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Category: Powershell

Getting Started With Powershell

Published 2017-09-12 by Kevin Feasel

Rob Farley gives us a basic introduction to Powershell:

I want to take a few minutes to get you started with PowerShell, in a way that I think is less overwhelming than how I found most PowerShell material back in the day. Because you’ve told me you keep hearing about PowerShell, and that you can’t tell how to get into it.

The first thing to know is that it feels like Command Prompt on steroids, but a lot more useful than Command Prompt. You’ll see what I mean as soon as you open it. Let’s do that, but let’s open it using ‘Run as Administrator’, because that just helps for some of the demos. In real life, you’ll only open it with Admin rights if you really need to.

So click on the start button and start typing PowerShell. I don’t want you to open the ISE (yet), just find the “Windows PowerShell” shortcut, and right-click on it to choose ‘Run as Administrator’.

This T-SQL Tuesday is all about Powershell, and Rob’s is one of the first posts you should read if you’re not familiar.

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Invalid Class Error Trying To Access WMI Class

Published 2017-09-11 by Kevin Feasel

Claudio Silva troubleshoots an error which gives the user a red herring:

This can return more than one line with different ComputerManagement (like ComputerManagement10). It depends on the versions you have installed on the host. The number “10” refers to the SQL Server 2008.
Now I can uncomment the last command and run it. The result is:

Get-CimInstance : Invalid class
At line:1 char:1
+ Get-CimInstance -CimSession $CIMsession -Namespace $(“rootMicrosoftSQLServerC …
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : MetadataError: (:) [Get-CimInstance], CimException
+ FullyQualifiedErrorId : HRESULT 0x80041010,Microsoft.Management.Infrastructure.CimCmdlets.GetCimInstanceCommand
+ PSComputerName : HOST001

Ok, a different error message. Let’s dig in it. I logged in on the host and confirmed that I have a SQL Server 2008 R2 instance installed. This means that I’m not accessing a lower version than 2005 like the initial warning message was suggesting.

Read the whole thing.

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Retrieving Disk Block Size With Powershell

Published 2017-09-07 by Kevin Feasel

Naveen Kumar shows how to use Powershell to find out the block size of a particular disk in Windows:

Do you need to worry about disk block size?
I would suggest you to read below articles for getting better understanding on this topic

Disk Partition Alignment Best Practices for SQL Server
WHAT IS SQL SERVER’S IO BLOCK SIZE?

Post discussion, the next question was how do we check the disk block size for a given server?
You can do it from command line using FSutil utility. But let’s do it with PowerShell.

Read on for the code.

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Get Security Update List In Powershell

Published 2017-09-05 by Kevin Feasel

Jana Sattainathan builds a detailed CSV of Microsoft monthly security updates using Powershell:

Once I understood the data well, I realized that the raw data had to be flattened out to expand collections (like KB) at the row level into their own row so that everything has a single value in each row. Then, the grouping is easy.

It made more sense to allow grouping not just by KB but by other columns like Product or CVE. The Group-Object works fine for most cases but since there will be duplicates after the data is grouped, it makes it easier to just do it with HashTables.

Jana provides the entire solution on his site.  When reading it, I felt the urge to switch to a language which offers easier pivoting and aggregation, but the code was clear and understandable.

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The Power Of Out-GridView

Published 2017-09-04 by Kevin Feasel

Mike F. Robbins shows off Out-GridView in the context of working with Azure:

Although the Out-GridView cmdlet existed in PowerShell version 2.0, you’ll need PowerShell version 3.0 to use it as shown in this blog article. The OutputMode parameter of Out-GridView which is used in this blog article was added in PowerShell version 3.0. Also, Out-GridView can only be used on operating systems with a GUI (it cannot be used on server core).

As far as I know, there’s no way to set a default region in Azure like there is with the AWS Initialize-AWSDefaultConfiguration cmdlet. I guess if you really wanted to set a default, you could always use $PSDefaultParameterValues to set a default value for the Location parameter for the cmdlets that require it.

Out-GridView is great for what it is:  an easy UI within Powershell, with sorting and filtering built in.

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Using Visual Studio Code As A Powershell IDE

Published 2017-08-30 by Kevin Feasel

Mike Robbins has a new video up:

If you follow me on Twitter, then I’m sure you’re aware that I’ve been using nothing but VS Code (Visual Studio Code) as a replacement for the PowerShell ISE (Integrated Scripting Environment) for the past couple of weeks and while I had tried it in the past, I didn’t previously think it was ready for prime time. That’s now changed with all of the updates and work that has gone into it. From what I’ve found, it works fairly well flawlessly so I’ve created a short and simple video to help others get VS Code installed and configured as a replacement for the PowerShell ISE.

Click through for some interesting comments, especially one from Mike Fal.

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Handling Sensitive Data With Powershell

Published 2017-08-23 by Kevin Feasel

Adam Bertram shows off the data protection API in Powershell:

We need to automatically read this information without our intervention. This is where you sometimes see people get lazy and add passwords in plain text into the script. That’s a big no-no, and there’s a better way.

 PowerShell has native support for something called the data protection API (DPAPI). DPAPI is a built-in way Windows users can use certificates to encrypt and decrypt information on the fly which is perfect for PowerShell scripting. No username and password required. We simply need a certificate installed which can be self-signed.

This is about much more than storing and decoding passwords, so check it out.

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Powershell: Text Search In A Table Value

Published 2017-08-21 by Kevin Feasel

Shane O’Neill clarifies a misunderstanding in Powershell:

and you are running the following PowerShell command to check if the results contain a value…

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$String = "abc"
$Array = @(Invoke-Sqlcmd -ServerInstance "SQLServer" -Database "Database" -Query "SELECT code FROM dbo.users")
$Array.Contains($string)

It will return FALSE.

Now we know that the FALSE is false because we know that the string is in there!
This code is proven to work with arrays as stated here by the “Hey, Scripting Guy!”s so this was getting filed under “WTF PowerShell”

It’s a good post, so check it out and remember that DataRows aren’t strings.

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Basic Powershell Regex

Published 2017-08-15 by Kevin Feasel

Adam Bertram shows how to use regular expressions for pattern matching in Powershell:

However, regex has traditionally been a topic that most IT pros shy away from when they first see how it works. Admittedly, regex does take a bit of getting used to, and you’re still probably going to have to do some Googling every time you need to use it. But learning how PowerShell integrates regex into its language is a skill that’s much easier learned and one that will come in handy often.

First of all, when someone says “working with regex,” that can mean a lot of things so let’s break it down a little bit. Regex is a method of string matching. Its sole purpose is to match and parse strings from within other strings. This can mean a lot of things and PowerShell allows you to do just about anything here, particularly as it has the full power of the .NET Framework. For our purposes, let’s investigate a few ways PowerShell allows you to match strings and how to parse strings with regex and PowerShell.

Read on for a couple sample scenarios.

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