S>xset -display :0 dpms force off
S>

(gwmi -Class Win32_DesktopMonitor -ComputerName .)[0].InvokeMethod("SetPowerState", 6)

function Invoke-Win32([string] $dllName, [Type] $returnType, 
   [string] $methodName, [Type[]] $parameterTypes, [Object[]] $parameters)
{
   $domain = [AppDomain]::CurrentDomain
   $name = New-Object Reflection.AssemblyName 'PInvokeAssembly'
   $assembly = $domain.DefineDynamicAssembly($name, 'Run')
   $module = $assembly.DefineDynamicModule('PInvokeModule')
   $type = $module.DefineType('PInvokeType', "Public,BeforeFieldInit")

   $inputParameters = @()
   $refParameters = @()
  
   for($counter = 1; $counter -le $parameterTypes.Length; $counter++)
   {
      if($parameterTypes[$counter - 1] -eq [Ref])
      {
         $refParameters += $counter

         $parameterTypes[$counter - 1] = 
            $parameters[$counter - 1].Value.GetType().MakeByRefType()
         $inputParameters += $parameters[$counter - 1].Value
      }
      else
      {
         $inputParameters += $parameters[$counter - 1]
      }
   }

   $method = $type.DefineMethod($methodName, 'Public,HideBySig,Static,PinvokeImpl', 
      $returnType, $parameterTypes)
   foreach($refParameter in $refParameters)
   {
      $method.DefineParameter($refParameter, "Out", $null)
   }

   $ctor = [Runtime.InteropServices.DllImportAttribute].GetConstructor([string])
   $attr = New-Object Reflection.Emit.CustomAttributeBuilder $ctor, $dllName
   $method.SetCustomAttribute($attr)

   $realType = $type.CreateType()
   $realType.InvokeMember($methodName, 'Public,Static,InvokeMethod', $null, $null, 
      $inputParameters)

   foreach($refParameter in $refParameters)
   {
      $parameters[$refParameter - 1].Value = $inputParameters[$refParameter - 1]
   }
}

function SendMessage([IntPtr] $hWnd, [Int32] $message, [Int32] $wParam, [Int32] $lParam)
{
    $parameterTypes = [IntPtr], [Int32], [Int32], [Int32]
    $parameters = $hWnd, $message, $wParam, $lParam

    Invoke-Win32 "user32.dll" ([Int32]) "SendMessage" $parameterTypes $parameters
}

SendMessage ([IntPtr] 0xffff) 274 61808 2 | out-null

python -c 'import ctypes; ctypes.CDLL("libc.so.6").execl("/bin/ls", "ls", "-l", 0);'

RO>while file="$(inotifywait -q -e create --format='%w/%f' /var/crash)"
RO>do
RO>    kdialog --msgbox "Something crashed and file $file was created."
RO>done
RO>

$fsw = New-Object System.IO.FileSystemWatcher("C:\\Temp")
while ($file = $fsw.WaitForChanged("Created").Name)
{
    echo "Something temporary occured and file $file created."
}