Wednesday, May 5, 2010

PowerShell DateTime to CIM_DateTime

Obviously no one that is using PowerShell is using WSMAN against a remote Linux system.  Everything assumes WMI, simple enough.

Use WSMAN against Linux and you enter into a insane land of XML and properly formatting your XML.

Take for example the simple act to send an XML string that queries a time period.

In PowerShell you type Get-Date and you get a nice, human friendly value back: Wednesday, May 05, 2010 10:24:14 AM

Now, try to send that to a CIM provider of any type (in my case a CIM provider that sits behind a WSMAN interface) and you immediately get a value invalid error.

off to Bing-land.. searching, searching, searching – absolutely nothing.  Wait, there are a couple useful things…

on MSDN the Scripting API Objects, the SWbemDateTime Object.  The what?  you say.  Isn’t it obvious? (I didn’t think so).

Here is the kicker, the CIM_DateTime format.  It expects this really strange format that looks like this:  yyyymmddHHMMSS.mmmmmmsUUU

So how do I take this:  Wednesday, May 05, 2010 10:24:14 AM and turn it into this: 20100505102415.000000-420

I have to play with objects in PowerShell, here is my script part:

$startTimeWindow = ((Get-Date) - $9Minutes)
$objScriptTime = New-Object -ComObject WbemScripting.SWbemDateTime
$startTime = $objScriptTime.Value

I first set my time window to begin 9 minutes before ‘now’.  I then create a SWbemDateTime object from the Wbem.Scripting class.  I then take the start of my time window and set this friendly formatted time to the object.  Then I retrieve the value of the object and I have a CIM_DateTime to send off to my Linux system CIM interface (through WSMAN).


vaibhav said...

I was trying to find how to convert this complicated string format to the one that powershell could recognize..n where i end up is this post :)

Hope you are doing good.


Anonymous said...

grazie mille
this info has solved my problem