#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/shm.h>

int main()
{ char s[100];
  int key = ftok("share.c", 1);
  printf("key = %d\n", key);
  int id = shmget(key, 1024, 0777 | IPC_CREAT);
  printf("id = %d\n", id);

  void * ptr = shmat(id, (void *)0x800000, 0);
  printf("address is %016llX\n", ptr);
  int * array = (int *)ptr;
  int * other = 10 + (int *)ptr;    // for example

  printf("array[0] = %d\n", array[0]);
  array[0] += 111;
  printf("array[0] = %d\n", array[0]);

  fgets(s, 99, stdin);

  array[0] += 111;
  printf("array[0] = %d\n", array[0]);
  array[0] += 111;
  printf("array[0] = %d\n", array[0]);

  int r = shmdt(ptr);
  printf("shmdt r = %d\n", r);
  r = shmctl(id, IPC_RMID, NULL);
  printf("shmctl r = %d\n", r); }