#!/usr/bin/perl

    $now = time();
    use Time::Local;
    

    open(LEASE, "/var/lib/dhcp3/dhcpd.leases");
    foreach $line (<LEASE>) {
            chomp($line);
            $data = 1 if $line =~ /^lease /;
            $data = 0 if $line =~ /^}/;

            if ($data) {
                    if ($line =~ /^lease/) {
                            $ip = (split(" ", $line))[1];
                    } elsif ($line =~ /^  starts/) {
                            ($date, $time) = (split(" ", $line))[2,3];
                            ($y, $m, $d) = split("/", $date);
                            ($H, $M, $S) = split(":", $time);
                            $start = timelocal($S,$M,$H,$d,$m,$y);
                    } elsif ($line =~ /^  ends/) {
                            ($date, $time) = (split(" ", $line))[2,3];
                            ($y, $m, $d) = split("/", $date);
                            ($H, $M, $S) = split(":", $time);
                            $stop = timelocal($S,$M,$H,$d,$m,$y);
                    } elsif ($line =~ /^  hardware ethernet/) {
                            $mac = (split(" ", $line))[2];
                            $mac =~ s/;//;
                    } elsif ($line =~ /^  client-hostname/) {
                            $client = (split(/\"/, $line))[1];
                    }
            } else {
                    print localtime($start) . "\t" . localtime($stop) . "\t$ip\t$mac\t$client\n" if $stop >= $now;
                    $ip = ""; $start = ""; $stop = ""; $mac = ""; $client = "";
            }
    }
    close(LEASE);