iOS小知识点

获取域名对应的IP地址
-(NSString *)queryIpWithDomain:(NSString *)domain
{
    struct hostent *hs;
    struct sockaddr_in server;
    if ((hs = gethostbyname([domain UTF8String])) != NULL)
    {
        server.sin_addr = *((struct in_addr*)hs->h_addr_list[0]);
        return [NSString stringWithUTF8String:inet_ntoa(server.sin_addr)];
    }
    return nil;
}