I was just wondering, whether if php can be injected just like the way mysql can be injected. I have a rough idea of how sql injection is done, and have successfully carried it out in development environment. So I was just wondering if php too could be injected. 
Though I myself have a gut feeling that it would not be the case since even if tried it would be more like trying to inject a mysqli prepared statement.
And no! I am not talking about injecting javascript into the input I am talking about plain php-html injection through input/GET/POST . Like stopping the current php code execution and inserting your own code in between. 
 
     
    