// To pass one function to another, one might say
int f(void);
/* ... */
g(f);

// Then the definition of g might read
void g(int (*funcp)(void))
{
    /* ... */
    (*funcp)(); /* or funcp(); ... */
}

// or, equivalently,
void g(int func(void))
{
    /* ... */
    func(); /* or (*func)(); ... */
}