Pastebin

# Check to see if the output file exists.
# If it does, it means there was a previous error
# that has not yet been cleared, so do not run.
# This prevents duplicate emails.

if [ -f fs_error.txt ] ; then
        exit
else
        #
        # Set the device for the file system you want to monitor
        # and the minimum space in MB
        fs_dev=c0d0p3
        fs_min=100

        fs_size=`df | grep $fs_dev | awk '{print $4/1024}'`
        fs_size=`echo $fs_size|awk -F \. '{print $1}'`
        echo $fs_size
        if [ $fs_size -lt $fs_min ] ; then
                touch fs_error.txt
                mail -s "Root file system low!" youremail@yourdomain.com
        fi


fi