#!/usr/bin/perl

use strict;

# Edit these three lines

my @filesystems = ('/','/home','/storage','/var');
my $maxpercent = '95';
my $email = 'user@domain.com';

# Don't edit below here!

my @message;
my $machinename = `uname -n`;
chomp $machinename;

my @df = `df`;

foreach my $line (@df)
{
	chomp $line;
	foreach my $fs (@filesystems)
	{
		if ($line =~ /$fs$/)
		{
			my ($percent,$foo) = split ('%',$line);
			my $percent = substr ($percent, 52, 55);
			if ($percent > $maxpercent)
			{
				my $messageline = $fs . " is at " . $percent . "%";
				@message = (@message,$messageline);
			}
		}
	}
}

# TO DEBUG UNHASH THE FOLLOWING TWO LINES.  I suggest this to test it first!

#foreach my $msgline (@message) { print "$msgline\n"; }
#exit;

if (@message) {
        open(MAIL, "|/usr/sbin/sendmail -t -oi -oem") || print "Error sending email\n";
        print MAIL "To: $email\n";
        print MAIL "From: diskspace\@$machinename\n";
        print MAIL "Subject: Low disk space warning\n\n";
	foreach my $msgline (@message) { print MAIL "$msgline\n"; }
        close(MAIL);
}