Re: Mass Domain Name Lookup

[CharlesClarkson]

You're opening and closing DATAOUT too often. How about loading an array and doing the write to file just once.

sub lookup {
    my ($ldns, $fqdn) = @_;

    my ($error, $error_a);

    open DIG, "$dig \@$ldns $type $fqdn | " or die $!;
        while (<DIG>) {
            if (/;; ->>HEADER<<- opcode: QUERY\s|QUERY, status: NOERRO
+R, .*/) {
                $error = 1;
                next;
            }
            next unless /$fqdn\.\s+(\w+)(\s+A|\s+IN\sA)\s+(.*)/;

            $error_a    = 1;
            my $time    = lc($1);
            my $ip      = $3;
            my $seconds = $time =~ /[dhms]/ ? string_to_time($time) : 
+$time;
            my $extended_time = time_to_string($seconds);
            print "Request: $fqdn\tTTL: $extended_time\tIP: $ip\n" if 
+$verbose;
            push @data_out, "$ldns\t$fqdn\t$seconds\t$ip\n" if $outfil
+e;
        }
    close DIG;

    if (!$error) {
        print "Request: $fqdn\tERROR (No domain found)\n" if $verbose;
        push @data_out, "$ldns\t$fqdn\tERROR\tNO DOMAIN\n" if $outfile
+;
    } elsif (!$error_a) {
        print "Request: $fqdn\tERROR (Domain found, no A record found)
+\n" if $verbose;
        push @data_out, "$ldns\t$fqdn\tERROR\tNOT A RECORD\n" if $outf
+ile;
    }
}

As you can see, the code is tighter and easier to read. But, we now must add a test for @data_out.

if (@data_out) {
    open (DATAOUT, ">> $outfile") || die "can't open $outfile: $!";
        print DATAOUT @data_out;
    close DATAOUT;
}

This can be rewritten by taken advantage of the x operator.

foreach $thing (@ns){
    push (@provide, "Unknown");
}

push @provide, ('Unknown') x @ns;

And, finally, all those ifs in the beginning could be combined.

if (    $help
    ||  !@ns && !$nsfile
    ||  !@addr && !$addrfile
    ||  !$verbose && !$outfile ) {
    print <<END;
       .
       .
       .

HTH,
Charles K. Clarkson