OSDev.org

This might be more of a C question but since I only have had this problem when working with OSes I though I could ask it here..
I have a main-file with the main-method...and then I got some IO functions to write/read ports.. works fine..
then I tried to put the in/out functions in a file called IO.c and I included this file in the main-file.. (like you allways do).. but when I try to link I get this message:
kernel.o(.text+0x0):kernel.c: multiple definition of `_out'
io.o(.text+0x0):io.c: first defined here
kernel.o(.text+0x1d):kernel.c: multiple definition of `_in'
io.o(.text+0x1d):io.c: first defined here
I dont know why... I tried to put the "#ifndef.." stuff in the IO file..but it does not work.. when my kernel grows bigger I can have it all in just one file

Sorry, might be reading that wrong.

You included the io.c in kernel.c then tried to link io.c and kernel.c together?

Whoops.. you?re right sorry..
anyways.. I?d like to only include a header with the prototypes..like this
io.h:
extern void in/out..
io.c:
void in ( .. ) {.. }..

in main:
include "io.h"
but I cant get that working