getaddrinfo

gistfile1.c

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

char *sockname(int type) {
	if (type == SOCK_STREAM) return "SOCK_STREAM";
	if (type == SOCK_DGRAM) return "SOCK_DGRAM";
	if (type == SOCK_RAW) return "SOCK_RAW";
	return "UNKNOWN";
}

int main() {
	struct addrinfo *res;
	char addr[100];

	if (getaddrinfo("google.com", NULL, NULL, &res) == 0) {
		struct addrinfo *inf;
		
		for (inf = res; inf != NULL; inf = inf->ai_next) {
			printf("sock_type=%s\n", sockname(inf->ai_socktype));
			printf("addr=%s\n",
					inet_ntop(inf->ai_family, inf->ai_family == AF_INET ?
						(void*)&((struct sockaddr_in*)(inf->ai_addr))->sin_addr :
						(void*)&((struct sockaddr_in6*)(inf->ai_addr))->sin6_addr,
						addr, 100
					)
			);
			printf("---------------------------\n");
		}
		
		freeaddrinfo(res);
	}
	
	return 0;
}