.\" $Id: dnsquery.1,v 8.4 2001/08/08 07:49:58 marka Exp $
.\"
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.Dd March 10, 1990
.Dt DNSQUERY @CMD_EXT_U@
.Os BSD 4
.Sh NAME
.Nm dnsquery 
.Nd query domain name servers using resolver
.Sh SYNOPSIS
.Nm dnsquery
.Op Fl n Ar nameserver
.Op Fl t Ar type
.Op Fl c Ar class
.Op Fl r Ar retry
.Op Fl p Ar period
.Op Fl d
.Op Fl s
.Op Fl v
.Ar host
.Sh DESCRIPTION
The
.Ic dnsquery
program is a general interface to nameservers via
BIND resolver library calls.  The program supports
queries to the nameserver with an opcode of QUERY.
This program is intended to be a replacement or
supplement to programs like nstest, nsquery and
nslookup.  All arguments except for
.Ar host
and
.Ar nameserver
are treated without case-sensitivity.
.Sh OPTIONS
.Bl -tag -width Fl
.It Fl n Ar nameserver
The nameserver to be used in the query.  Nameservers can appear as either 
Internet addresses of the form 
.Ar w.x.y.z 
or can appear as domain names.
(Default: as specified in 
.Pa /etc/resolv.conf . ) 
.It Fl t Ar type
The type of resource record of interest.  Types include:
.Bl -tag -width "AFSDB  " -compact -offset indent
.It Ar A
address
.It Ar NS
nameserver
.It Ar CNAME
canonical name
.It Ar PTR
domain name pointer
.It Ar SOA
start of authority
.It Ar WKS
well-known service
.It Ar HINFO
host information
.It Ar MINFO
mailbox information
.It Ar MX
mail exchange
.It Ar RP
responsible person
.It Ar MG
mail group member
.It Ar AFSDB
DCE or AFS server
.It Ar ANY
wildcard
.El
.Pp
Note that any case may be used.  (Default:  
.Ar ANY . )
.It Fl c Ar class
The class of resource records of interest.
Classes include:
.Bl -tag -width "CHAOS  " -compact -offset indent
.It Ar IN
Internet
.It Ar HS
Hesiod
.It Ar CHAOS
Chaos
.It Ar ANY
wildcard
.El
.Pp
Note that any case may be used.  (Default:  
.Ar IN . )
.It Fl r Ar retry
The number of times to retry if the nameserver is
not responding.  (Default:  4.)
.It Fl p Ar period
Period to wait before timing out.  (Default:  
.Dv RES_TIMEOUT . )
.It Fl d
Turn on debugging.  This sets the 
.Dv RES_DEBUG 
bit of the resolver's
.Ft options
field.  (Default:  no debugging.)
.It Fl s
Use a
.Em stream
rather than a packet.  This uses a TCP stream connection with
the nameserver rather than a UDP datagram.  This sets the
.Dv RES_USEVC 
bit of the resolver's
.Ft options
field.  (Default:  UDP datagram.)
.It Fl v
Synonym for the 
.Dq Fl s 
flag.
.It Ar host
The name of the host (or domain) of interest.
.El
.Sh FILES
.Bl -tag -width "<arpa/nameser.h>  " -compact
.It Pa /etc/resolv.conf 
to get the default ns and search lists
.It Pa <arpa/nameser.h>
list of usable RR types and classes
.It Pa <resolv.h>
list of resolver flags
.El
.Sh DIAGNOSTICS
If the resolver fails to answer the query and debugging has not been
turned on,
.Ic dnsquery
will simply print a message like:
.Dl Query failed (rc = 1) : Unknown host
.Pp
The value of the return code is supplied by 
.Ft h_errno .
.Sh SEE ALSO
.Xr nslookup @SYS_OPS_EXT@ , 
.Xr nstest @CMD_EXT@ , 
.Xr nsquery @CMD_EXT@ , 
.Xr named @SYS_OPS_EXT@ , 
.Xr resolver @FORMAT_EXT@ .
.Sh AUTHOR
Bryan Beecher
.Sh BUGS
Queries of a class other than 
.Ar IN 
can have interesting results
since ordinarily a nameserver only has a list of root nameservers
for class 
.Ar IN 
resource records.
.Pp
.Ic Dnsquery 
uses a call to 
.Fn inet_addr 
to determine if the argument
for the 
.Dq Fl n
option is a valid Internet address.  Unfortunately,
.Fn inet_addr 
seems to cause a segmentation fault with some (bad)
IP addresses (e.g., 1.2.3.4.5).