- memset(&sa,0,sizeof(sa));
- sa.sin_family= AF_INET;
- if (!inet_aton(arg,&sa.sin_addr)) usageerr("invalid IP address %s",arg);
+ ai_hint.ai_family = AF_UNSPEC;
+ ai_hint.ai_socktype = SOCK_DGRAM;
+ ai_hint.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV;
+
+ err = getaddrinfo(arg, 0, &ai_hint, &ai);
+ if (err) usageerr("invalid IP address %s",arg);