NAME
Net::Nslookup - Provide nslookup(1)-like capabilities
SYNOPSIS
use Net::Nslookup;
my @addrs = nslookup $host;
my @mx = nslookup(type => "MX", domain => "perl.org");
DESCRIPTION
"Net::Nslookup" provides the capabilities of the standard UNIX command
line tool nslookup(1). "Net::DNS" is a wonderful and full featured
module, but quite often, all you need is `nslookup $host`. This module
provides that functionality.
"Net::Nslookup" exports a single function, called "nslookup". "nslookup"
can be used to retrieve A, PTR, CNAME, MX, NS, SOA, TXT, and SRV
records.
my $a = nslookup(host => "use.perl.org", type => "A");
my @mx = nslookup(domain => "perl.org", type => "MX");
my @ns = nslookup(domain => "perl.org", type => "NS");
my $name = nslookup(host => "206.33.105.41", type => "PTR");
my @srv = nslookup(term => "_jabber._tcp.gmail.com", type => "SRV");
"nslookup" takes a hash of options, one of which should be *term*, and
performs a DNS lookup on that term. The type of lookup is determined by
the *type* argument. If *server* is specified (it should be an IP
address, or a reference to an array of IP addresses), that server(s)
will be used for lookups.
If only a single argument is passed in, the type defaults to *A*, that
is, a normal A record lookup.
If "nslookup" is called in a list context, and there is more than one
address, an array is returned. If "nslookup" is called in a scalar
context, and there is more than one address, "nslookup" returns the
first address. If there is only one address returned, then, naturally,
it will be the only one returned, regardless of the calling context.
*domain* and *host* are synonyms for *term*, and can be used to make
client code more readable. For example, use *domain* when getting NS
records, and use *host* for A records; both do the same thing.
*server* should be a single IP address or a reference to an array of IP
addresses:
my @a = nslookup(host => 'example.com', server => '4.2.2.1');
my @a = nslookup(host => 'example.com', server => [ '4.2.2.1', '128.103.1.1' ])
By default, when doing CNAME, MX, and NS lookups, "nslookup" returns
names, not addresses. This is a change from versions prior to 2.0, which
always tried to resolve names to addresses. Pass the *recurse => 1* flag
to "nslookup" to have it follow CNAME, MX, and NS lookups. Note that
this usage of "recurse" is not consistent with the official DNS meaning
of recurse.
# returns soemthing like ("mail.example.com")
my @mx = nslookup(domain => 'example.com', type => 'MX');
# returns soemthing like ("127.0.0.1")
my @mx = nslookup(domain => 'example.com', type => 'MX', recurse => 1);
SOA lookups return the SOA record in the same format as the `host` tool:
print nslookup(domain => 'example.com', type => 'SOA');
dns1.icann.org. hostmaster.icann.org. 2011061433 7200 3600 1209600 3600
TIMEOUTS
Lookups timeout after 15 seconds by default, but this can be configured
by passing *timeout => X* to "nslookup".
DEBUGGING
Pass *debug => 1* to "nslookup" to emit debugging messages to STDERR.
AUTHOR
darren chamberlain <
[email protected]>
