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.TH ARES_CREATE_QUERY 3 "17 Aug 2012"

.SH NAME

ares_create_query \- Compose a single-question DNS query buffer

.SH SYNOPSIS

.nf

#include <ares.h>

int ares_create_query(const char *\fIname\fP,

                      int \fIdnsclass\fP,

                      int \fItype\fP,

                      unsigned short \fIid\fP,

                      int \fIrd\fP,

                      unsigned char **\fIbuf\fP,

                      int *\fIbuflen\fP,

                      int \fImax_udp_size\fP)

.fi

.SH DESCRIPTION

The \fIares_create_query(3)\fP function composes a DNS query with a single

question.  The parameter \fIname\fP 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 \fIdnsclass\fP and \fItype\fP give the class and type of the

query using the values defined in \fB<arpa/nameser.h>\fP.

The parameter \fIid\fP gives a 16-bit identifier for the query.

The parameter \fIrd\fP 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 \fIbuf\fP, and the length of which will

be stored in the variable pointed to by \fIbuflen\fP.

It is the caller's responsibility to free this buffer using

\fIares_free_string(3)\fP when it is no longer needed.  The parameter

\fImax_udp_size\fP should be nonzero to activate EDNS. Usage of

\fIares_create_query(3)\fP\ with \fImax_udp_size\fP set to zero is equivalent

to using \fIares_mkquery(3)\fP.

.SH RETURN VALUES

.B ares_create_query

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 AVAILABILITY

Added in c-ares 1.10.0

.SH SEE ALSO

.BR ares_expand_name (3),

.BR ares_free_string (3),

.BR ares_mkquery (3)

.SH AUTHOR