Mike F Robbins

Moving Parameter Validation in PowerShell to Private Functions

Mike F Robbins April 19, 2018April 18, 2018 3

While presenting one of my presentations at the PowerShell + DevOps Global Summit last week, I demonstrated why you wouldn't want to use ValidatePattern for parameter validation because of the useless error message that it returns when the input doesn't match the regular expression that's being used for validation.

function Test-ValidatePattern {
    [CmdletBinding()]
    param (
        [ValidatePattern('^(?!^(PRN|AUX|CLOCK\$|NUL|CON|COM\d|LPT\d|\..*)(\..+)?$)[^\x00-\x1f\\?*:\"";|/]+$')]
        [string]$FileName
    )
    Write-Output $FileName
}

function Test-ValidatePattern {

[CmdletBinding()]

param (

[ValidatePattern('^(?!^(PRN|AUX|CLOCK\$|NUL|CON|COM\d|LPT\d|\..*)(\..+)?$)[^\x00-\x1f\\?*:\"";|/]+$')]

[string]$FileName

)

Write-Output $FileName

}

I then demonstrated how ValidateScript could be used to build a better ValidatePattern. I have an older blog article that details this process if Read more [...]

Categories PowerShell Tags PowerShell

Remotely Uninstall ESET Antivirus with PowerShell

Mike F Robbins March 1, 2018March 1, 2018 0

Recently, one of the companies that I provide support for switched from using ESET to a new antivirus vendor. The problem is that all of their servers had both ESET File Security and the ESET Remote Administrator Agent installed which needed to be uninstalled before installing the new antivirus agent. I determined that the following commands could be used to uninstall the applications.

#Uninstall Eset Remote Administrator Agent
sc.exe delete eraagentsvc
msiexec.exe /qn /x {41F12F70-5FA9-43F5-94F4-53B54EB4EEC4}
#Uninstall Eset File Security
msiexec.exe /qn /x {22ED011A-E075-4D3D-AE41-E00F4372470A}

#Uninstall Eset Remote Administrator Agent

sc.exe delete eraagentsvc

msiexec.exe /qn /x {41F12F70-5FA9-43F5-94F4-53B54EB4EEC4}

#Uninstall Eset File Security

msiexec.exe /qn /x {22ED011A-E075-4D3D-AE41-E00F4372470A}

Running msiexec.exe /? shows the available options. Based on this information, Read more [...]

Categories PowerShell Tags PowerShell

Adding Multiple Parameter Sets to a PowerShell Function

Mike F Robbins February 22, 2018February 22, 2018 2

Sometimes you need to add more than one parameter set to a function you're creating. If that's not something you're familiar with, it can be a little confusing at first. In the following example, I want to either specify the Name or Module parameter, but not both at the same time. I also want the Path parameter to be available when using either of the parameter sets.

function Test-MrMultiParamSet {
    [CmdletBinding(DefaultParameterSetName='Name')]
    param (
        [Parameter(Mandatory,
                   ParameterSetName='Name')]
        [string[]]$Name,
        [Parameter(Mandatory,
                   ParameterSetName='Module')]
        [string[]]$Module,
        [string]$Path
    )
    $PSCmdlet.ParameterSetName
}

function Test-MrMultiParamSet {

[CmdletBinding(DefaultParameterSetName='Name')]

param (

[Parameter(Mandatory,

ParameterSetName='Name')]

[string[]]$Name,

[Parameter(Mandatory,

ParameterSetName='Module')]

[string[]]$Module,

[string]$Path

)

$PSCmdlet.ParameterSetName

}

Taking a look at the syntax shows the function shown in the previous example does indeed have two Read more [...]

