Интерактивная система просмотра системных руководств (man-ов)
dnsquery (1)
dnsquery (1) ( Русские man: Команды и прикладные программы пользовательского уровня )
>> dnsquery (1) ( Linux man: Команды и прикладные программы пользовательского уровня )
BSD mandoc
BSD 4
NAME
dnsquery
- query domain name servers using resolver
SYNOPSIS
dnsquery
[-n nameserver
]
[-t type
]
[-c class
]
[-r retry
]
[-p period
]
[-d
]
[-s
]
[-v
]
host
DESCRIPTION
The
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
host
and
nameserver
are treated without case-sensitivity.
OPTIONS
-n nameserver
The nameserver to be used in the query. Nameservers can appear as either
Internet addresses of the form
w.x.y.z
or can appear as domain names.
(Default: as specified in
/etc/resolv.conf . )
-t type
The type of resource record of interest. Types include:
A
address
NS
nameserver
CNAME
canonical name
PTR
domain name pointer
SOA
start of authority
WKS
well-known service
HINFO
host information
MINFO
mailbox information
MX
mail exchange
RP
responsible person
MG
mail group member
AFSDB
DCE or AFS server
ANY
wildcard
Note that any case may be used. (Default:
ANY .
-c class
The class of resource records of interest.
Classes include:
IN
Internet
HS
Hesiod
CHAOS
Chaos
ANY
wildcard
Note that any case may be used. (Default:
IN .
-r retry
The number of times to retry if the nameserver is
not responding. (Default: 4.)
-p period
Period to wait before timing out. (Default:
RES_TIMEOUT .
-d
Turn on debugging. This sets the
RES_DEBUG
bit of the resolver's
options
field. (Default: no debugging.)
-s
Use a
stream
rather than a packet. This uses a TCP stream connection with
the nameserver rather than a UDP datagram. This sets the
RES_USEVC
bit of the resolver's
options
field. (Default: UDP datagram.)
Queries of a class other than
IN
can have interesting results
since ordinarily a nameserver only has a list of root nameservers
for class
IN
resource records.
Dnsquery
uses a call to
inet_addr ();
to determine if the argument
for the
``-n
''
option is a valid Internet address. Unfortunately,
inet_addr ();
seems to cause a segmentation fault with some (bad)
IP addresses (e.g., 1.2.3.4.5).
