Add some very old dns checking scripts for completeness.

check-nsservers-know

@@ -0,0 +1,29 @@
+#!/usr/bin/perl -w
+use strict;
+use warnings;
+use Net::DNS;
+
+# takes a single domain, retrieves the ns records for it and then
+# queries each server to ensure it can answer for that domain
+
+my $domain = shift;
+
+my $res   = Net::DNS::Resolver->new;
+my $query = $res->query( $domain, "NS");
+
+if ($query) {
+  foreach my $rr (grep { $_->type eq 'NS' } $query->answer) {
+    $res->nameservers( $rr->nsdname);
+
+    my $lookup = $res->query( $domain, "A");
+    if ($lookup) {
+      foreach my $record (grep { $_->type eq 'A' } $lookup->answer) {
+        print $domain, " ", $rr->nsdname, " ", $record->address, "\n";
+      }
+    } else {
+      warn "A record query for [$domain] against [", $rr->nsdname, "] failed: ", $res->errorstring, "\n";
+    }
+  }
+} else {
+  warn "NS record query for [$domain] failed : ", $res->errorstring, "\n";
+}

check-subdomains-presence

@@ -0,0 +1,24 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use Net::DNS;
+
+die "$0: please supply a subdomain to look for and one or more zones to look in\n"
+  unless @ARGV >= 2;
+
+my $domain = shift;
+my @zones  = @ARGV;
+
+my $res   = Net::DNS::Resolver->new;
+
+for my $zone ( @zones ) {
+  my $query = $res->query( "$domain.$zone", "A");
+
+  if ( $query ) {
+    foreach my $rr ( grep { $_->type eq 'A' } $query->answer ) {
+      print "Present - $domain.$zone\n";
+    }
+  } else {
+    warn "Absent - $domain.$zone - ", $res->errorstring, "\n";
+  }
+}

domain_expiry.pl

@@ -0,0 +1,25 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use Net::Domain::ExpireDate;
+
+die "$0: <file of domainnames>\n" unless @ARGV == 1;
+
+my $domainfile = shift;
+
+open( my $domains_fh, '<', $domainfile )
+  || die "Failed to open [$domainfile]: $!\n";
+
+my %domain_expiry;
+for my $domain ( sort <$domains_fh> ) {
+  my $expiration = expire_date( $domain, '%Y-%m-%d' );
+
+  $expiration ||= "unknown";
+
+  push @{ $domain_expiry{$expiration} }, $domain;
+}
+
+for my $expiry_date (sort keys %domain_expiry) {
+  print "$expiry_date -\n";
+  print "  --  $_" for  @{ $domain_expiry{$expiry_date} };
+}