#include <iostream>

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

#include <stdio.h>   // perror
#include <errno.h>   // errno
#include <string.h>  // strerror

using namespace std;

const int LEN = HOST_NAME_MAX;

int main() {
     char name[LEN];
     char eName[1];
     int errorNum;
     char * errorMessage;

     if (0 != gethostname(eName, 1)) {
         errorNum = errno;
	 errorMessage = strerror(errorNum);
	 cerr << "\tThe call to gethostname failed" << endl ;
	 cerr << "\tThe system says " << errorMessage << endl;
     }

     return 0;
}