[php] How can I run a PHP script inside a HTML file?

I'm not sure if this is what you wanted, but this is a very hackish way to include php. What you do is you put the php you want to run in another file, and then you include that file in an image. For example:

RunFromHTML.php

<?php
  $file = fopen("file.txt", "w");
  //This will create a file called file.txt,
  //provided that it has write access to your filesystem
  fwrite($file, "Hello World!");
  //This will write "Hello World!" into file.txt
  fclose($file);
  //Always remember to close your files!
?>

RunPhp.html

<html>
  <!--head should be here, but isn't for demonstration's sake-->
  <body>
    <img style="display: none;" src="RunFromHTML.php">
    <!--This will run RunFromHTML.php-->
  </body>
</html>

Now, after visiting RunPhp.html, you should find a file called file.txt in the same directory that you created the above two files, and the file should contain "Hello World!" inside of it.