Example of a PowerShell loop that a user can "escape" with a keystroke

Start-InfiniteLoop.ps1

[CmdletBinding()]
param(
    [Parameter()]
    [int]$PollFrequencySeconds = 2
)

$ErrorActionPreference = "Stop"
Set-StrictMode -Version 5.0

$stopKey = "Q"
Write-Host "Press $stopKey to stop."

function userWantsToStop() {
    while ([Console]::KeyAvailable) {
        if ([Console]::ReadKey($true).Key -eq $stopKey) {
            return $true
        }
    }

    return $false
}

while (!(userWantsToStop)) {

    # Do work here

    Start-Sleep -Seconds $PollFrequencySeconds
}