read port RB7 or other port from PICF184550 in program language C

I'm using the picdem F184550, I want to read the value of the led, I'm using the mplab ide v8.63 with a C compiler. but I don't have a idea how to interface with the port RB7 where my led with a resis开发者_如何学Pythontor is connected to. The question is, how can I read the port RB7 where my led is connected to in the program language C. thanks! (see picture

This depends on the compiling suite you are using.

Those provided by Microchip (C18 for 18F MCUs) usually define all available ports & registers in a header file specific to your device (something like p18F4550.h in your case).

In this header, you will have a structure definition corresponding to your specific port register. You can access to your specific RB7 I/O,within the following field : PORTBbits.RB7