How to open PHP files?
When you download a file with php file name extension, it is the fault of the webmaster. There are three possible situations, you can try one by one trying to open the PHP file you downloaded.
Case 1: It is an HTML document generated by PHP
That means it is a webpage file. You can rename it to a .html file extension and open it in a web browser.
Case 2: It is an PHP source code file
You can open it using Notepad/Wordpad or any other text editor programs.
Case 3: It is an PDF/JPG/... document generated by PHP
Similar to case one, it is generated by PHP in the server. But it is not the webpage, it is a different type of file (such as a PDF, executable or graphic) - rename it so the file extension matches the type you were expecting.