Windows Shell

Windows Shell Skill

Use PowerShell Jobs when you need to run tasks in the background, keep processes alive across multiple steps, or run several commands in parallel on Windows.
This skill is the Windows counterpart of the tmux skill (available on Linux/macOS).

Quick-start: start a background job

# Start a background job and keep a reference
$job = Start-Job -Name "myTask" -ScriptBlock {
    # Replace with the real command
    python -u my_script.py
}
Write-Host "Job started: $($job.Id) ($($job.Name))"

Check job status

# List all jobs
Get-Job

# Check a specific job
Get-Job -Name "myTask" | Select-Object Id, Name, State, HasMoreData

States: Running, Completed, Failed, Stopped.

Read output (non-destructive peek)

# Read output without consuming it (Keep = $true)
Receive-Job -Name "myTask" -Keep

Remove -Keep only when you want to consume and discard the buffered output.

Wait for completion

# Block until the job finishes (with timeout)
$job = Get-Job -Name "myTask"
$job | Wait-Job -Timeout 120   # seconds

if ($job.State -eq "Completed") {
    Receive-Job $job
} else {
    Write-Warning "Job did not finish in time. State: $($job.State)"
}

Run multiple jobs in parallel

$jobs = @(
    Start-Job -Name "task1" -ScriptBlock { python -u worker.py --id 1 },
    Start-Job -Name "task2" -ScriptBlock { python -u worker.py --id 2 },
    Start-Job -Name "task3" -ScriptBlock { python -u worker.py --id 3 }
)

# Wait for all
$jobs | Wait-Job

# Collect results
foreach ($j in $jobs) {
    Write-Host "=== $($j.Name) ==="
    Receive-Job $j
}

Start a long-running server / process

# Start server in background
$server = Start-Job -Name "devServer" -ScriptBlock {
    Set-Location $using:PWD
    python -m uvicorn app:app --reload --port 8000
}

# Poll until it is listening
for ($i = 0; $i -lt 30; $i++) {
    Start-Sleep -Seconds 1
    $out = Receive-Job $server -Keep
    if ($out -match "Application startup complete") { break }
}
Write-Host "Server ready"

Stop and clean up

# Stop a specific job
Stop-Job -Name "myTask"

# Remove it from the session
Remove-Job -Name "myTask"

# Stop and remove all jobs at once
Get-Job | Stop-Job
Get-Job | Remove-Job

Pass variables into a job

Use $using:varName to capture outer-scope variables inside -ScriptBlock:

$workDir = "C:\projects\myapp"
$port    = 9000

$job = Start-Job -Name "app" -ScriptBlock {
    Set-Location $using:workDir
    python -m http.server $using:port
}

Capture output to a file (for large logs)

Start-Job -Name "bigJob" -ScriptBlock {
    python -u long_script.py *>&1 | Tee-Object -FilePath "C:\Temp\job.log"
}

# Tail the log from the main shell
Get-Content "C:\Temp\job.log" -Wait -Tail 30

Tips

• Prefer Start-Job over Start-Process -NoNewWindow when you need to capture stdout/stderr.
• Use -Keep on Receive-Job while the job is still running so you don't lose buffered output.
• Clean up finished jobs with Remove-Job to avoid memory leaks in long sessions.
• For interactive programs that require a real TTY (e.g. full-screen TUIs), launch them directly in a new PowerShell window: Start-Process powershell -ArgumentList "-NoExit", "-Command", "your-command".
• PowerShell jobs run in a child process; the working directory defaults to the user home. Always call Set-Location $using:PWD or pass an explicit path.