Powershell，检查服务是否正在运行，如果没有，请启动它

Question

I have created a powershell script that detects if X service is active or not, if not, it starts it. I also wanted to add a parameter in the while to avoid that the script gets stuck and after several attempts (2) it closes the script.

The script works, it starts the service, but it tries to do the or even though the first statement was true. And not the reason why it does not work:

$ServiceName = 'MSIREGISTER_MR'
$arrService = Get-Service -Name $ServiceName
$conteo = 0

 

while (($arrService.Status -ne 'Running') -or ($conteo -ne '2'))
{

 

    Start-Service $ServiceName
    write-host $arrService.status
    write-host 'Arrancando el servicio...'
    $conteo = $conteo +1
    Start-Sleep -seconds 5
    $arrService.Refresh()
    if ($arrService.Status -eq 'Running')
    {
        Write-Host 'El servicio esta arrancado'
    }
    else 
    {
        Write-Host 'Fallo al arrancar el servicio'
    }

 

}

Answer 1

Why this is happening

In your script today, you check for the status of the service only once, at the top of the script:

$arrService = Get-Service -Name $ServiceName

As you can see here, if I try the same using the Xbox Live Game Save Service which is currently stopped on my PC...

$service = get-service XblGameSave

Status   Name               DisplayName
------   ----               -----------
Stopped  XblGameSave        Xbox Live Game Save

C:\git\core> $service.Start()
C:\git\core> $service

Status   Name               DisplayName
------   ----               -----------
Stopped  XblGameSave        Xbox Live Game Save

I made a variable, I checked it, then I started the service.

When I check, the Xbox Live Game save service, is actually started , but my variable doesn't know about it.

However, when I refresh the variable, I can now see the new status.

PS> $service.Refresh()

Status   Name               DisplayName
------   ----               -----------
Running  XblGameSave        Xbox Live Game Save

Refreshing the variable with .Refresh() is a VERY weird thing that basically nothing else in PowerShell does other than services.

What you need to do

You need to update your code to check within the loop every time, to see if the service is now running or not.

Also, your condition on the loop seems incorrect.

while (($arrService.Status -ne 'Running') -or ($conteo -ne '2'))

This should run until the service is either running, or $conteo is greater than 2 (from your description). Here's how that should to do that in code.

while (($arrService.Status -ne 'Running') -or ($conteo -gt '2'))

Answer 2

There's a logic flaw in your conditional ; change it to:

while ($arrService.Status -ne 'Running' -and $conteo -lt 2) { ... 

That way, you exit the loop either once the service was started successfully or if $conteo reaches value 2 , ie after the 2nd unsuccessful start attempt.