DNS 8
NAME
dns, dnsquery - domain name service
SYNOPSIS
ndb/dns [
-f " dnsfile" ] [
-h ] [
-r ] [
-x " net" ]
ndb/dnsquery [
-x " net" ] [
-s " server" ] [
"address ..." ]
DESCRIPTION
Dns is an Internet Domain Name Service (DNS) resolver.
By default it serves a file
/net/dns , that clients such as
cs (8) write and read to retrieve network data associated with domain names and Internet addresses.
The
-f option specifies the network database that contains the local DNS data (default:
/lib/ndb/local ). The
-x option specifies an alternative mount point for the network (default:
/net ). When Inferno is running hosted,
dns normally uses the host's own DNS resolver first (via
srv (2)), before searching the DNS itself; that way domain names can be
used in Inferno with minimal configuration.
The
-h option stops
dns from using the host data.
In the absence of local data, by default
dns consults the external DNS directly using some bootstrap data, but if
-r is specified and local resolvers are given in the configuration file,
dns (6), dns will query them first for all addresses, before resorting to external DNS servers.
Dnsquery queries the given
server (default:
/net/dns ) for a translation of each
address and prints the results, one per line.
If no
address is given,
dnsquery prompts for something to find in the DNS, one per line on the standard input,
of the form:
.EX
"name" " [" attribute "]"
where
name is the label of something in the DNS, and
attribute is one of its attributes from the list below:
.TF hinfox
all all data currently known locally for
name
cname
name for which
name is an alias
hinfo
host and operating system type
ip for an IP address when
name is a domain name
mx mail exchanger
ns for a list of name servers
ptr for the domain name when
name is an Internet address
soa statement-of-authority
Dnsquery queries the
server for that name/attribute combination and prints the results, one per line.
If an
attribute is not given,
dnsquery uses
ip if
name looks like a domain name,
and
ptr if it looks like an Internet address.
FILES
.TF /
lib/
ndb/
local
#sdns* service directory
/net/dns domain name service
/lib/ndb/local network database
/lib/ndb/dns DNS bootstrap data
SOURCE
/appl/cmd/ndb/dns.b
/appl/cmd/ndb/dnsquery.b
"SEE ALSO"
dns (6), cs (8) BUGS
Dns does not yet offer an external DNS server, mainly
for lack of a suitable database for local zone data.