PowerShell InputBox

The other day I gave you a function to create a VBScript style message box in PowerShell. If you find yourself needing MsgBox in PowerShell, you’re likely going to want InputBox. This too is accomplished using the [microsoft.visualbasic.interaction] class. You’ll need to load the assembly first if you haven’t already.

PS C:\> [reflection.assembly]::loadwithpartialname(“microsoft.visualbasic”) | Out-Null

PS C:\> [microsoft.visualbasic.interaction]::Inputbox(“enter something”)

As in VBScript you can also specify a title and a default value. Here’s a more complete function you could call and an example.

   1: Function Show-Inputbox {
   2:  Param([string]$message=$(Throw "You must enter a prompt message"),
   3:        [string]$title="Input",
   4:        [string]$default
   5:        )
   7:  [reflection.assembly]::loadwithpartialname("microsoft.visualbasic") | Out-Null
   8:  [microsoft.visualbasic.interaction]::InputBox($message,$title,$default)
  10: }
  12: $c=Show-Inputbox -message "Enter a computername" `
  13: -title "Computername" -default $env:Computername
  15: if ($c.Trim()) {
  16:   Get-WmiObject win32_computersystem -computer $c
  17:   }

Executing the sample code will give you this inputbox:


The inputbox’s return value is whatever you enter. What you need to do, as I’ve done, is add code to validate the data.

$c=Show-Inputbox -message “Enter a computername” `
-title “Computername” -default $env:Computername

if ($c.Trim()) {
Get-WmiObject win32_computersystem -computer $c

In my example I only use the value in the Get-WMIObject expression if $c has a value. I used the Trim() method to remove any spaces. It’s possible a user could accidentally enter space somewhere so using Trim cleans that up.

Download this sample here