Category: Powershell

Jess Pomfret shows us an example of creating mandatory parameters but also having a default set:

I came across a situation this week where I wanted to add the option of running an existing script,  for a specific server/database combination.  The script currently has no parameters and runs against all servers in the environment from a scheduled task.  I wanted to make sure that behavior didn’t change. The other requirement was that if I specified Server, Database should be a mandatory parameter and vice versa.
The final solution was to add the two parameters to a parameter set and make them both mandatory.  I also had to add a different DefaultParameterSet (thanks to Andrew for this idea), otherwise it defaulted to the defined parameter set, meaning the script always required both Server and Database parameters.

Click through for a demo.

Adam Bertram has a paean in honor of Tee-Object:

What does Tee-Object  do anyway? Tee-Object basically kills two birds with one stone. This cmdlet redirects output from a PowerShell command and either saves it to a file or to a variable while also returning the output to the pipeline. It allows a scripter to save the output and send the output across the pipeline all in one shot.
Let’s say a scripter wants to send some text to a file and then perform kind of task on that same text afterward. Perhaps we’re pulling a list of Windows services from a computer and saving that output to a text file to create a snapshot of the before state before we attempt to start the services. This task can be done in two separate steps or with a single one with Tee-Object .

I’ve used it several times in Powershell as well as the tee command in Linux.  It’s great when you need to do several things with the same data but don’t want to break out of your pipeline.

Chrissy LeMaire has found a technique to reduce the load time for dbatools:

I don’t know the in-depth internals of Import-Module, but I know that importing a DLL filled with C# cmdlets is extremely fast. For instance, Microsoft’s SqlServer module imports 100 commands in less than a second. Sometimes it’s closer to half a second!
I wondered if we could somehow compile our commands into a C# binary but that seemed far-fetched. One thing we could do, though, is use compression! It works for SQL Server backups, could it work for PowerShell?

Spoilers:  the answer is “yes.”  Read on to see how much faster the initial import gets.

Jeffery Hicks shares a heavy-duty Powershell prompt:

Since it is Friday and time for some more PowerShell fun, and I’ve been sharing some of my prompt functions, I thought I’d re-share my kitchen sink prompt. This PowerShell prompt function does *a lot* to things and gives you a snapshot view of your system everytime you press enter. It will work cross-platform, but because the function is using Get-CimInstance to retrieve system information it needs Windows. The prompt function will not only customize the onscreen prompt but also the title bar.

Click through for a link to the prompt as well as seeing it in action.

Chrissy LeMaire points out a bunch of changes to dbatools:

Aliases have been added for the changes, so these are not breaking changes:

• Mismatched Copy commands have been renamed to match their corresponding Get command names (ie. Copy-DbaCentralManagementServer is now Copy-DbaCmsRegServer).

• Most parameters named Password have been changed to SecurePassword. They’ve always been a SecureStringdata type but this makes that clear.

• The parameters ExcludeAllSystemDb and ExcludeAllUserDb have been changed to ExcludeSystem and ExcludeUser, respectively.

These are some of the non-breaking changes, but this latest release has several breaking changes too.  Chrissy is promising no more breaking changes for a little while, so it’s probably a good time to upgrade and check those scripts to see what you need to change.