check disk space left and send email warning

disk-space-check.sh

#!/bin/bash
ADMIN="[email protected]"
# set alert-level %
ALERT=85
MAILER=/usr/bin/mail

df -Ph | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $6 }' | while read output;
do
    usep=$(echo $output | awk '{ print $1}' | cut -d'%' -f1  )
    partition=$(echo $output | awk '{ print $2 }' )
    if [ $usep -ge $ALERT ]; then
        echo "Space low on \"$partition ($usep%)\", on server $(hostname --fqdn) at $(date)" |
            $MAILER -s "Alert: Free space low on $(hostname --fqdn):$partition" $ADMIN
    fi
done