Categories PowerShell Tags PowerShell

Using Plaster to create a PowerShell Script Module template

Mike F Robbins February 15, 2018February 16, 2018 0

I have a function in my MrToolkit module named New-MrScriptModule that creates the scaffolding for a new PowerShell script module. It creates a PSM1 file and a module manifest (PSD1 file) along with the folder structure for a script module. To reduce the learning curve of Plaster as much as possible, I'm simply going to replace that existing functionality with Plaster in this blog article. Then moving forward, I'll add additional functionality. For those of you who aren't familiar with Plaster, Read more [...]

Categories Plaster, PowerShell Tags Plaster, PowerShell

Temporarily Disable the Azure AD Connect Accidental Deletion Protection Feature with PowerShell

Mike F Robbins February 8, 2018February 8, 2018 1

You've implemented Azure AD Connect to synchronize accounts in your on-premises Active Directory environment to Azure AD. If you took the defaults while running the setup wizard for Azure AD Connect, then everything in your Active Directory environment is synchronized. If you decided to filter the synchronization later to only specific OU's (Organizational Units) in your Active Directory environment, you could run into a scenario where the number of deletions exceeds the default threshold of 500 Read more [...]

Categories Azure, Office 365, PowerShell Tags Azure, Office 365, PowerShell

The PowerShell Iron Scripter: My solution to prequel puzzle 3

Mike F Robbins February 3, 2018February 4, 2018 1

I've been working through the Iron Scripter 2018 prequel puzzles which can be found on PowerShell.org's website. In puzzle 3, you're asked to create a "reusable PowerShell artifact". To me, that almost always means a PowerShell function. One requirement is to pull information from the PowerShell.org RSS feed. Invoke-RestMethod which was introduced in PowerShell version 3.0 is the easiest way to accomplish that task. You're also asked to display the returned information in a way that allows the Read more [...]

Categories PowerShell, Scripting Games Tags PowerShell, Scripting Games

Help in PowerShell Core is independent of help in Windows PowerShell

Mike F Robbins January 27, 2018January 27, 2018 0

You've decided to install PowerShell Core on your Windows system. First of all, keep in mind that PowerShell Core version 6.0 is not an upgrade or replacement to Windows PowerShell version 5.1. It installs side by side on Windows systems. Being aware of this makes what is shown in this blog article make more sense, otherwise it can be confusing. Based on the response to a tweet of mine from Don Jones, it appears that I’m not the only one who thought PowerShell Core should have been version 1.0 Read more [...]

Categories PowerShell, PowerShell Core Tags PowerShell, PowerShell Core

The PowerShell Iron Scripter: My solution to prequel puzzle 2

Mike F Robbins January 26, 2018January 26, 2018 0

As I mentioned in my previous blog article, each week leading up to the PowerShell + DevOps Global Summit 2018, PowerShell.org will be posting an iron scripter prequel puzzle on their website. As their website states, think of the iron scripter as the successor to the scripting games. If you haven't done so already, I recommend reading my solution to the Iron Scripter prequel puzzle 1 because some things are glossed over in this blog article that were covered in detail in that previous one. Prequel Read more [...]

Categories PowerShell, Scripting Games Tags PowerShell

The PowerShell Iron Scripter: My solution to prequel puzzle 1

Mike F Robbins January 20, 2018January 25, 2018 0

Each week leading up to the PowerShell + DevOps Global Summit 2018, PowerShell.org will be posting an iron scripter prequel puzzle on their website. As their website states, think of the iron scripter as the successor to the scripting games. I've taken a look at the different factions and it was a difficult choice for me to choose between the Daybreak and Flawless faction. While I try to write code that's flawless, perfection is in the eye of the beholder and it's also a never-ending moving target. Read more [...]

Categories PowerShell, Scripting Games Tags PowerShell

Use PowerShell to create a bootable USB drive from a Windows 10 or Windows Server 2016 ISO

Mike F Robbins January 18, 2018January 18, 2018 6

It seems as if every time I need to reload a physical system, I'm searching the Internet to find a way to create a bootable USB drive from a Windows 10 or Windows Server 2016 ISO. I always seem to find tutorials that are using a process that's almost 20 years old. They have me using the diskpart command line utility. Diskpart which initially shipped with Windows 2000, reminds me way too much of its predecessor, the fdisk command line utility. The PowerShell commands in this blog article are written Read more [...]

