PowerShell: `Read-Host` should have a `-TimeoutSecond` parameter

Just to tie in a few conceptually related issues:

• https://github.com/PowerShell/PowerShell/issues/14013
• https://github.com/PowerShell/PSReadLine/issues/881
• https://github.com/PowerShell/PowerShell/issues/5434

Unfortunately the Read-Host Cmdlet does not respond to the PowerShell being stopped.

Although Microsoft.PowerShell.PSConsoleReadLine does implement a ReadLine that takes a CancellationToken it doesn’t work until a key has been entered.

#!/usr/bin/env pwsh

Import-Module PSReadLine

$runspace=[System.Management.Automation.Runspaces.Runspace]::DefaultRunspace

$cancellationTokenSource = New-Object -Type System.Threading.CancellationTokenSource
$cancellationTokenSource.CancelAfter(5000)
$cancellationToken = $cancellationTokenSource.Token
try
{
	$line = [Microsoft.PowerShell.PSConsoleReadLine]::ReadLine($runspace,$executionContext,$cancellationToken,$null)

	$line
}
finally
{
	$cancellationTokenSource.Dispose()
}

So even though the five seconds has elapsed, the ReadLine does not return until a key has been pressed.

There should also be a parameter here: -default_value_on_timeout

Or possibly you could do the same thing we did in PSES and to “cancel” ReadKey send fake input and discard it 🤷

That’s also a can of worms though. We only got away with that in PSES because of the ReadKey override hijinks we do with PSReadLine. We’d need to standardize that hack, otherwise the first bit of input after a timeout would be dropped.

hi all guys: Great, this feature is commendable. As I currently do not have this feature, I implemented it myself using a script. Well, perhaps my implementation is not perfect yet. Welcome to reference and improve. https://gitee.com/chuanjiao10/kasini3000/blob/master/read-host+timeout_v2.1.ps1