关于正则的贪心匹配与换行符匹配

最近做一个问题,去除html中代码的JS脚本,代码如下

 1 <?php
 2     $text = <<<EOF
 3     ilove you
 4     <scrip></sss>
 5     <script> ok </script>
 6     kkyz <dd>m,dfd
 7     <script>
 8         sdfsdf
 9     </script>
10     <script> no </script>
11     ook
12 EOF;
13 
14     echo "orginal text: \n\n" . $text . "\n\n";
15     $pattern1 = "@<script.*?>(.*?)</script>@is";    #等效于"@<script.*>(.*)</script>@isU"
16     #末尾的i表示忽略大小写,s表示.可以匹配换行符,U与?等效,表示关闭无限匹配
17     $pattern2 = "@<script.*>(.*)</script>@is";    #这是无限匹配的pattern,php默认就是无限匹配
18     $text1 = preg_replace($pattern1, "", $text);
19     $text2 = preg_replace($pattern2, "", $text);
20     echo "text1: \n\n" . $text1 . "\n\n";
21     echo "text2: \n\n" . $text2 . "\n\n";
22 ?>

 

结果如下: