如果字符串有php开启标记，php字符串将中断

My code is below

<?php echo '6p]<?mSKPQ'; ?>

Above code showing result like below

6p]

But I need like below

6p]<?mSKPQ

So what should I do for avoid to break string if string have php opening tag.

echo htmlspecialchars('6p]<?mSKPQ');

Live Example. https://eval.in/924127

And Before Asking this type of question please read What is the difference between single-quoted and double-quoted strings in PHP