#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdint>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>

#define SHM_KEY 1234

using namespace std;

void *attach_shared_memory(size_t& shm_bytes) {
        int shmid=shmget(SHM_KEY,1,0666);
        if(shmid==-1){
                cout<< "Attach memory failed" << endl;
                _exit(1);
        }
        void *base=shmat(shmid,NULL,0);
        return base;
}

int main(void){
        size_t l=1000;
        size_t n=640;

        size_t shm_bytes=l*n*n*sizeof(uint8_t);
        void*base=attach_shared_memory(shm_bytes);
        uint8_t *a=(uint8_t*)base;
        for(int i=0;i<n;i++){
                cout << (unsigned int) a[i] << "";
        }
        cout << endl;

        return 0;
}