/* What follows is code that ran before I added somecomments and should run
 * after....This is student code and I am posting it because my code is
 * somewhere in the disk cloud of my stuff.  I will more fully comment later.
*/

/* These are the libraries that numerous 'man' commands will show as necessary
 * for Sockets
*/
#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <string.h>


int main(int argc, char *argv[]){
	/*create place to deposit responses for getaddrinfo*/
	struct addrinfo* output;
	int err = getaddrinfo(argv[1], NULL, NULL, &output);
	if(err != 0){/*if we did not get an error here*/
		printf("Error, terminating\n");
		exit(EXIT_FAILURE);
	}
	/*two for loops going through the same elements are for formatting, arrays were being difficult*/
	printf("IP Addresses:\n");
	struct addrinfo* out;
	for(out = output; out != NULL; out = out -> ai_next){ /*getaddrinfo returns duplicates, so we look at every other entry*/
		if(out != NULL){
			out = out -> ai_next;
		}
		char name[NI_MAXHOST];
		/*NI_NUMERICHOST gives an IP address in either IPv4 or IPv6*/
		if(out != NULL){
			getnameinfo(out->ai_addr, out->ai_addrlen, name, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
		}
		else{
			break;
		}
		printf("%s\n", name);
	}
	printf("\nNames:\n");
	for(out = output; out != NULL; out = out -> ai_next){
		if(out != NULL){
                        out = out -> ai_next;
                }
                char name[NI_MAXHOST];
		/*with 0 instead of NI_NUMERICHOST we get the name*/
                if(out != NULL){
			getnameinfo(out->ai_addr, out->ai_addrlen, name, NI_MAXHOST, NULL, 0, 0);
                }
		else{
                        break;
                }  
		printf("%s\n", name);
        }
	printf("\n");
}

/*char* getIPv4(char *hostname){
	struct addrinfo* output;
	int err = getaddrinfo(hostname, NULL, NULL, &output);
	if(err != 0){//if we did not get an error here
                printf("Error, terminating\n");
                exit(EXIT_FAILURE);
        }
        //two for loops going through the same elements are for formatting, arrays were being difficult
        for(struct addrinfo* out = output; out != NULL; out = out -> ai_next -> ai_next){ //getaddrinfo returns duplicates, so we look at every other entry
                if(out->ai_addr.sin_family == AF_INET){
			char name[NI_MAXHOST];
                	//NI_NUMERICHOST gives an IP address in either IPv4 or IPv6
                	getnameinfo(out->ai_addr, out->ai_addrlen, name, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
                	return name;
		}
        }
}*/