Categories PowerShell Tags PowerShell

PowerShell Compare-Object doesn’t handle null values

Mike F Robbins January 8, 2018January 8, 2018 4

I thought I'd run into a bug with the Compare-Object cmdlet in PowerShell version 5.1 earlier today.

$DriveLetters = (Get-Volume).DriveLetter
$DriveLetters
Compare-Object -ReferenceObject $DriveLetters -DifferenceObject $DriveLetters

$DriveLetters = (Get-Volume).DriveLetter

$DriveLetters

Compare-Object -ReferenceObject $DriveLetters -DifferenceObject $DriveLetters

Compare-Object : Cannot bind argument to parameter 'ReferenceObject' because it is null. At line:1 char:33 + Compare-Object -ReferenceObject $DriveLetters -DifferenceObject $Driv ... + ~~~~~~~~~~~~~ + CategoryInfo : InvalidData: (:) [Compare-Object], ParameterBindingValidationException + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.CompareObjectCommand Running Read more [...]

Categories PowerShell Tags PowerShell

PowerShell 101: The No-Nonsense Beginner’s Guide to PowerShell is the featured book on Leanpub

Mike F Robbins January 5, 2018January 5, 2018 0

Learning PowerShell seems to be a hot topic for the new year. My PowerShell 101 book was the number one bestseller on Leanpub earlier this week and now it's the featured book on their website. Going to the homepage on their website, shows the book is indeed the currently featured one. I would also like to thank Tommy Maynard for the technical editing he performed on the book. If you're not following him on Twitter or reading the articles on his blog site, you should be. µ Read more [...]

Categories PowerShell Tags PowerShell

Using PowerShell to Check Remote Windows Systems for CVE-2017-5754 (Meltdown) and CVE-2017-5715 (Spectre)

Mike F Robbins January 4, 2018January 4, 2018 7

The Microsoft Security Response Center has released a PowerShell module named SpeculationControl that can be used to check for the CVE-2017-5754 (Meltdown) and CVE-2017-5715 (Spectre) vulnerabilities. The SpeculationControl module can be installed from the PowerShell Gallery with Install-Module which is part of the PowerShellGet module that ships natively with PowerShell version 5.0, but can be installed on PowerShell version 3.0 and higher.

Install-Module -Name SpeculationControl -Force

1	Install-Module -Name SpeculationControl -Force

Running Read more [...]

Categories PowerShell Tags PowerShell

Learn to write award winning PowerShell functions at SQL Saturday Nashville on January 13th

Mike F Robbins January 4, 2018January 3, 2018 0

Interested in learning how to write PowerShell functions that follow industry standard best practices? Well, you're in luck. I'll be presenting a session on "Writing award winning PowerShell functions and script modules" at SQL Saturday #698 in Nashville, Tennessee on January 13th. In addition to my session, there are a number of PowerShell sessions throughout the day so be sure to check the schedule. Here's a little about what you can expect from my presentation: "Transitioning from Read more [...]

Categories PowerShell Tags PowerShell

PowerShell 101: The No-Nonsense Beginner’s Guide to PowerShell is the number one bestseller on Leanpub

Mike F Robbins December 31, 2017December 31, 2017 1

I would like to thank everyone who helped make my new book, PowerShell 101: The No-Nonsense Beginner’s Guide to PowerShell, the number one bestseller on Leanpub.com. As shown in the previous image, PowerShell 101 is the number one top book on their homepage. It's also the number one bestseller on their site in the last week: And the book with the most copies sold in the last week: Today is the last day to purchase the book using the special year's end promotion, but as always with Read more [...]

Categories PowerShell Tags PowerShell