","",$str); //過濾html標簽
$str=preg_replace("/<(//?head.*?)>/si","",$str); //過濾head標簽
$str=preg_replace("/<(//?meta.*?)>/si","",$str); //過濾meta標簽
$str=preg_replace("/<(//?body.*?)>/si","",$str); //過濾body標簽
$str=preg_replace("/<(//?link.*?)>/si","",$str); //過濾link標簽
$str=preg_replace("/<(//?form.*?)>/si","",$str); //過濾form標簽
$str=preg_replace("/cookie/si","COOKIE",$str); //過濾COOKIE標簽
$str=preg_replace("/<(applet.*?)>(.*?)<(//applet.*?)>/si","",$str); //過濾applet標簽
$str=preg_replace("/<(//?applet.*?)>/si","",$str); //過濾applet標簽
$str=preg_replace("/<(style.*?)>(.*?)<(//style.*?)>/si","",$str); //過濾style標簽
$str=preg_replace("/<(//?style.*?)>/si","",$str); //過濾style標簽
$str=preg_replace("/<(title.*?)>(.*?)<(//title.*?)>/si","",$str); //過濾title標簽
$str=preg_replace("/<(//?title.*?)>/si","",$str); //過濾title標簽
$str=preg_replace("/<(object.*?)>(.*?)<(//object.*?)>/si","",$str); //過濾object標簽
$str=preg_replace("/<(//?objec.*?)>/si","",$str); //過濾object標簽
$str=preg_replace("/<(noframes.*?)>(.*?)<(//noframes.*?)>/si","",$str); //過濾noframes標簽
$str=preg_replace("/<(//?noframes.*?)>/si","",$str); //過濾noframes標簽
$str=preg_replace("/<(i?frame.*?)>(.*?)<(//i?frame.*?)>/si","",$str); //過濾frame標簽
$str=preg_replace("/<(//?i?frame.*?)>/si","",$str); //過濾frame標簽
$str=preg_replace("/<(script.*?)>(.*?)<(//script.*?)>/si","",$str); //過濾script標簽
$str=preg_replace("/<(//?script.*?)>/si","",$str); //過濾script標簽
$str=preg_replace("/javascript/si","Javascript",$str); //過濾script標簽
$str=preg_replace("/vbscript/si","Vbscript",$str); //過濾script標簽
$str=preg_replace("/on([a-z]+)/s*=/si","On//1=",$str); //過濾script標簽
$str=preg_replace("/&#/si","&＃",$str); //過濾script標簽
