how to automatically update the count of background jobs running in powershell?

Question

I have few background jobs running in powershell and i'm trying to find a way to get the count of jobs "Running" and "Completed" which updates automatically once the job is completed.

function jobDetails {
    $d = Get-Job | Measure-Object -Property Name
    Write-Output "Total Number of Jobs = " $d.Count
    $d = (Get-Job -State Running)
    Write-Output "Number of Jobs Running = " $d.count
    $d = (Get-Job -State Completed)
    Write-Output "Number of Jobs Completed = " $d.count
}

please help me out as I'm a newbie to coding

Answer 1

Here you have something simple for you to experiment, there are many ways of doing it.

# How many Jobs?
$testJobs = 5

[System.Collections.ArrayList] $jobs = 1..$testJobs | ForEach-Object {
    Start-Job {
        'Hello from Job {0}' -f [runspace]::DefaultRunspace.InstanceId
        # Set a Random timer between 5 and 10 seconds
        Start-Sleep ([random]::new().Next(5, 10))
    }
}

$total = $running = $jobs.Count
$completed = 0

$results = while($jobs) {
    $id = [System.Threading.WaitHandle]::WaitAny($jobs.Finished, 200)
    if($id -ne [System.Threading.WaitHandle]::WaitTimeout) {
        $jobs[$id] | Receive-Job -Wait -AutoRemoveJob
        $jobs.RemoveAt($id)
        $running = $total - ++$completed
    }

    Clear-Host

    @(
        'Total Jobs'.PadRight(15) + ': ' + $total
        'Jobs Running'.PadRight(15) + ': ' + $running
        'Jobs Completed'.PadRight(15) + ': ' + $completed
    ) | Write-Host
}

$results | Format-Table

You could also use Write-Progress:

$total = $running = $jobs.Count
$completed = 0

$results = while($jobs) {
    $id = [System.Threading.WaitHandle]::WaitAny($jobs.Finished, 200)
    if($id -ne [System.Threading.WaitHandle]::WaitTimeout) {
        $jobs[$id] | Receive-Job -Wait -AutoRemoveJob
        $jobs.RemoveAt($id)
        $running = $total - ++$completed
    }

    $progress = @{
        Activity = 'Waiting for Jobs'
        Status   = 'Remaining Jobs {0} of {1}' -f $running, $total
        PercentComplete = $completed / $total * 100
    }
    Write-Progress @progress
}

$results | Format-Table

This answer shows a similar, more developed alternative, using a function to wait for Jobs with progress and a optional TimeOut parameter.