Answers for "how to run php via command line"

run php server

cd path/to/your/app
php -S localhost:8000

cmd run php file

// terminal run php file
// First run "php" in the terminal, in the path directory
php
// If php works there. Then :
php path_to_file/file_name.php

//This will run your php and print stuff to your console in plain text.
//It's useful for a range of testing and data maniplation purposes. 
//And has the full php cammand line. So potential is up to your imagination.