Checking disk space using Filesys::Df with Email::Simple to email warnings.

check-df-mail.pl

#!/usr/bin/env perl

use strict;
use warnings;

use Filesys::Df;
use Email::Simple;
use Email::Sender::Simple qw(sendmail);

my $warn_limit   = 75;
my @mount_points = qw( / /tmp );
my $email_from   = 'sysadmin@example.com';
my $email_to     = 'interested@example.com';
my @messages;

for my $mount_point ( @mount_points ) {
	my $df_ref = df( $mount_point );
	my $message;
	if ($df_ref) {
		if ( $df_ref->{per} > $warn_limit ) {
			push @messages,
				"No Space on $mount_point [ $df_ref->{per}% full ]";
		}
	}
}

if (@messages) {
	my $email_body = join "\n", @messages;

	my $email = Email::Simple->create(
		header => [
			From    => $email_from,
			To      => $email_to,
			Subject => 'Disk space report',
		],
		body => $email_body,
	);

	sendmail($email);
}