'\" te
.\" Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.
.TH DNSServiceQueryRecord 3DNS_SD "20 Aug 2007" "SunOS 5.11" "DNS Service Discovery Library Functions"
.SH NAME
DNSServiceQueryRecord \- query records from DNS
.SH SYNOPSIS
.LP
.nf
\fBcc\fR [ \fIflag\fR ... ] \fIfile\fR ... \fB-ldns_sd\fR [ \fIlibrary\fR ... ]
#include <dns_sd.h>

\fBDNSServiceErrorType\fR \fIDNSServiceQueryRecord\fR(\fBDNSServiceRef\fR *\fIsdRef\fR,
     \fBDNSServiceFlags\fR \fIflags\fR, \fBuint32_t\fR \fIinterfaceIndex\fR, \fBconst char\fR *\fIfullname\fR,
     \fBuint16_t\fR \fIrrtype\fR, \fBuint16_t\fR \fIrrclass\fR,
     \fBDNSServiceServiceQueryRecordReply\fR \fIcallBack\fR, \fBvoid\fR *\fIcontext\fR);
.fi

.LP
.nf
\fBtypedef\fR \fIvoid\fR(*\fBDNSServiceQueryRecordReply\fR)(\fBDNSServiceRef\fR \fIDNSServiceRef\fR,
     \fBDNSServiceFlags\fR \fIflags\fR, \fBuint32_t\fR \fIinterfaceIndex\fR,
     \fBDNSServiceErrorType\fR \fIerrorCode\fR, \fBconst char\fR *\fIfullname\fR,
     \fBuint16_t\fR \fIrrtype\fR, \fBuint16_t\fR \fIrrclass\fR, \fBuint16_t\fR \fIrdlen\fR,
     \fBconst void\fR *\fIrdata\fR, \fBuint32_t\fR \fIttl\fR, \fBvoid\fR *\fIcontext\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBDNSServiceQueryRecord()\fR function is used to query the daemon for any \fBDNS\fR resource record type. The \fIcallback\fR argument to \fBDNSServiceQueryRecord()\fR points to a function of type \fBDNSServiceQueryRecordReply()\fR listed above. The \fIsdRef\fR parameter in \fBDNSServiceQueryRecord()\fR points to an uninitialized \fIDNSServiceRef\fR. The \fBDNSServiceQueryRecord()\fR function returns \fBkDNSServiceErr_NoError\fR and initializes \fIsdRef\fR on success. The query runs indefinitely until the client terminates by passing the initialized \fIsdRef\fR from the query call to \fBDNSServiceRefDeallocate()\fR.
.sp
.LP
The flag \fBkDNSServiceFlagsLongLivedQuery\fR should be passed in the \fIflags\fR argument of \fBDNSServiceQueryRecord()\fR to create a "long-lived" unicast query in a non-local domain. This flag has no effect on link local multicast queries. Without this flag, unicast queries will be one-shot and only the results that are available at the time of the query will be returned. With long-lived queries, add or remove events that are available after the first call generate callbacks. The \fIinterfaceIndex\fR argument specifies the interface on which to issue the query. Most applications will pass a \fB0\fR as the \fIinterfaceIndex\fR to make the query on all interfaces. See the section "Constants for specifying an interface index" in \fB<dns_sd.h>\fR\&. The \fIfullname\fR argument indicates the full domain name of the resource record to be queried. The \fIrrtype\fR argument indicates the resource record type: \fBkDNSServiceType_PTR\fR, for example. The \fIrrclass\fR argument holds the class of the resource record to be queried (\fBkDNSServiceClass_IN\fR). The \fIcontext\fR argument can be \fINULL\fR and points to a value passed to the callback function.
.sp
.LP
The \fIsdRef\fR argument passed to the callback function is initialized by the call to \fBDNSServiceQueryRecord()\fR. Possible values for the \fIflags\fR parameter to the callback function are \fBkDNSServiceFlagsMoreComing\fR and \fBkDNSServiceFlagsAdd\fR. The \fBkDNSServiceFlagsMoreComing\fR value is set to indicate that additional results are immediately available. The \fBkDNSServiceFlagsAdd\fR value indicates that the results returned to the callback function are for a valid \fBDNS\fR record. If \fBkDNSServiceFlagsAdd\fR is not set, the results returned are for a delete event. The \fIerrorCode\fR passed to the callback is \fBkDNSServiceErr_NoError\fR on success. Otherwise, failure is indicated and other parameter values are undefined. The \fIfullname\fR parameter indicates the full domain name of the resource record . The \fIrrtype\fR indicates the resource record type. The \fIrrclass\fR indicates the class of the \fBDNS\fR resource record. The \fIrdlen\fR parameter indicates the length of the resource record \fIrdata\fR in bytes. The \fIrdata\fR parameter points to raw rdata of the resource record. The \fIttl\fR parameter indicates the time to live of the resource record in seconds. The \fIcontext\fR parameter points to the value passed  by the application in the \fBcontext\fR argument to the \fBDNSServiceQueryRecord()\fR call.
.SH RETURN VALUES
.sp
.LP
The \fBDNSServiceQueryRecord\fR function returns \fBkDNSServiceErr_NoError\fR on success. Otherwise, an error code defined in \fB<dns_sd.h>\fR is returned to indicate the specific failure that occurred.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for description of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelSafe
.TE

.SH SEE ALSO
.sp
.LP
\fBDNSServiceBrowse\fR(3DNS_SD), \fBDNSServiceRegister\fR(3DNS_SD), \fBDNSServiceResolve\fR(3DNS_SD), \fBattributes\fR(5)