#!/usr/bin/perl
#
# check4xfer -- check primary nameserver for modified data
#
# Written by Armin Wolfermann. Public Domain.

$primary  = "insert.your.primary.here";
$testzone = "the.zone.to.check";
$tinydata = "/var/tinydns/root/data";
$transfer = "cd /var/tinydns/root; make";
$lockfile = "/var/run/check4xfer";

die if -e $lockfile;
open(LOCK, ">$lockfile");
print LOCK $$;
close LOCK;

open(DNSQ, "/usr/local/bin/dnsq soa $testzone $primary|");
while(<DNSQ>) {
	/^answer: \S+ \d+ SOA \S+ \S+ (\d+)/ && ($modified = $1);
}
close DNSQ;

if($modified ne @{[stat($tinydata)]}[9]) { system($transfer); }

unlink $lockfile;