shmem

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#define SHMSIZE 1
#define ARRAY_ELEM 10

int main(int argc, char *argv[])
{
    pid_t pid;
    key_t key = ftok(".", 1);
    int shmid = shmget(key, SHMSIZE, IPC_CREAT | 0755);
    char symbol;
    pid = fork();

    if (pid == -1)
    {
        perror("fork");
        exit(EXIT_FAILURE);
    }
    else if (pid == 0) //child -> producer
    {
        char *buff = shmat(shmid, NULL, 0);
        for (symbol = 'a'; symbol <= 'z'; symbol++)
        {
            usleep(500);
            *buff = symbol;
            usleep(500);
        }
        shmdt(buff);
    }
    else if (pid > 0) //parent -> consumer
    {
        int i;
        char *buff = shmat(shmid, 0, 0);
        for (int i = 0; i <= 'z' - 'a'; i++)
        {
            usleep(500);
            symbol = *buff;
            printf("%d Received symbol %c\n", (i+1), symbol);
            usleep(500);
        }
        shmdt(buff);
        wait(NULL);
        shmctl(shmid, IPC_RMID, NULL);
    }
    return 0;
}