This post contains a few (short) useful PowerShell functions and snippets, that you can include in projects and/or your profile, and some which showcase some peculiar solutions to problems in PowerShell.
This one is for use in your profile, so you can see in Alt-Tab which Powershell console is running with which user.
I just put this as the first line in the $profile file:
$host.ui.RawUI.WindowTitle = "PowerShell - $env:USERDOMAIN\$env:USERNAME" #Alternative, but with an external executable: #$host.ui.RawUI.WindowTitle = "PowerShell - $(whoami)"
UPDATE: By combining the above line with the Is-Elevated function (shown below), formats and a condition, you can also add information indicating if the PowerShell console is running as administrator (This also shows a way to use a boolean condition to return a conditional string from an array).
Of course, the Is-Elevated function needs to be defined first, so this shows the entire construct:
function Is-Elevated {
$prp = new-object System.Security.Principal.WindowsPrincipal([System.Security.Principal.WindowsIdentity]::GetCurrent())
$prp.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)
}
$host.ui.RawUI.WindowTitle = "PowerShell - {0}\{1}{2}" -f $env:USERDOMAIN,$env:USERNAME,@(""," - as Admin")[(Is-Elevated)]
Some people consider the construction with the array ugly or unreadable.
This is how this construction then works in this example:
$host.ui.RawUI.WindowTitle = "PowerShell - {0}\{1}{2}" -f $env:USERDOMAIN,$env:USERNAME,$(if (Is-Elevated) {" - as Admin"})
This is a simple function to search the English text about_* help files in the documentation in the PowerShell install folder:
function Search-Help {
$pshelp = "$pshome\en-US\about_*.txt"
select-string -path $pshelp -pattern $args[0]
}
A shortcut to view a help article in an external window:
function Get-HelpW {
Get-Help $args[0] -showwindow
}
Investigating the methods and the properties of objects:
function Get-Methods ($obj) {
$obj | Get-Member -MemberType Method
}
function Get-Properties ($obj) {
$obj | Get-Member -MemberType Property
}
Get the static methods of the Path object:
function Get-PathMethods {
[System.IO.Path] | Get-Member -Static
}
Listing the values of all properties of an object:
function Get-PropertyValues($obj) {
$obj | Format-List *
}
Getting the full type name of the last exception, so you can use it in a Catch [] statement:
function Get-LastExceptionType() {
$Error[0].exception.GetType().fullname
}
Checking if a script process is running elevated (as Administrator):
function Is-Elevated {
$prp = new-object System.Security.Principal.WindowsPrincipal([System.Security.Principal.WindowsIdentity]::GetCurrent())
$prp.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)
}
For when you cannot remember how to call the garbage collector:
function Collect-Garbage {
[System.GC]::Collect()
}
Get a datetime value formatted as a sortable string (Defaults to current time):
function Get-QDate {
param(
[parameter()]
[DateTime]$dt = ([DateTime]::Now) # or (Get-Date)
)
"{0:yyyyMMdd-HHmmss}" -f $dt
#Alternatives:
# Get-Date $dt -format yyyyMMdd-HHmmss
# "{o:u}" -f $dt
}
Some random Date expressions:
$(Get-Date).AddDays(-16930).AddHours(-11).AddMinutes(-36) (Get-Date) - (New-TimeSpan -Day 16930 -Hour 11 -Minute 36)
Dynamically convert a hash table containing hash tables to an array of objects:
function hash2obj($data) {
$result = @();
foreach($row in $data) {
$obj = new-object PSObject
foreach($key in $row.keys) {
$obj | add-member -membertype NoteProperty -name $key -value $row[$key]
}
$result += $obj
}
return $result;
}
Excel open workbook example:
$excel = new-object -com excel.application
$wb = $excel.workbooks.open("c:\t\t.xlsx")
Windows registry modification example.
This particular code modifies an item in the registry key for Windows 10’s Update default reboot behavior, so it will not reboot if a user is still logged on (This code was tested with PS version 5.1.14393.206).
The value is not set if the registry key does not exist.
[string]$key = "HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU"
[string]$item = "NoAutoRebootWithLoggedOnUsers"
[int32]$value = 1
if (test-path $key) {
set-itemproperty $key -name $item -value $value
}
Windows Forms sample/snippet to quickly display a ListBox and two buttons (OK & Cancel) in a modal dialog-style window, and to display the selected choice afterwards:
[CmdletBinding()]
param()
# Helper function
function Get-FormControl {
param(
[parameter(Mandatory=$true)]
[object]$objControl,
[parameter(Mandatory=$true)]
[object]$objDim,
[parameter()]
[string]$sText
)
if ($objDim.x -ne $null) {
$objControl.Location = New-Object System.Drawing.Size($objDim.x, $objDim.y)
}
$objControl.Size = New-Object System.Drawing.Size($objDim.w, $objDim.h)
if ($sText -ne '' -and $sText -ne $null) {
$objControl.Text = $sText
}
return $objControl
}
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")
$oWshell = New-Object -ComObject Wscript.Shell
$winlayout = [PSCustomObject]@{
form = [PSCustomObject]@{w = 300; h = 400};
label = [PSCustomObject]@{x = 10; y = 8; w = 280; h = 15};
listbox = [PSCustomObject]@{x = 10; y = 27; w = 270; h = 315};
butOK = [PSCustomObject]@{x = 75; y = 343; w = 75; h = 23};
butCancel = [PSCustomObject]@{x = 150; y = 343; w = 75; h = 23};
}
#Create the Form
$objForm = Get-FormControl (New-Object System.Windows.Forms.Form) $winlayout.form "Window Title"
$objForm.FormBorderStyle = 'FixedDialog'; $objForm.MaximizeBox = $false
$objForm.StartPosition = "CenterScreen"
$objForm.Topmost = $True
#Add a label
$objForm.Controls.Add((Get-FormControl (New-Object System.Windows.Forms.Label) $winlayout.label "Label for the ListBox"))
#Add the buttons
$OKButton = Get-FormControl (New-Object System.Windows.Forms.Button) $winlayout.butOK "&OK"
$OKButton.DialogResult = [System.Windows.Forms.DialogResult]::OK
$objForm.Controls.Add($OKButton)
$objForm.AcceptButton = $OKButton
$CancelButton = Get-FormControl (New-Object System.Windows.Forms.Button) $winlayout.butCancel "&Cancel"
$CancelButton.DialogResult = [System.Windows.Forms.DialogResult]::Cancel
$objForm.Controls.Add($CancelButton)
$objForm.CancelButton = $CancelButton
#Add the ListBox
$objListBox = Get-FormControl (New-Object System.Windows.Forms.ListBox) $winlayout.listbox ''
$objListBox.Height = $winlayout.listbox.h #For ListBixes, Height needs to be set, next to Size
"Option 1", "Option 2", "Option 3" | foreach {
[void] $objListBox.Items.Add($_)
}
$objListBox.SelectedIndex = 0 # Leave this out if you want no option preselected
$objForm.Controls.Add($objListBox)
#$objListBox.Select() # Enable this if you want the control to be preselected
while($true) {
$result = $objForm.ShowDialog()
if ($result -eq [System.Windows.Forms.DialogResult]::CANCEL) {
break
}
if ($objListBox.SelectedIndex -ge 0) {
#$objListBox.SelectedIndex
$objListBox.SelectedItem
break
}
[void] $oWshell.Popup("Please select a valid option",0,"Popup Title",0x40)
}