#include <iostream>

#include <unistd.h>  // get/set hostname
#include <limits.h>   // for HOST_NAME_MAX

#include <stdio.h>    // perror
#include <errno.h>    //errorno

using namespace std;

const int LEN = HOST_NAME_MAX;

int main() {
     char name[LEN];

     gethostname(name, LEN);
     cout << "The host name is " << name << endl;

     return 0;
}