Category: Powershell

Jana Sattainathan has some thoughts on when to use each of the Write- cmdlets in Powershell:

PowerShell has matured as the automation tool of choice on the Microsoft platform, be it on Windows or Azure. However, there is no official guidance on best-practices and standards around some things. At times, bloggers do things incorrectly in their examples thereby reinforcing bad practices. Hopefully, this small post will help connect some dots for you! Please comment if I am stating something that is not a generally accepted best practice. Specifically, we are going to glance at the following cmdlets

• Write-Host

• Write-Output

• Write-Debug

• Write-Warning

• Write-Error/Throw

• Write-Verbose

• Write-Progress

Write-Host is the easiest and probably most controversial of the set (because its messages are outside the pipeline), but there’s a place for each of these.

Shane O’Neill shows the trick to excluding properties in Powershell:

Hmm, Properties, ExecutionManager, and URN (hidden from view) are not needed. That is not a problem, I’ll just pipe them to Select-Object and include them in the -ExcludeProperty parameter.

It’s not quite as straightforward as you’d imagine, but Shane shows you how to do it.

Rob Sewell shows how to make one parameter’s valid set of values depend upon a previous parameter’s selected value:

But what Sander wanted was to validate the value of the second parameter depending on the value of the first one. So lets say we wanted

• If word is sun, number must be 1 or 2
• If word is moon, number must be 3 or 4
• If word is earth, number must be 5 or 6

We can use the ValidateScriptAttribute  to do this. This requires a script block which returns True or False. You can access the current parameter with $_ so we can use a script block like this

Any Powershell post with a link to June Blender is automatically 5% better in my book.

Drew Furgiuele shows how to install the SqlServer Powershell module from the Powershell Gallery:

That’s because, out of the box, Server 2012 R2  is running PowerShell 4.0. These Gallery cmdlets require PowerShell 5. To upgrade, you either need to upgrade to PowerShell 5.0 and that means installing Windows Management Framework 5.0. This is compatible with versions of Windows as far back as Windows 7, and Windows Server as far back as 2008 R2. Anything earlier, and you’re out of luck. This also requires the .NET framework 4.5 (or above). That means system updates, which could (potentially) lead to system reboots. Plan (and for the love God test) accordingly!

There’s a couple other hitches as well. One, and this sort of goes without saying, you need internet access for this to work. If your machines are behind any kind of filtering or firewall restrictions that prevent them from talking out to the internet, you’ll need to either open them up or use the Save-Module  feature to download the bits and install them yourself. Secondly, you need Administrator access for this to work. And three, if you do install them manually, you might have different versions installed for different users (or service accounts).

They’ve made it nice and easy, so read Drew’s post and give it a try.