function pointer in c

gistfile1.c

// this code will run mode_one once, then mode_two forever.

#include <stdio.h>

// a pointer to the mode you want to call
void (*modePtr)();

// function prototypes
void mode_one();
void mode_two();

// modes
void mode_one(void)
{
  printf("running mode one");

  // change mode pointer to a different function
  modePtr = mode_two;
}

void mode_two(void)
{
  printf("running mode two");
}

void main(void)
{

  // set mode pointer to mode one
  mode_pointer = mode_one;

  while(1)
  {
    // run whatever function the mode pointer is currently pointing to
    modePtr();
  }

}

// so, anywhere you have stuff like mode = ENTERING_LOCKOUT you'll change it to
// mode = entering_lockout_mode (the function that actually gets called as a result)
// instead of setting the mode to a number that the mainline has to run through a
// switch statement to find a function for, you're setting the mode to the function itself