#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/shm.h>
#include <sys/stat.h>

#include <sys/mman.h>
#include <unistd.h>

using namespace std;

const int SIZE{4096};
const string NAME{"/SharedMem"};

int main( int , char ** ) {

    int openFlags { O_RDONLY};
    mode_t mode{ S_IRUSR | S_IWUSR};

    int fd{shm_open(NAME.c_str(), openFlags, mode)};

    if (fd == -1) {
       perror("\tError shm_open: ");
       return 1;
    }

    int protect{ PROT_READ};
    char* basePtr = reinterpret_cast<char *> (
                 mmap(0, SIZE, protect, MAP_SHARED, fd, 0));
    close(fd);
     
    // note to everyone, always read the man page for return type.
    if(basePtr == MAP_FAILED) {
        perror("\tError mmap: ");
    }  else {
        printf("%s\n", (char * ) basePtr);

        int i = 0;
        while (basePtr[i] != 0) {
           cout << char (basePtr[i]) << endl;
           ++i;
        }
        cout << endl;
    }
  
    
    if ( -1 == shm_unlink(NAME.c_str())) {
       perror("\tError shm_unlink: ");
       return 1;
    }
  
    return 0;
    
}