Manpage of LWRES_GETNAMEINFO

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# LWRES_GETNAMEINFO

Section: (3)
Updated: Jun 30, 2000
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## NAME

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_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags);

.SH "DESCRIPTION"

This function is equivalent to the getnameinfo(3) function defined in RFC2133. lwres_getnameinfo() returns the hostname for the struct sockaddr sa 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.

## 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.

## Index

NAME
SYNOPSIS
RETURN VALUES
SEE ALSO
BUGS

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Time: 08:20:01 GMT, January 07, 2003