Replacing SSIs with PHP

How would I go about it?

[universetoday]

I know that you can have the same functionality with PHP to perform server side includes (SSIs). I've heard that suggestion from many people that I should consider switching over to PHP. The problem is that I've got a very large website with literally thousands of pages which are interlinked and indexed by Google. Is there a way that I can use PHP includes but still maintain my existing filenames?

[bibby]

To make use of PHP, a page would require a .php filename.

[abbeyvet]

To make use of PHP, a page would require a .php filename.

No, all you need to do is make sure the server can parse php in files with a .html extension or whatever extension you like. You can ask your host to set this up or do it yourself using .htaccess

I've heard that suggestion from many people that I should consider switching over to PHP.

If all you will be doing is replacing SSI includes with PHP includes that would be fairly pointless.

If you need to use php for some other reason it's a different thing, but for includes it's pretty much 6 of one and half a dozen of the other.

[universetoday]

There would be other advantages, it would allow me to run PHP scripts inside my various pages, so it wouldn't be just to run the same functionality of SSIs.

What would I actually put into my .htaccess file?

[jatar_k]

try this
Parsing PHP with HTML file extension [webmasterworld.com]