#!/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;
eval {
$FREEP=($FREE/$TOTAL)*100; 
};
if ($@) {
	$FREEP = 0;
}
my $STOTAL=`vmstat -s | grep "total swap" | awk  '{ print $1 } '`;
my $SUSED=`vmstat -s | grep "free swap" | awk  '{ print $1 } '`;
my $SFREE;
eval {
$SFREE=($SUSED/$STOTAL)*100;
};
if ($@) {
	$SFREE = 0;
}

$SFREE = floor($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 $total_meminfo=`cat /proc/meminfo | grep 'MemTotal:' | awk '{ print \$2 }'`;
my $available=$freemem+$cached+$cachedswap;
my $available_percent = floor(($available / $total_meminfo)*100);


print "<module>\n";
print "<name><![CDATA[FreeMemory]]></name>\n";
print "<type><![CDATA[generic_data]]></type>\n";
print "<description><![CDATA[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><![CDATA[%]]></unit>\n";
print "<min_critical><![CDATA[0]]></min_critical>\n";
print "<max_critical><![CDATA[2]]></max_critical>\n";
print "<data><![CDATA[$FREEP]]></data>\n";
print "</module>\n";

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

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