lwres_getnameinfo3
Lightweight resolver socket address structure to hostname and service name
Usage
#include <lwres/netdb.h>
int lwres_getnameinfo(const struct sockaddr *sa, size_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags);
Overview
This function is equivalent to the getnameinfo(3) function defined in RFC2133. lwres_getnameinfo() returns the hostname for the struct sockaddrsa which is salen bytes long. The hostname is of length hostlen and is returned via *host. The maximum length of the hostname is 1025 bytes: NI_MAXHOST.
The name of the service associated with the port number in sa is returned in *serv. It is servlen bytes long. The maximum length of the service name is NI_MAXSERV - 32 bytes.
The flags argument sets the following bits:
NI_NOFQDN
A fully qualified domain name is not required for local hosts. The local part of the fully qualified domain name is returned instead.
NI_NUMERICHOST
Return the address in numeric form, as if calling inet_ntop(), instead of a host name.
NI_NAMEREQD
A name is required. If the hostname cannot be found in the DNS and this flag is set, a non-zero error code is returned. If the hostname is not found and the flag is not set, the address is returned in numeric form.
NI_NUMERICSERV
The service name is returned as a digit string representing the port number.
NI_DGRAM
Specifies that the service being looked up is a datagram service, and causes getservbyport() 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.
Return values
lwres_getnameinfo() returns 0 on success or a non-zero error code if an error occurs.
Releases
145 releases since Mac OS X 10.3; the text changed 10 times.