#!/usr/bin/perl

$mailfrom = "whoever\@whatever.com";
$mailto = "whoever\@whatever.com";
$above = 90;

use FileHandle; 

@check=`df -k`;

##### Checks for lines higher than $above
foreach (@check) {
	if (m/(\d+\%)/ and $1 >=$above) {
		push @New,$_;
	}
}

##### If there is anything found, send mail 
if (@New) {
	$mail = new FileHandle; 
	$mail->open("| /usr/sbin/sendmail -t") || die "Cannot open: $!";
	$mail->print("From: $mailfrom\n");
	$mail->print("To: $mailto\n");
	$mail->print("Subject: Disk space is low!\n\n");
	$mail->print(@New, "\n");
	$mail->close();
}