E-Mail alert when disk usage exceeds a configured limit.

disk_space_warning.sh

#!/bin/bash
LIMIT=95
EMAIL=root

HEAD="$(df -h | head -n1)"

df -h | tail -n+2 | while read part
do
	USED=`echo $part | awk '{ print $5 }' | cut -d'%' -f1`
	if [ $USED -gt $LIMIT ]; then
		name=$(echo $part | awk '{print $6}')
		cat | mail -s "$(hostname): low disk space warning" $EMAIL <<EOF
Partition $name reached disk usage limit (${LIMIT}%)

$HEAD
$part

EOF
	fi
done

Use column to align header and partition columns.