# ====================================================================================================
# 
# NAME: Get-WMIEvent.ps1
# 
# AUTHOR: Yan Pan
# DATE  : 10/15/2007
# 
# COMMENT: This function accepts a WQL query, a namespace and an array of property names. 
# Based on the given parameters, the function creates a watcher to 
# monitor the events retrieved by the WQL query under the namespace.
# This function allows its execution to be stopped by pressing the Esc key.
# =====================================================================================================

function Get-WMIEvent([string] $wqlQuery, [string] $namespace, [string[]] $properties)
{

$ESCkey = 27 # 27 is the key number for the Esc button. 

$objWql = New-Object System.Management.WqlEventQuery $wqlQuery

$objScope = New-Object System.Management.ManagementScope $namespace

$objWatcher = New-Object System.Management.ManagementEventWatcher $objScope, $objWql

$options = New-Object System.Management.EventWatcherOptions 
$timespan = New-Object System.TimeSpan(0, 0, 10) # Default interval is set to 10 seconds
$options.TimeOut = $timespan
$objWatcher.Options = $Options

$objWatcher.Start()

while ($true) {
        trap [System.Management.ManagementException] {continue}
        $objEvent=$objWatcher.WaitForNextEvent()
        if ($objEvent) {
                $objEvent | Select-Object $properties
                Clear-Variable -name objEvent
        }

        # Press Esc to stop the watcher and exit this function
        if ($host.ui.RawUi.KeyAvailable) { 
                $key = $host.ui.RawUI.ReadKey("NoEcho,IncludeKeyUp")
                if ($key.VirtualKeyCode -eq $ESCkey) { 
                        $objWatcher.Stop()
                        break
                }
        }
        
} 
}