#!/usr/bin/perl

# Pandora FMS Plugin to get memory information on Linux
# (c) 2014 Sancho Lerena <slerena@artica.es

use POSIX;

my $TOTAL=`vmstat -s | grep "total memory" | awk  '{ print $1 } '`;
my $FREE=`vmstat -s | grep "free memory" | awk  '{ print $1 } '`;
my $FREEP=($FREE/$TOTAL)*100; 
my $STOTAL=`vmstat -s | grep "total swap" | awk  '{ print $1 } '`;
my $SUSED=`vmstat -s | grep "free swap" | awk  '{ print $1 } '`;
my $SFREE=($SUSED/$STOTAL)*100;

$SFREE = floor($SFREE); 
$FREEP = floor($FREEP);

# Added 30/Dec/2014, slerena
# Available memory as FreeMemory + Cached + SwapCached.
my $freemem=`cat /proc/meminfo | grep 'MemFree' | awk '{ print \$2 } '`;
my $cached=`cat /proc/meminfo | grep '^Cached:' | awk '{ print \$2 } '`;
my $cachedswap=`cat /proc/meminfo | grep '^SwapCached:' | awk '{ print \$2 }'`;
my $available=$freemem+$cached+$cachedwap;
my $available_percent = floor(($available / $TOTAL)*100);


print "<module>\n";
print "<name>FreeMemory</name>\n";
print "<type>generic_data</type>\n";
print "<description>Free memory %. Note most linux use 99% of available memory by default, check Availablememory module for more accurate information on available physical memory on system</description>\n";
print "<unit>%</unit>\n";
print "<min_critical>0</min_critical>\n";
print "<max_critical>2</max_critical>\n";
print "<data>$FREEP</data>\n";
print "</module>\n";

print "<module>\n";
print "<name>FreeSwap</name>\n";
print "<type>generic_data</type>\n";
print "<description>Free Swap %</description>\n";
print "<unit>%</unit>\n";
print "<min_critical>0</min_critical>\n";
print "<max_critical>5</max_critical>\n";
print "<data>$SFREE</data>\n";
print "</module>\n";

print "<module>\n";
print "<name>AvailableMemory</name>\n";
print "<type>generic_data</type>\n";
print "<description>Available Physical Memory % (Free+Cached+CachedSwap)</description>\n";
print "<unit>%</unit>\n";
print "<min_critical>0</min_critical>\n";
print "<max_critical>10</max_critical>\n";
print "<data>$available_percent</data>\n";
print "</module>\n";