Because I'm trying to build an OS
I am curious. Why do you want to "build an OS"??
In its full meaning, this would require about 5-10 really expert programmers a year or more.
I presume you really mean you want to use the OS you already have, but would like to develop a menu so you can select stuff you want to do.
Please explain your whole project - the reason for doing it, etc.
Mac