#define _XOPEN_SOURCE

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

#define SHM_SIZE 1024  /* make it a 1K shared memory segment */

int main(void)
{

       key_t key;
       int shmid;
       // char *data;
       // int mode;

       /* make the key: */
       if ((key = ftok("test_shm", 'X')) == -1) {
            perror("ftok");
            exit(1);
       }

       /* create the shared memory segment: */
       if ((shmid = shmget(key, SHM_SIZE, 0644 | IPC_CREAT )) == -1) {
            perror("shmget");
            exit(1);
       }

       return(0);
}