perl下DNS模块的应用

例子如下：

#!/usr/bin/perl -w

use strict;
use Net::DNS;


# Look up a host's addresses.

my $res   = Net::DNS::Resolver->new;
my $query = $res->search("");

if ($query) {
    foreach my $rr ( grep { $rr->type eq "A" } $query->answer ) {
        print $rr->address, "\n";
    }
}
else {
    warn "query failed: ", $res->errorstring, "\n";
}


# Find the nameservers for a domain.

my $res   = Net::DNS::Resolver->new;
my $query = $res->query( "qq.com", "NS" );

if ($query) {
    foreach my $rr ( grep { $_->type eq 'NS' } $query->answer ) {
        print $rr->nsdname, "\n";
    }
}
else {
    warn "query failed: ", $res->errorstring, "\n";
}


# Find the MX records for a domain.

my $res   = Net::DNS::Resolver->new;
my $name = "qq.com";
my @mx   = mx( $res, $name );

if (@mx) {
    foreach my $rr (@mx) {
        print $rr->preference, " ", $rr->exchange, "\n";
    }
}
else {
    warn "Can't find MX records for $name: ", $res->errorstring, "\n";
}


# Print a domain's SOA record in zone file format.

my $res   = Net::DNS::Resolver->new;
my $query = $res->query( "qq.com", "SOA" );

if ($query) {
    ( $query->answer )[0]->print;
}
else {
    print "query failed: ", $res->errorstring, "\n";
}



很简单，每个注释下的内容可以独立出来使用。