#!/usr/local/bin/perl

use warnings;
use strict;

use GDBM_File;
use Fcntl qw(O_CREAT O_RDWR);
use Mail::Mailer;

tie my %history, 'GDBM_File', "$ENV{HOME}/pinger/history", O_CREAT|O_RDWR, 0600;

my $ping=`ping -c 5 195.112.4.4|grep received`;
$ping =~ /(\d+)%/; my $packet_loss = $1;
chomp($packet_loss);

if($packet_loss != 0) { $history{time()} = $packet_loss; }

if(!defined($history{prev_state})) {
        $history{prev_state}=100;
        $history{most_recent} = time;
}

if($packet_loss == 100 && $history{prev_state} != 100) { # connection gone down
        email(
                "Connection died at ".scalar(localtime)
        );
        $history{prev_state} = $packet_loss;
        $history{most_recent} = time;
} elsif($history{prev_state} == 100) {               # previous was 100% loss
        if($packet_loss != 100) {                     # ... and we're back up
                email(
                        "Connection came back up with $packet_loss% packet\n".
                        "loss at ".scalar(localtime).".\n\n".
                        "It went down at ".
                        scalar(localtime($history{most_recent}))
                );
                $history{prev_state} = $packet_loss;
                $history{most_recent} = time;
        }
} elsif($history{prev_state} == 0) {                 # previous was 0% loss
        if($packet_loss != 0) {                       # ... now we have lossage
                email("$packet_loss% packet loss on connection at ".scalar(local
time));
                $history{prev_state} = $packet_loss;
                $history{most_recent} = time;
        }
}

sub email {
        my $body=shift;
        my $mailer=new Mail::Mailer;
        $mailer->open({
                To      => 'david@cantrell.org.uk',
                Subject => 'LINEMONITOR report from '.`hostname`
        });
        print $mailer $body;
        $mailer->close;
}

##</code><code>##

#!/usr/local/bin/perl

use warnings;
use strict;

use GDBM_File;
use Fcntl qw(O_CREAT O_RDWR);
use Data::Dumper;

tie my %history, 'GDBM_File', "$ENV{HOME}/pinger/history", O_CREAT|O_RDWR, 0600;

print "Loss%\tTime\n";
foreach my $key (sort { $a <=> $b } grep { /^\d+$/ } keys %history) {
        print "$history{$key}\t".scalar(localtime($key))."\n";
}