#!/usr/bin/perl
###############################################################################
#
# Copyright (c) 2009  Ramon Novoa  <rnovoa@artica.es>
# Copyright (c) 2009  Artica Soluciones Tecnologicas S.L.
#
# pandora_df	Retrieve filesystem disk usage. By default information for all
#		filesystems is returned, but one or more filesystems may be
#		specified as command line parameters. If parameter start with
#		a '-', the filesystem is excluded from results.
#
# Sample usage:	./pandora_df tmpfs /dev/sda1
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.	
#
###############################################################################

use strict;

# Retrieve information from all filesystems
my $all_filesystems = 0;

# Check command line parameters
if ($#ARGV < 0) {
	$all_filesystems = 1;
}
	
# Parse command line parameters
my %filesystems;
my %excluded_filesystems;
my $onlyexclude = 1;
foreach my $fs (@ARGV) {
	if (substr($fs,0,1) eq '-') {
		$excluded_filesystems{substr($fs,1,)} = '-1%';
	} else {
		$filesystems{$fs} = '-1%';
		$onlyexclude = 0;
	}
}

if ($onlyexclude) {
	$all_filesystems = 1;
}

# Retrieve filesystem information
# -P use the POSIX output format for portability
my @df = `df -P`;
shift (@df);

# No filesystems? Something went wrong.
if ($#df < 0) {
	exit 1;
}

# Parse filesystem usage
foreach my $row (@df) {
	my @columns = split (' ', $row);
	exit 1 if ($#columns < 4);
	if (defined ($filesystems{$columns[0]}) || ($all_filesystems == 1 && !defined ($excluded_filesystems{$columns[0]}))) {
		$filesystems{$columns[0]} = $columns[4] ;
	}
}

while (my ($filesystem, $use) = each (%filesystems)) {

	# Remove the trailing %
	chop ($use);

	# Print module output
	print "<module>\n";
	print "<name><![CDATA[" . $filesystem . "]]></name>\n";
	print "<type><![CDATA[generic_data]]></type>\n";
	print "<data><![CDATA[" . $use . "]]></data>\n";
	print "<description>% of usage in this volume</description>\n";
	print "</module>\n";
}

exit 0;