<# Name: Check_psmsmq.ps1
    Version: 1
    Author: Tom Unsworth (mail@tomunsworth.net)
 Comment: 
    This script was disgned to monitor MSMQs through powershell and intigrated .Net.
    Feel free to update and make suggestions.
Usage

Add the below line into the NSC.ini file under the ‘[NRPE Handlers]’ header
     check_psmsmq=cmd /c echo scripts\Check_psmsmq.ps1 $ARG1$ ; exit($lastexitcode) | powershell.exe -command -

Nagios Command 
    
    $USER1$/check_nrpe  -p 5666 -t 30  -H $HOSTADDRESS$ -c check_psmsmq -a ".\\private$$\\$ARG1$ $ARG2$ $ARG3$"    
    
    $ARG1$ = Queue Name
    $ARG2$ = Warning Level
    $ARG3$ = Critical Level
    
   The minimal permissions needed for the script to monitor a queue are ‘Receive Messages, Peek Messages, Receive Journal Message, Delete Message, Delete Journal Message”   
#>   
 
Param( [String] $QueueName = $(Throw "Must specify Queuename"),
	[long] $Warn = $(Throw "Must specify warning threshold"),
	[long] $Crit = $(Throw "Must Specify Critical Threshold"))


add-type -assemblyName "System.Messaging"

$QueuesFromDotNet =  new-object System.Messaging.MessageQueue $QueueName

$Queuelength =  $QueuesFromDotNet.GetAllMessages().Length

if ($Queuelength -ge $Crit) {
    write-output "Current Messages in $($QueueName) queue : $($Queuelength) Critcal"
    write-output "|MessagesinQueue=$($Queuelength);$($Warn);$($Crit);0;100"
    ; exit(2)
   }
elseif ($Queuelength -ge $Warn) {
    write-output "Current Messages in $($QueueName) queue : $($Queuelength) Warning"
    write-output "|MessagesinQueue=$($Queuelength);$($Warn);$($Crit);0;100"
    ; exit(1)
   }
elseif ($Queuelength -lt $Warn + $Crit) {
    write-output "Current Queue Length $($Queuelength)"
    write-output "|MessagesinQueue=$($Queuelength);$($Warn);$($Crit);0;100"
    ; exit(0)
    }
else {write-output An Unkown Error occured, please check the script and try again; exit(3)}