#!/bin/bash

#    df_watcher.sh
#
#    This script will send email alerts when a provided limit has been reached
#    for partition percentage used on a host.
#
#    Meryll Larkin  20150514
#
#

# put your SMS number or email address here or a space-delimited list
emailaddr=''

# what percentage (digits only) do you want to trigger email alerts?
limit=80

emailflag=0
datestring=`date +%Y%m%d`
now=`echo $datestring | tr '\n|\r' ' '`
df -lk > /tmp/df_$now
reportmount=''

HOZTNAME=`hostname -s`
if [ "$HOZTNAME" = ''  ]
   then
   echo "Quitting, HOZTNAME not set."
   echo ""
   exit
fi
subject="$HOZTNAME Space Usage Alert"

function get_totalspace
{
    totaltotal=0
    totalused=0
    totalavail=0
    twoLineRecord=''
    lastmount='xyz'

    while read label total used available percent mount
    do
        count=$((count+1))
        if(`test "$twoLineRecord" != ''` ); then
            # This is for the case where Filesystem is on the previous line
            # So all labels are off kilter by one
            # fix that
            mount=$percent
            percent=$available
            available=$used
            used=$total
            total=$label
            label=$twoLineRecord
            twoLineRecord=''
        fi
        # change percent into a 2 digit number:
        percent=`echo $percent | sed 's/%//'`
        if( `test "$label" = "Filesystem"` ); then
            # ignore first line of df - it only contains column headers
            continue
        fi
        if( `test "$label" = "tmpfs"` ); then
            # ignore /dev/shm, /dev/vx/, tmpfs, swap
            continue
        fi
        if( `test "$mount" = "swap*"` ); then
            # ignore /dev/shm, /dev/vx/, tmpfs, swap
            continue
        fi
        if( `test "$mount" = "/dev/*"` ); then
            # ignore /dev/shm, /dev/vx/, tmpfs, swap
            continue
        elif(`test "$total" = ""` ); then
            # This is for the case where Filesystem is the only value on the line
            twoLineRecord=$label
            continue
        else
            if [ "$percent" -gt "$limit" ] ; then
                emailflag=1
                reportmount=$'\n'"$HOZTNAME:$mount is ${percent}% full"$'\n'$reportmount
            fi
        fi
    done </tmp/df_$now
}

get_totalspace

rm /tmp/df_$now

if [ "$emailflag" -eq "1" ] ; then
    echo "$reportmount" | mail -s "$subject" $emailaddr
fi

exit 0