#!/usr/bin/ksh
#
# SCRIPT: linux_swap_mon.ksh
#
# AUTHOR: Randy Michael
# DATE: 5/31/2007
# REV: 1.1.P
# 
# PLATFORM: Solaris Only
#
# PURPOSE: This shell script is used to produce a report of
#          the system's paging space statistics including:
#
#       Total paging space in MB, MB of Free paging space,
#       MB of Used paging space, % of paging space Used, and
#       % of paging space Free
#
# REV LIST:
#
#
# set -x # Uncomment to debug this shell script
# set -n # Uncomment to check command syntax without any execution
#
###########################################################
################ DEFINE VARIABLES HERE ####################

PC_LIMIT=65            # Upper limit of Swap space percentage
                       # before notification 
THISHOST=$(hostname)   # Host name of this machine

###########################################################
################ INITIALIZE THE REPORT ####################

echo "\nSwap Space Report for $THISHOST\n"
date

###########################################################
############# CAPTURE AND PROCESS THE DATA ################

# Use two awk statements to extract the $9 and $11 fields
# from the swap -s command output

SW_USED=$(swap -s | awk '{print $9}' | cut -dk -f1)
SW_FREE=$(swap -s | awk '{print $11}' | cut -dk -f1)

# Add SW_USED to SW_FREE to get the total swap space

((SW_TOTAL = SW_USED + SW_FREE))

# Calculate the percent used and percent free using the 
# bc utility in a here documentation with command substitution

PERCENT_USED=$(bc <<EOF
scale=4
($SW_USED / $SW_TOTAL) * 100 
EOF
) 

PERCENT_FREE=$(bc <<EOF
scale=4
($SW_FREE / $SW_TOTAL) * 100
EOF
)

# Convert the KB measurements to MB measurements

((SW_TOTAL_MB = SW_TOTAL / 1000))
((SW_USED_MB  = SW_USED / 1000))
((SW_FREE_MB  = SW_FREE / 1000))

# Produce the remaining part of the report

echo "\nTotal Amount of Swap Space:\t${SW_TOTAL_MB}MB"
echo "Total KB of Swap Space Used:\t${SW_USED_MB}MB"
echo "Total KB of Swap Space Free:\t${SW_FREE_MB}MB"
echo "\nPercent of Swap Space Used:\t${PERCENT_USED}%"
echo "\nPercent of Swap Space Free:\t${PERCENT_FREE}%"

# Grab the integer portion of the percent used

INT_PERCENT_USED=$(echo $PERCENT_USED | cut -d. -f1)

# Check to see if the percentage used maxmum threshold
# has beed exceeded

if (( PC_LIMIT <= INT_PERCENT_USED ))
then
    # Percent used has exceeded the threshold, send notification

    tput smso # Turn on reverse video!
    echo "\n\nWARNING: Swap Space has Exceeded the ${PC_LIMIT}% Upper Limit!\n"
    tput rmso # Turn off reverse video!
fi

echo "\n"