#!/usr/local/bin/perl -w
use strict;
use Net::Ping;
use MIME::Lite;
unless(@ARGV) {
    print "Supply a file with hostnames \(example usage\)-- \n$0 /etc/hosts\n";
    exit;
}
my @host_array=<>;
my  $p = Net::Ping->new("icmp");
    foreach our $host (@host_array)
    {
        print "$host is ";
        &tryagain ($host) unless $p->ping($host, 5);
        print "reachable.\n";
    }
    $p->close();

sub tryagain {
print "NOT ";
sleep (60);
my ($host)=@_;
my  $p = Net::Ping->new("icmp");
    foreach our $host (@_)
    {
        &notify ($host) unless $p->ping($host, 30);
    }
    $p->close();

    }


sub notify {
my $date= localtime(time);
my ($host)=@_;
my $msg=MIME::Lite-> new(
            From    =>'ICMP Monitor <joeblow@i.com>',
            To =>'linebacker@perlmonks.org',
            Subject    =>'Ping Failure',
            Data =>"Ping failure for $host at $date"
            );
$msg->send;
    }