Question

I’m trying to run a function in the background. This function needs to wait a period of time always. I’ve tried to solve the problem with start-job. But without success (the logs are empty).

My Function

Start-Job { a1 }
function a1()
{
  $timer = [diagnostics.stopwatch]::startnew()
  while ($timer.elapsed.totalseconds -lt 30) 
  {
    writelog "TESTTESTTEST" $timer.elapsed.totalseconds
    start-sleep -seconds 5
  }
  $timer.stop()
}

The log

function writelog([string]$func, [string] $Message, [string] $Value)
{
  $loggingpath = $LogPath+(Get-Date -displayhint date -Format yyyyMMdd)+".txt"
  Add-Content -Path $loggingpath -Value (" ")
  Add-Content -Path $loggingpath -Value ("Date:" + (Get-Date))
  Add-Content -Path $loggingpath -Value ("Function:" + ($func))
}

If I run the code with out start-job everything is working fine!

Answer 1

Start-Job runs the passed script block in a separate worker process. In this case that process does not have a definition of a1. You need to define both a1 and writelog either in a referenced script (file) or inline in the script block (along with any other dependencies like $LogPath).

Eg. the following does add to the file:

$j = start-job { Add-Content -Path "$env:TEMP\JobDemo.txt" -value "A message at $([datetime]::Now)" }
$j | wait-job
$j | Receive-Job
Get-Content -Path "$env:TEMP\JobDemo.txt"