Monitor DB With UNIX Shell Script

I'm looking for an inexpensive method to monitor if my Oracle database is up or down and determine if I can connect to it remotely.

Does anyone have a UNIX shell script that would allow me to attempt a SQL*Plus connect and if it fails shoot an email out to a specified distribution list?

Thanks
Ken H.

I wrote a perl script to go out and "ping" databases. If a connection to the database fails, it sends mail to a particular id (in my case, my pager).

The basics of the oracle connect are:

#!/usr/local/bin/perl -w
use strict;
use DBI;

scalar(@ARGV)==1 || die ("usage");

my $name = $ARGV[0];

my $drh = DBI->install_driver('Oracle');
my $dbh = connect($name,'/','') || die "Can not connect: $DBI::errstr\n";
$dbh->disconnect;
exit;