#!/usr/bin/perl
#
#
unless($ARGV[0] && $ARGV[1] && $ARGV[2]) {
        print "Please supply the following information:\n";
        print "ping-test.pl <host address> <notification sensitivity> <email address>.\n";
        exit;
}
while (1) {
        &monitor;
}
sub monitor {
use Net::Ping;
$sendmail="/usr/sbin/sendmail";
$host=$ARGV[0];
$sensitivty=$ARGV[1];
$email=$ARGV[2];
$p = Net::Ping->new("icmp", 2);
$up=$p->ping($host);
$p->close();

        if ($up) {
                print "Host $host alive.\n";
                $count{$_}=0;
        } else {
                $count{$_}++;
                print "$count{$_}\n";
                if ($count{$_} eq $sensitivty) {
                        print "Server is down - notifying admin at $email\n";
#                       open (MAIL,"|$sendmail -t -f \"$email\"");
#                       print MAIL "To: $email\n";
#                       print MAIL "From: $email\n";
#                       print MAIL "Subject: Server down\n";
                        &recheck;
                }
        }
}

sub recheck {
        if ($up) {
                $recovered{$_}++;
                if ($recovered{$_} eq $sensitivty) {
                        print "Notifying admin at $email of recovery.\n";
#                       open (MAIL,"|$sendmail -t -f \"$email\"");
#                       print MAIL "To: $email\n";
#                       print MAIL "From: $email\n";
#                       print MAIL "Subject: Server down\n";
                        $recovered{$_}=0;
                        $count{$_}=0;
        } else {
                $count{$_}++;
                print "Still trying to recover.\n";
                }
        }
}