I want to find "from tag to closed tag" in the regular expression.

In the following cases, how should I write a regular expression?
There are nearly 100 html files for the purpose of replacing them all at once.

<div class="test">
There are some tags and sentences.It is not constant.
<!--Comments-->
</div>

This is a postscript.Because it is replaced by a tool called devas, it is not particularly Linux or php.
Excuse me.