How can I allow only Y/N to be input in Read-Host without having to press Enter in Powershell?

user_2632165 0
Viewed 565

I'm trying to find a way to have something like a Read-Host to ask the user if they want to output to the file listed or not. With this I want them to either press y or n and then the code continues rather than then pressing y/n then pressing enter as well. At the moment this all works well but again it's not quite what I'm wanting.

I've tried looking into Readkey and SendKeys (to push Enter for the user) but neither work as they seem to only execute after the user has pushed Enter on the Read-Host. I'm still very new to Powershell so I'm not entirely sure whether it's actually possible or not and I've spent too much time googling/testing to find an answer that works. If I was to use Write-Host or something to do this, it needs to not show up in the log.

I've included the necessary part of my script below. It basically asks the user if the file location is correct. If it is they press y and it uses it for the output, otherwise if they push n then it loads the FolderBrowserDialog for them to select the folder they want.

I should also note this is all within a Tee-object as this code is what determines where the Tee-object output goes to.

$OutputYN = Read-Host "Do you want the output file generated to $startDirectory\FolderList.txt? (Y/N)"
If (“y”,”n” -notcontains $OutputYN) {
    Do {
    $OutputYN = Read-Host "Please input either a 'Y' for yes or a 'N' for no"
    } While (“y”,”n” -notcontains $OutputYN)
}
if ($OutputYN -eq "Y") { 
        $OutputLoc = $startDirectory
}
elseif ($OutputYN -eq "N") {
    $OutputLocDir = New-Object System.Windows.Forms.FolderBrowserDialog
    $OutputLocDir.Description = "Select a folder for the output"
    $OutputLocDir.SelectedPath = "$StartDirectory"
    if ($OutputLocDir.ShowDialog() -eq "OK") {
        $OutputLoc = $OutputLocDir.SelectedPath
        $OutputLoc = $OutputLoc.TrimEnd('\')
    }
}

EDIT:

I should have been a little more clear. I had already tried message box type stuff as well but I'd really prefer if there is a way that the user types in a y or a n. I'm not really interested in a popup box that the user has to click. If it's not possible then so be it.

powershell
4 Answers

Not sure if this is possible in the console. But when I need the user to write one answer of a specified set, I use a do-until-loop like:

Do {
    $a = Read-Host "Y / N"
} until ( 'y', 'n' - contains $a )
user_40666460

Readkey is the right way.

Use the following as template.

:prompt while ($true) {
    switch ([console]::ReadKey($true).Key) {
        { $_ -eq [System.ConsoleKey]::Y } { break prompt }
        { $_ -eq [System.ConsoleKey]::N } { return }
        default { Write-Error "Only 'Y' or 'N' allowed!" }
    }
}
write-host 'do it' -ForegroundColor Green

:prompt gives the outer loop (while) a name which can be used in the switch statement to directly break out entirely via break prompt (and not within the switch statement).

Alternative (for Windows): Use a MessageBox.

Add-Type -AssemblyName PresentationFramework

$messageBoxResult = [System.Windows.MessageBox]::Show("Do you want the output file generated to $startDirectory\FolderList.txt?" , 'Question' , [System.Windows.MessageBoxButton]::YesNo , [System.Windows.MessageBoxImage]::Question)
switch ($messageBoxResult) {
    { $_ -eq [System.Windows.MessageBoxResult]::Yes } {
        'do this'
        break
    }

    { $_ -eq [System.Windows.MessageBoxResult]::No } { 
        'do that'
        break 
    }

    default { 
        # stop
        return # or EXIT
    }
}
user_136999680

try this:

$title    = 'Question'
$question = 'Do you want the output file generated to $startDirectory\FolderList.txt?'

$choices = New-Object Collections.ObjectModel.Collection[Management.Automation.Host.ChoiceDescription]
$choices.Add((New-Object Management.Automation.Host.ChoiceDescription -ArgumentList '&Yes'))
$choices.Add((New-Object Management.Automation.Host.ChoiceDescription -ArgumentList '&No'))

$decision = $Host.UI.PromptForChoice($title, $question, $choices, 1)
if ($decision -eq 0) {
    Write-Host 'Yes'
} else {
    Write-Host 'No'
}
user_37356900

If you are on Windows, you can do it :

[System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") | Out-Null

$result = [System.Windows.Forms.MessageBox]::Show('Do you want the output file generated to $startDirectory\FolderList.txt?' , "Question" , [System.Windows.Forms.MessageBoxButtons]::YesNo, [System.Windows.Forms.MessageBoxIcon]::Question)
if ($result -eq 'Yes') {
    "Yes"
}
else
{
    "No"

}
user_37356900
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