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

main() {
    key_t key = 15;
    int shmid_1, shmid_2;
    if ((shmid_1 = shmget(key, 1000, 0644 | IPC_CREAT)) == -1) {
        perror("shmget shmid_1");
        exit(1);
    }
    printf("First shared memory identifier is %d\n", shmid_1);
    if ((shmid_2 = shmget(IPC_PRIVATE, 20, 0644)) == -1) {
        perror("shmget shmid_2");
        exit(2);
    }
    printf("Second shared memory identifier is %d\n", shmid_2);
    exit(0);
}