#!/usr/bin/perl

my @servers = ('192.168.0.1', '192.168.0.2');
my %last;
my %first;
my $first_total;
my %cur;
my %delta;
my $oid = '1.3.6.1.4.1.2021.8.1.101.1';
my $comm = 'public';
my $first_run = 1;

while (1){

        my @time = localtime(time());
        $time[2] = '0' . $time[2] if ($time[2] < 10);
        $time[1] = '0' . $time[1] if ($time[1] < 10);
        $time[0] = '0' . $time[0] if ($time[0] < 10);
        my $output = "$time[2]:$time[1]:$time[0]";

        my $total;
        my $delta_total;
        foreach my $server (@servers){
                my $result = `snmpwalk -v1 -c $comm $server $oid`;
                chomp $result;
                $result =~ s/.* //;

                $last{$server} = $cur{$server};
                $cur{$server} = $result;

                if ($first_run){
                        $last{$server} = $result;
                        $first{$server} = $result;
                }

                $delta{$server} = $cur{$server} - $last{$server};
                my $fdelta = $cur{$server} - $first{$server};
                $fdelta = '+' . $fdelta if ($fdelta > 0);
                $output .= " $server $cur{$server}(";
                $output .= "+" if ($delta{$server} > 0);
                $output .= "$delta{$server})($fdelta)";
                $total += $cur{$server};
                $delta_total += $delta{$server};

                if ($first_run){
                        $first_total = $total;
                }
        }

        $first_run = 0;
        my $fdelta = $total - $first_total;
        $fdelta = '+' . $fdelta if ($fdelta > 0);
        $output .= " total $total(";
        $output .= '+' if ($delta_total > 0);
        $output .= "$delta_total)($fdelta)\n";

        print $output;

        sleep 15;
}