ares_mkquery.3

.\"
.\" Copyright 1998, 2000 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_MKQUERY 3 "20 Nov 2009"
.SH NAME
ares_mkquery \- Compose a single-question DNS query buffer
.SH SYNOPSIS
.nf
.B #include <ares.h>
.PP
.B int ares_mkquery(const char *\fIname\fP, int \fIdnsclass\fP, int \fItype\fP,
.B	unsigned short \fIid\fP, int \fIrd\fP, unsigned char **\fIbuf\fP,
.B	int *\fIbuflen\fP)
.fi
.SH DESCRIPTION
Deprecated function. See \fIares_create_query(3)\fP instead!

The
.B ares_mkquery
function composes a DNS query with a single question.
The parameter
.I name
gives the query name as a NUL-terminated C string of period-separated
labels optionally ending with a period; periods and backslashes within
a label must be escaped with a backlash.  The parameters
.I dnsclass
and
.I type
give the class and type of the query using the values defined in
.BR <arpa/nameser.h> .
The parameter
.I id
gives a 16-bit identifier for the query.  The parameter
.I rd
should be nonzero if recursion is desired, zero if not.  The query
will be placed in an allocated buffer, a pointer to which will be
stored in the variable pointed to by
.IR buf ,
and the length of which will be stored in the variable pointed to by
.IR buflen .
It is the caller's responsibility to free this buffer using
\fIares_free_string(3)\fP when it is no longer needed.

Usage of \fIares_mkquery(3)\fP is deprecated, whereas the function is
equivalent to \fIares_create_query(3)\fP with \fBmax_udp_size\fP set to
0.

.SH RETURN VALUES
.B ares_mkquery
can return any of the following values:
.TP 15
.B ARES_SUCCESS
Construction of the DNS query succeeded.
.TP 15
.B ARES_EBADNAME
The query name
.I name
could not be encoded as a domain name, either because it contained a
zero-length label or because it contained a label of more than 63
characters.
.TP 15
.B ARES_ENOMEM
Memory was exhausted.
.SH SEE ALSO
.BR ares_expand_name (3),
.BR ares_free_string (3)
.SH AUTHOR
Greg Hudson, MIT Information Systems
.br
Copyright 1998, 2000 by the Massachusetts Institute of Technology.