Useful Powershell script to wait until solutions are deployed or retracted

After at last deciding to sort myself out with some Powershell scripts for automatically deploying or retracting solutions, I came across this one. It will wait for any scheduled jobs to complete on a WSP. I found it on Brian Cartmel's blog: http://sharepintblog.com/2011/06/13/wait-for-a-solution-to-deploy-with-powershell/

For reference, here's the script again:


## Get the solution 
$Solution = Get-SPSolution -identity $SolutionFileName
$lastStatus = ""
## loop whilst there is a Job attached to the Solution 
while ($Solution.JobExists -eq $True) 
{ 
    $currentStatus = $Solution.JobStatus 
    if ($currentStatus -ne $lastStatus) 
    { 
            Write-Host "$currentStatus…" -foreground green -nonewline 
            $lastStatus = $currentStatus 
    } 
    Write-Host "." -foreground green -nonewline 
    sleep 1 
} 
## completed 
Write-Host "" 
Write-Host "     " $Solution.LastOperationDetails -foreground green