A fully qualified domain name is not required for local hosts. The local part of the fully qualified domain name is returned instead.
Return the address in numeric form, as if calling inet_ntop(3), instead of a host name.
A name is required. If the host name cannot be found in DNS and this flag is set, a non-zero error code is returned. If the host name is not found and the flag is not set, the address is returned in numeric form.
The service name is returned as a digit string representing the port number.
Specifies that the service being looked up is a datagram service, and causes getservbyport(3) to be called with a second argument of "udp" instead of its default of "tcp". This is required for the few ports (512-514) that have different services for UDP and TCP.
This implementation allows numeric IPv6 address notation with scope identifier, as documented in chapter 11 of draft-ietf-ipv6-scoping-arch-02.txt. IPv6 link-local address will appear as a string like "fe80::1%ne0". Refer to getaddrinfo(3) for more information.