mirror of
https://github.com/curl/curl.git
synced 2024-12-09 06:30:06 +08:00
103 lines
2.9 KiB
Groff
103 lines
2.9 KiB
Groff
.\" $Id$
|
|
.\"
|
|
.\" Copyright 1998 by the Massachusetts Institute of Technology.
|
|
.\"
|
|
.\" Permission to use, copy, modify, and distribute this
|
|
.\" software and its documentation for any purpose and without
|
|
.\" fee is hereby granted, provided that the above copyright
|
|
.\" notice appear in all copies and that both that copyright
|
|
.\" notice and this permission notice appear in supporting
|
|
.\" documentation, and that the name of M.I.T. not be used in
|
|
.\" advertising or publicity pertaining to distribution of the
|
|
.\" software without specific, written prior permission.
|
|
.\" M.I.T. makes no representations about the suitability of
|
|
.\" this software for any purpose. It is provided "as is"
|
|
.\" without express or implied warranty.
|
|
.\"
|
|
.TH ARES_GETHOSTBYADDR 3 "24 July 1998"
|
|
.SH NAME
|
|
ares_gethostbyaddr \- Initiate a host query by address
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.B #include <ares.h>
|
|
.PP
|
|
.B typedef void (*ares_host_callback)(void *\fIarg\fP, int \fIstatus\fP,
|
|
.B int \fItimeouts\fP, struct hostent *\fIhostent\fP)
|
|
.PP
|
|
.B void ares_gethostbyaddr(ares_channel \fIchannel\fP, const void *\fIaddr\fP,
|
|
.B int \fIaddrlen\fP, int \fIfamily\fP, ares_host_callback \fIcallback\fP,
|
|
.B void *\fIarg\fP)
|
|
.fi
|
|
.SH DESCRIPTION
|
|
The
|
|
.B ares_gethostbyaddr
|
|
function initiates a host query by address on the name service channel
|
|
identified by
|
|
.IR channel .
|
|
The parameters
|
|
.I addr
|
|
and
|
|
.I addrlen
|
|
give the address as a series of bytes, and
|
|
.I family
|
|
gives the type of address. When the query is complete or has failed, the ares
|
|
library will invoke \fIcallback\fP. Completion or failure of the query may
|
|
happen immediately, or may happen during a later call to
|
|
\fIares_process(3)\fP, \fIares_destroy(3)\fP or \fIares_cancel(3)\fP.
|
|
.PP
|
|
The callback argument
|
|
.I arg
|
|
is copied from the
|
|
.B ares_gethostbyaddr
|
|
argument
|
|
.IR arg .
|
|
The callback argument
|
|
.I status
|
|
indicates whether the query succeeded and, if not, how it failed. It
|
|
may have any of the following values:
|
|
.TP 19
|
|
.B ARES_SUCCESS
|
|
The host lookup completed successfully.
|
|
.TP 19
|
|
.B ARES_ENOTIMP
|
|
The ares library does not know how to look up addresses of type
|
|
.IR family .
|
|
.TP 19
|
|
.B ARES_ENOTFOUND
|
|
The address
|
|
.I addr
|
|
was not found.
|
|
.TP 19
|
|
.B ARES_ENOMEM
|
|
Memory was exhausted.
|
|
.TP 19
|
|
.B ARES_EDESTRUCTION
|
|
The name service channel
|
|
.I channel
|
|
is being destroyed; the query will not be completed.
|
|
.PP
|
|
The callback argument
|
|
.I timeouts
|
|
reports how many times a query timed out during the execution of the
|
|
given request.
|
|
.PP
|
|
On successful completion of the query, the callback argument
|
|
.I hostent
|
|
points to a
|
|
.B struct hostent
|
|
containing the name of the host returned by the query. The callback
|
|
need not and should not attempt to free the memory pointed to by
|
|
.IR hostent ;
|
|
the ares library will free it when the callback returns. If the query
|
|
did not complete successfully,
|
|
.I hostent
|
|
will be
|
|
.BR NULL .
|
|
.SH SEE ALSO
|
|
.BR ares_process (3),
|
|
.BR ares_gethostbyname (3)
|
|
.SH AUTHOR
|
|
Greg Hudson, MIT Information Systems
|
|
.br
|
|
Copyright 1998 by the Massachusetts Institute of Technology.
|