#!/bin/ksh
#
# Author:  David Morris
# Version: $Id: disk-threshhold.ksh,v 1.2 2004/11/10 19:39:50 davey Exp $
# Purpose: 
# License: Released under the GNU Public Licence (GPL)
#          The terms of the GPL are available at:
#          http://www.gnu.org/licenses/gpl.html
#
# Usage:   disk-threshhold.ksh
#
# Notes:
#          This script is designed to run at user specified periods from cron.
#	   It will reset itself when ever the hour reaches $ResetHour and the 
#	   minutes are less than $ResetMinute. 
#
# Set up variables we are going to use
export Tempfile=/tmp/DiskThreshHold.tmp
export Countfile=/tmp/DiskThreshHold.cnt
export MaxCount=3
export Recipient=morrisd
export ResetHour=08
export ResetMinute=20
export TimeNow=$(/bin/date +%H:%M)
export HourNow=${TimeNow%:*}
export MinuteNow=${TimeNow#*:}
export DiskThreshHold=94
export Uname=$(/bin/uname)
export Hostname=$(/bin/hostname)
export ExcludeFromCount='^Filesystem
^mvfs
^proc
/mnt'
export GREP=/usr/xpg4/bin/grep
export AWK=/usr/bin/awk
export RM=/usr/bin/rm 
export CAT=/usr/bin/cat
export MAILX=/usr/bin/mailx
export DF=/usr/sbin/df
export TOUCH=/usr/bin/touch

case $Uname in
        AIX)    # Extract the correct fields from AIX df  
                export AwkCmd="awk '{print  \$4 \$7}'"
                 ;;
        SunOS)  # Extract the correct fields from Solaris df
                export AwkCmd="awk '{print  \$5 \$6}'"
                 ;;
        *)     echo "Operating system: $Uname not supported!"
                exit ;;
esac 

# If the $HourNow is equal to $ResetHour then remove the $Countfile
# to reset the count of mails sent

if [ $HourNow -eq $ResetHour ]
 then
  $RM $Countfile
fi

# The $Countfile keeps track of $Count to determine how many 
# times the program has run. It stops you getting hundreds of
# mail messages about the same incident. 

if [ ! -r $Countfile ];
 then
  $TOUCH $Countfile
  echo 1 > $Countfile
fi

>$Tempfile

for i in $($DF -k | $GREP -Ev "$ExcludeFromCount" | $AWK '{print $5 $6}' | $AWK -F% '{print $1 ":" $2}')
do
 LEFT=${i%:*}
 RIGHT=${i#*:}
 if [ $LEFT -gt $DiskThreshHold ]
   then
    echo "WARNING: Filesystem $RIGHT at ${LEFT}% capacity" >> $Tempfile ; 
 fi
done

$GREP "^WARNING: Filesystem" $Tempfile
Warnings=$?

Count=$($CAT $Countfile)
 
function SendResult {
 if [ $Warnings -eq 0 ]
  then
   $CAT $Tempfile | $MAILX -s "${Hostname}: Filesystem" $Recipient
   Count=$((Count+1))
   echo $Count > $Countfile
  else
   exit
 fi
}

if [ $Count -lt $MaxCount ]
 then
  SendResult
 else
  echo "Exiting because MaxCount Threshold ($MaxCount) has been reached!"
  echo "No mail will be sent to $Recipient !"
fi 

rm $Tempfile