I've never tried to write a monitoring script before, but thought I would give it a go. This is what I have so far: 
#!/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 $em
+ail\n";
#                       open (MAIL,"|$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";
                }
        }
}

[download]
I know it is probably really ugly :) But basically I am trying to get it to send out a recovery email too and then start all over, but it has failed so far. It seems to work up until the call to &recheck, maybe I am going about it the wrong way. Thanks for any help

In reply to Perl question, icmp script. by eldestructo

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