main.c

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <netinet/in.h>

int main(int argc, char* argv[]){

struct addrinfo hints, *res, *p;

int status;

char ipstr[INET6_ADDRSTRLEN];

if(argc != 2){

		printf("usage: IPscanner hostname\n");
		return 1;
}


memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;

if((status = getaddrinfo(argv[1], 0, &hints, &res)) != 0){

printf("Error getaddrinfo: %s \n", gai_strerror(status));
return 2;
}

printf("IP addresses for %s \n\n", argv[1]);

for(p = res; p != NULL; p = p->ai_next){

void *addr;
char* ipver;

if(p->ai_family == AF_INET){
	struct sockaddr_in *ipv4 = (struct sockaddr_in*) p->ai_addr;
	addr = &(ipv4->sin_addr);
	ipver = "IPv4";
	}
else{
struct sockaddr_in6 *ipv6 = (struct sockaddr_in6*) p->ai_addr;
addr = &(ipv6->sin6_addr);
ipver = "IPv6";
	}
inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);
printf("%s; %s \n", ipver, ipstr);

	}
freeaddrinfo(res);
return 0;
}