1.strip_tags(剥去字符串中的 HTML 标签)

strip_tags() 函数剥去字符串中的 HTML、XML 以及 PHP 的标签。

 

2.字符串替换

str_replace(array(" "," ","\t","\r\n","\r","\n"),array("","","","","","")

 

3.利用正则表达式(效率稍微低一些)

$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

$str=preg_replace("/<(i?frame.*?)>(.*?)<(\/i?frame.*?)>/si","",$str); //过滤frame标签

$str=preg_replace("/<(\/?i?frame.*?)>/si","",$str); //过滤frame标签

$str=preg_replace("/<(script.*?)>(.*?)<(\/script.*?)>/si","",$str); //过滤script标签

$str=preg_replace("/<(\/?script.*?)>/si","",$str); //过滤script标签

$str=preg_replace("/javascript/si","Javascript",$str); //过滤script标签

$str=preg_replace("/vbscript/si","Vbscript",$str); //过滤script标签

$str=preg_replace("/on([a-z]+)\s*=/si","On\\1=",$str); //过滤script标签

$str=preg_replace("/&#/si","&＃",$str); //过滤script标签，如javAsCript:alert(