#!/usr/bin/perl

# copyright (c) 2004,2005 Scalable Informatics LLC
# this is open source software licensed under the GPL v2.0

use constant Ndisks		=> 2;
use constant Days_per_month	=> 31;
use strict;
use POSIX qw(strftime);
use Getopt::Long;


my ($date,$fraction,$index,$rc,$dir,$link,$to);

$date		= strftime "%d",localtime;
$fraction 	= Days_per_month/Ndisks;
$index		= int(($date-1)/$fraction)+1; # make sure that the range of dates is from 0 .. Days_per_month-1
					      # to simplify extracting the integer portion.  We want to make sure
					      # that we have the index vary from 1 .. Ndisks and not 1 .. Ndisks+1
					      # so we shift the date down by one.  First day is zero ...
$dir		= "/media/usbdisk";
$link		= "/media/backup";

$rc	= GetOptions (
			"dir=s" => \$dir,
			"link=s"=> \$link
		     );

$to	= sprintf("%s%s",$dir,$index);

printf "date = %s, index = %s, link to = %s\n",$date,$index, $to;

$rc	= `/bin/rm -f $link`;
$rc	= `/bin/ln -s $to $link`;