Trapping Get-WmiObject:The RPC server is unavailable.

Some assistance is required. I'm trying to find out what versions of Windows
Server we have installed on the network. I've got about everything working
except the trapping. I've tried VBScript and now PowerShell. The On Error
did not trap this error, and neither is the TRAP command.

Here is a bit of the code:

if (Ping -w $timeout $strComputer|find "Request timed out.")
{
write-host "UnPingable Computer"
}
else
{
write-host "Ping Successful"
trap { write-host "Non-Windows OS"; break }

$colItems = get-wmiobject -class "Win32_OperatingSystem" -namespace

"root\CIMV2" -computername $strComputer
foreach ($objItem in $colItems) {

$strComputerName = $objItem.CSName
$strComputerCaption = $objItem.Caption
$strComputerVersion = $objItem.CSDVersion
$strComputerDescription = $objItem.Description
}

When the code hits a non-windows server, I get:
Ping Successful
Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT:
0x80070
6BA)
At c:\scripts\Computer.ps1:27 char:29
+ $colItems = get-wmiobject <<<< -class
"Win32_OperatingSystem" -n
amespace "root\CIMV2" -computername $strComputer

I want it to fail, write "Non-Windows OS' and move on to the next computer
in the array. Any help would be appreciated.
--
TIA, Burt
===============================
There's nothing so permanent as
a temporary solution - Me.
===============================

get-wmiobject is writing an error object. I would probably use the error
variable parameter for something like this.

$obj = get-wmiobject -comp foobar win32_operatingsystem -ev myError -ea
SilentlyContinue
if ($myError -ne $null)
{
# We got an error and its stored in $myError. Do whatever you want here.
}
else
{
# Everything went as planned, $obj should have the wmi object.
}

I'm pretty sure somebody wrote a blog post explaining errors, error object,
exceptions, etc, however I can't find it right now.

- Marcel

"Burtamus" <burtamus2003@REMOVETHISyahoo.com> wrote in message
news:%23YVC9tCBHHA.4292@TK2MSFTNGP02.phx.gbl...
> Some assistance is required. I'm trying to find out what versions of
> Windows Server we have installed on the network. I've got about everything
> working except the trapping. I've tried VBScript and now PowerShell. The
> On Error did not trap this error, and neither is the TRAP command.
>
> Here is a bit of the code:
>
> if (Ping -w $timeout $strComputer|find "Request timed out.")
> {
> write-host "UnPingable Computer"
> }
> else
> {
> write-host "Ping Successful"
> trap { write-host "Non-Windows OS"; break }
>
> $colItems = get-wmiobject -class "Win32_OperatingSystem" -namespace
>
> "root\CIMV2" -computername $strComputer
> foreach ($objItem in $colItems) {
>
> $strComputerName = $objItem.CSName
> $strComputerCaption = $objItem.Caption
> $strComputerVersion = $objItem.CSDVersion
> $strComputerDescription = $objItem.Description
> }
>
> When the code hits a non-windows server, I get:
> Ping Successful
> Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT:
> 0x80070
> 6BA)
> At c:\scripts\Computer.ps1:27 char:29
> + $colItems = get-wmiobject <<<< -class
> "Win32_OperatingSystem" -n
> amespace "root\CIMV2" -computername $strComputer
>
> I want it to fail, write "Non-Windows OS' and move on to the next computer
> in the array. Any help would be appreciated.
> --
> TIA, Burt
> ===============================
> There's nothing so permanent as
> a temporary solution - Me.
> ===============================
>
>

"Marcel J. Ortiz [MSFT]" <mosoto@online.microsoft.com> wrote in message
> I'm pretty sure somebody wrote a blog post explaining errors, error
> object, exceptions, etc, however I can't find it right now.

I wonder if it is really so and I am very keen to look at it. PowerShell
documentation and help are almost (or completely?) silent.

BTW, looking at hundreds of scripts here and there I am coming into
conclusion that many people just abstain of using trap mechanism at all. Am
I wrong?

--
Thanks,
Roman

"Roman Kuzmin"

> BTW, looking at hundreds of scripts
> here and there I am coming into
> conclusion that many people just abstain
> of using trap mechanism at all. Am I wrong?
>

Been this way since scripting started.

What you are really seeing (hopefully)
are just "demo" scripts! One's that make
a quick point. Trapping just adds to the
examples - unneeded demo lines!

But then again very few use the newer
C / C++ compiler's Safe C / C++ Libraries
(in demo code either) or real production
code (based on scanning open source
code)!

Roman Kuzmin wrote:
> "Marcel J. Ortiz [MSFT]" <mosoto@online.microsoft.com> wrote in message
>> I'm pretty sure somebody wrote a blog post explaining errors, error
>> object, exceptions, etc, however I can't find it right now.
>
> I wonder if it is really so and I am very keen to look at it. PowerShell
> documentation and help are almost (or completely?) silent.
There is this:

http://blogs.msdn.com/powershell/arc...rvariable.aspx


> BTW, looking at hundreds of scripts here and there I am coming into
> conclusion that many people just abstain of using trap mechanism at all. Am
> I wrong?

I hope nobody uses it! Then Microsoft will be able to fix its broken
scoping in the next release without fear of breaking backwards
compatibility. :-)