CentOS /Fedora /RedHat /Ubuntu if disk space is low send mail

PATHS="/export/home /home"

AWK=/usr/bin/awk

DU="/usr/bin/du -ks"

GREP=/usr/bin/grep

DF="/usr/bin/df -k"

TR=/usr/bin/tr

SED=/usr/bin/sed

CAT=/usr/bin/cat

MAILFILE=/tmp/mailviews$$

MAILER=/bin/mailx

mailto="rajat@yeswedeal.com" 

for path in $PATHS

do

 DISK_AVAIL=`$DF $path |  $GREP -v "Filesystem" | $AWK '{print $5}'|$SED 's/%//g'` 

 if [ $DISK_AVAIL -gt 90 ];then

  echo "Please clean up your stuff\n\n" > $MAILFILE

  $CAT $MAILFILE | $MAILER -s "Clean up stuff" $mailto 

 fi

done