I have a file named "change_directoryName.php".
There is a directory named "old_directoryName" in the directory.

I like to put some code into the file "change_directoryName.php" for changing the directory name from "old_directoryName" to "new_directoryName".

The would-be code below doesn't work correctly, but I hope it shows what I want to try,
would-be code

change_directoryName("old_directoryName", "new_directoryName");