#include "stdio.h"
#include "sys/ipc.h"
#include "sys/sem.h"
#include "sys/shm.h"
#define true 1
int main() {
  key_t key;
  key = 5555;
  int semafor = semget(key, 1, IPC_CREAT | 0666);
  int shared_segment = shmget(key, 100, IPC_CREAT | 0666);
  char* shared_memory;
  semctl(semafor, 0, SETVAL, 1);
  struct sembuf semlock = { 0, -1, 0 };
  struct sembuf semunlock = { 0, 1, 0 };
  int znak = 0;

  while(true)
  {
    char mess[255];
    znak = getchar();
    if(znak == 49)
    {
      semop(semafor, &semlock, 1);
      printf("Zablokowano! Podaj wiadomość\n");
      shared_memory = (char*) shmat(shared_segment, 0, 0);
      scanf("%s",mess);
      sprintf (shared_memory, mess);
    }
    if(znak == 50)
    {
      shmdt(shared_memory);
      semop(semafor, &semunlock, 1);
      printf("Odblokowano\n");
    }
    if(znak == 120)
    {
      printf("Kończę\n");
      semctl(semafor, 0, IPC_RMID);
      break;
    }
  }

  return 0;
}