#include <fcntl.h>
#include <unistd.h>
#include <semaphore.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>

int main(void)
{
    int *buff = (int *)malloc(sizeof(int));
    pid_t pid;
    sem_t *sem_empty = sem_open("empty", O_CREAT, 0644, 1), *sem_full = sem_open("full", O_CREAT, 0644, 0);

    pid = fork();
    switch (pid)
    {
        case (-1):
            {
                printf("Failure!\n");
                break;
            }
        case (0):
            {
                sem_wait(sem_empty);
                *buff = 1234;
                sem_post(sem_full);
                break;
            }
        default:
            {
                sem_wait(sem_full);
                printf("%d\n", *buff);
                sem_post(sem_empty);
                break;
            }
    }
    wait(NULL);
    sem_unlink("empty");
    sem_unlink("full");
    return (0);
}