#include <iostream>
#include <stdio.h>    // for perror
#include <unistd.h>   // for gethostbyname
#include <errno.h>    // for errno
#include <string.h>   // for strcpy

using namespace std;

const int BUF_SIZE = 256;

int main() {
    char name[BUF_SIZE];
    int errorSave;

    cout << "This one should be a success " << endl;
    // an example of success
    if (-1 == gethostname(name, BUF_SIZE)) {
        cout << "Failed to get the host name " << endl;
    } else {
        cout << "The host name is " << name << endl;
    }

    cout << endl;

    cout << "This should fail" << endl;
    // try again, but this time, don't admit we have sufficient space.
    if (-1 == gethostname(name, 0)) {
        cout << "Failed to get the host name " << endl;
    } else {
        cout << "The host name is " << name << endl;
    }
    cout << "errno is " << errno << endl;

    cout << endl;

    cout << "Try again, with perror " << endl;
    if (-1 == gethostname(name, 0)) {
        errorSave = errno; 
        perror("gethostbyename failed"); 
	strcpy(name, "UNKNOWN");
    }

    cout << "The host name is " << name << endl;

    // get the error message and display it.
    cout <<"By the way, that error was \"" << strerror(errorSave)
         <<"\"" << endl;

    cout << endl;
    cout << "Just for fun, let's try to set the hostname" << endl;

    if(-1 == sethostname("newname",sizeof("newname")-1) ) {
        perror("sethostname() failed");
    }

    cout << "Drat, knew it!" << endl;


    return  0;
}