Shell script to monitor or watch the disk space and send an email alert if the (free avilable) percentage of space is >= 90%

#!/bin/sh
# Shell script to monitor or watch the disk space
# It will send an email to $ADMIN, if the (free avilable) percentage
# of space is >= 90%
# --------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# --------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# --------------------------------------------
# Linux shell script to watch disk space (should work on other UNIX oses )
# SEE URL: http://www.cyberciti.biz/tips/shell-script-to-watch-the-disk-space.html
# set admin email so that you can get email
ADMIN="me@somewher.com"
# set alert level 90% is default
ALERT=90
df -H | grep -vE ''^Filesystem|tmpfs|cdrom'' | awk ''{ print $5 "; " $1 }'' | while read output;
do\r\n #echo $output\r\n usep=$(echo $output | awk ''{ print $1}'' | cut -d''%'' -f1  )
partition=$(echo $output | awk ''{ print $2 }'' )
if [ $usep -ge $ALERT ]; then
echo "Running out of space \\"$partition ($usep%)\\" on $(hostname) as on $(date)" |
mail -s "Alert: Almost out of disk space $usep" $ADMIN
fi
done