C :: Program That Displays Menu Of Commands For User To Choose From

I've read that we can write a program that displays a menu of commands for the user to choose from.We can write some functions that implement these commands, then store pointers to the functions in the array :

Code:
void ( *file_cmd[])(void) = { new_cmd , open_cmd }; // 2 cmd's for simplicity

We can get a similar effect with a switch statement but using an array of function pointers gives us more flexibility since the elements of the array can be changed as the programm is running.

I decided to write an example about this in order to understand better the context, I am facing some problems though :

Code:
#include<stdio.h>
#include<stdlib.h>
typedef void (*p_foo) (int);
void foo(int x);
void foo2(int y);

[Code] .....

The problems are :

Code:
TEST2.c:9: warning: initialization from incompatible pointer type
TEST2.c:9: warning: initialization from incompatible pointer type
TEST2.c:25: error: too few arguments to function "*(arr + (long unsigned int)((long unsigned int)i * 8ul))"