getHostByName.c

#include <stdlib.h>
#include <stdio.h>
#include <netdb.h>
#include <sys/socket.h>

#include <arpa/inet.h>
#include <netinet/in.h>

int main(int argc, char* argv[])
{
	struct hostent *host_descriptor;
	char *address = argv[1];

	host_descriptor = gethostbyname(address);
	if(host_descriptor == NULL)
	{
		perror("[ADR] host_descriptor is NULL\n");
		return -1;
	}

	printf("[ADR] succesfully received information from %s\n", address);
	printf("[ADR] official name of the host is %s (%s)\n", host_descriptor->h_name, inet_ntoa(*(struct in_addr *)host_descriptor->h_addr));

	for(int i = 0; host_descriptor->h_aliases[i] != NULL; i++)
	{
		printf("      + alternative hostname is %s (%s)\n", host_descriptor->h_aliases[i], inet_ntoa(* (struct in_addr *)host_descriptor->h_addr_list[i]));
	}


	return 0;
}