#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/shm.h>
#include <sys/mman.h>
#include <unistd.h>
#include <sys/types.h>

int main()
{
    //Size in bytes of the shared memory structure
    const int SIZE = 4096;

    //Name of the shared memory struct
    const char * name = "SHMEM";

    //Messages to write to shared memory
    const char * message_1 = "Hello";
    const char * message_2 = "There";

    //File descriptor for shared memory file
    int fd_shm;

    //Void pointer that points to the shared memory struct
    void * shm_ptr;

    //Create shmem object using the shm_open function
    fd_shm = shm_open(name, O_CREAT | O_RDWR, 0666);

    //Set the size of the shared memory object
    ftruncate(fd_shm, SIZE);

    //Memory map the shared struct.
    shm_ptr = mmap(0, SIZE, PROT_WRITE, MAP_SHARED, fd_shm, 0);

    //Write to the shared memory struct.
    sprintf(shm_ptr, "%s", message_1);
    shm_ptr = shm_ptr + strlen(message_1);

    sprintf(shm_ptr, "%s", message_2);
    shm_ptr = shm_ptr + strlen(message_2);

    return 0;
}