Waiting for Process Launch

PowerShell has a built-in support to wait until a process or many processes end: simply use Wait-Process.

There is no support to do the opposite: wait until a process has started. Here is a function that can wait for any process:

#requires -Version 1
function Wait-ForProcess
{
    param
    (
        $Name = 'notepad',

        [Switch]
        $IgnoreAlreadyRunningProcesses
    )

    if ($IgnoreAlreadyRunningProcesses)
    {
        $NumberOfProcesses = (Get-Process -Name $Name -ErrorAction SilentlyContinue).Count
    }
    else
    {
        $NumberOfProcesses = 0
    }


    Write-Host "Waiting for $Name" -NoNewline
    while ( (Get-Process -Name $Name -ErrorAction SilentlyContinue).Count -eq $NumberOfProcesses )
    {
        Write-Host '.' -NoNewline
        Start-Sleep -Milliseconds 400
    }

    Write-Host ''
}

So when you run this line, PowerShell will pause until you launch a new instance of Notepad:

Wait-ForProcess -Name notepad -IgnoreAlreadyRunningProcesses

When you omit -IgnoreAlreadyRunningProcesses, then PowerShell would continue immediately if there was at least one instance of Notepad already running.

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