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: