count given domain "include" consider recursive "include"

recursive-spf.pl

#!/usr/bin/env perl 
use strict;
use warnings;

my $check_mail_domain = shift;

if ( !$check_mail_domain || $check_mail_domain =~ / / ) {
    die "1st argument is required as mail domain\n";
}

my $total_count = 0; # TODO: グローバル変数よくない

spf_include_hosts_recursive($check_mail_domain);
print "total=$total_count\n";

sub spf {
    my $host = shift;
    my $output = qx{host -t txt $host};
    return join " ", $output =~ /v=spf1 +(.*)/g;
}

sub spf_include_hosts {
    my $host = shift;
    my @hosts = spf($host) =~ /include: *(\S+)/g;
    return @hosts;
}

sub spf_include_hosts_recursive {
    my $host = shift;
    my @include_hosts = spf_include_hosts($host);
    my $count_include_hosts = scalar @include_hosts;
    $total_count += $count_include_hosts;
    printf "%s: [%d] %s\n",
        $host,
        $count_include_hosts,
        join(", ", @include_hosts);
    sleep 2;
    for my $include_host (@include_hosts) {
        spf_include_hosts_recursive($include_host);
    }
}