The C Programming Language - Pointers

1.11 Return a Pointer from Functions
You already know how to declare functions with return values. If the return value is a
pointer, a * is appended to the return type as usual.
int* func() {
…
}
In the following example, the address of ivar is returned as the return value:
/* example 139 - return a pointer from functions */
#include
int* myFunction(void) {
static int ivar = 100; // declare here a static variable
}
return (&ivar); // return the address of ivar
int main (void)
{
int *iptr;
iptr = myFunction();
// function call, iptr get the address of ivar
printf("Address of ivar: %p\n", iptr);
printf("Value of ivar: %d\n", *iptr);
*iptr = 50; // change the value of ivar to 50
printf("Value of ivar: %d\n", *iptr);
}
return 0;
Address of ivar: 0040a004
Value of ivar: 100
Value of ivar: 50
It is important that the variable within the function is defined as a static variable,
otherwise it will be destroyed when the function is exited and access to this address is
no longer possible.
The C Programming Language by Heimo Gaicher – Chapter Pointers 22