PHP and SSI

How would I include a PHP file in a .shtml file, or vice-versa?

I kind of asked this question a few days ago, but nobody answered... I did look in the PHP manual and FAQ, but I didn't find anything...

Sure,

You can use a .shtml file or similar from
PHP using the "virtual" function:

virtual( "file.shtml");

which by making an Apache sub-requests
returns the SSI parsed result and includes
it in the PHP script.

For documentation on "virtual goto:"

There's a small glitch: the function changes
the directory so you have to be aware,
there's a workaround also in the commented
documentation.

Luis