PHP in Windows, under IIS and Apache, file path is handled differently

PHP in Windows, under IIS and Apache, file path is handled differently, for example:

Under IIS:
C:\Projects\test.php

Under Apache:
C:/Projects/test.php

So if you want based on “/” to do something like RegEx, remember convert Windows style file path to Unix style, e.g:

Then your PHP will run cross platform either in Windows IIS or Apache, or Linux.