Powershell override command - loops

Question

I'm really new to powershell (I've used javascript a bit before), and I was wondering if there's a way to have a powershell script continue running though a loop until a user inputs a specific command to override the loop and break out of it? I've been able to pause the program to wait for a response, but I need the loop to continue running until someone enters a string such as "end." For example, in the following bit of code I wanted to break the while loop and complete a specific command if the user typed "quit," "charger on," or "charger off" at any point.
$overrideProgram = "null"
$overrideProgram = Read-Host
while ($overrideProgram -ne "quit",$overrideProgram -ne "charger on",$overrideProgram -ne "charger off") {
while ($true) {
$chargeLevel = (Get-WmiObject win32_battery).estimatedChargeRemaining #defining the variable "chargeLevel" as the charge percentage
if ($chargeLevel -le 40) {chargerOn}
if ($chargeLevel -ge 80) {chargerOff}
Start-Sleep -s 30 # 30 second delay before next check
}
}
Thanks so much.

Answer 1

Best way I can think to do this is to start a background job and use a script to control the termination of that job:
$job = start-job -scriptblock {
while ($true) {
$chargeLevel = (Get-WmiObject win32_battery).estimatedChargeRemaining #defining the variable "chargeLevel" as the charge percentage
if ($chargeLevel -le 40) {chargerOff}
if ($chargeLevel -ge 80) {chargerOn}
Start-Sleep -s 30 # 30 second delay before next check
}
}
Write-Host "Background job started with id: $($job.id)"
$run = $true
while ($run) {
$op = Read-Host -Prompt "What ya wanna do?"
switch($op) {
"quit" { $run = $false }
"charger on" { $run = $false }
"charger off" { $run = $false }
default { continue }
}
}
stop-job $job.id
receive-job $job.id # If you want to see the output
remove-job $job.id
In the above, a job is started and then your script will just sit in a loop waiting for the correct input. Once it has that, it will exit the loop and proceed to stop and remove the job that was started to begin with.
You will need to extend the contents of the -scriptblock argument of Start-Job to include the chargerOn and chargerOff definitions. If the script is going to be considerably complex, probably best to save it to a file and use the -FilePath argument of Start-Job