lwres_getnameinfo (3) Linux Manual Page
lwres_getnameinfo – lightweight resolver socket address structure to hostname and service name
Synopsis
#include <lwres/netdb.h>
- int lwres_getnameinfo(const struct sockaddr
* sa, size_tsalen, char * host, size_thostlen, char * serv, size_tservlen, int flags);
Description
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.See Also
RFC2133(), getservbyport(3), lwres(3), lwres_getnameinfo(3), lwres_getnamebyaddr(3). lwres_net_ntop(3).Bugs
RFC2133 fails to define what the nonzero return values of getnameinfo(3) are.Copyright
Copyright © 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")Copyright © 2000, 2001 Internet Software Consortium.