#!/bin/sh

# Output warnings if disks are too full (in percentage
# terms) or have too little space available.

# This script goes through all the mounted filesystems
# and checks each to see if the disk is nearly full,
# reporting only on those disks that warrant more attention.


# Set thresholds
min_free=4000

max_in_use=55


# Get a list of all file systems.
filesystems=`df -k | grep -v Use | grep -v none | awk '{ print $6 }'`

for filesystem in $filesystems
do
    # Cache results for this file system.
    entry=`df -k $filesystem | tail -1`  

    # Split out the amount of space free as well as in-use percentage.
    free=`echo $entry | cut -d' ' -f4`
    in_use=`echo $entry | cut -d' ' -f5 | cut -d'%' -f1 `

    # Check the file system percent in use.
    if [ $(expr "$in_use > $max_in_use" ) ]
    then
        echo "$filesystem has only $free KB free at $in_use%."
    else
        # Check the available space against threshold.
        # Only make this check if the in use is OK.

        result=$( echo "
            scale=2   /* two decimal places */
            print $free < $min_free" | bc)


        #if [ $(expr "$free < $min_free" ) ]
        if [ $(expr "$result != 0" ) ]
        then
            echo "$filesystem has only $free KB free."
        fi
    fi

done