Powershell script to retry move-item until success is not working - powershell

Question

I wrote the following loop to sleep 5 seconds if the attempt to rename the file fails, however, when the event log reports failure ($? is false) it isn't retrying, it just moves on to the next block of code:
DO
{
Move-Item -Path $old_log_name -Destination $new_log_name
if($?){
Write-EventLog -LogName Application -Source my_application -EventId 4 -Message "Successfully moved $old_log_name to $new_log_name"
}
else{
Write-EventLog -LogName Application -Source my_application -EventId 4 -Message "Failed to move $old_log_name to $new_log_name : $LastExitCode sleeping 5 secconds"
Start-Sleep -Seconds 5
}
} Until ($?)
Am I missing something here??? Also on the same topic, $LastExitCode is showing up as blank. Any ideas why?

Answer 1

If I understand you correctly, what you're trying to do is the following:
Try to move the item and set a new name, the names are stored in the variables $old_log_name and $new_log_name.
If it fails to rename the item, it should write a fail message to the EventLog and stay in the loop until the item has been moved and renamed.
If it succeeds with moving and renaming the item, it should write a success message to the EventLog.
If the above is the case, you can easily achieve this by using a -not (!()) statement in correlation with the Do/Until-loop.
$old_log_name = 'C:\temp\test.txt'
$new_log_name = 'C:\temp\temp.txt'
Do {
if (!(Move-Item -Path $old_log_name -Destination $new_log_name -ErrorAction SilentlyContinue)) {
Write-EventLog -LogName Application -Source my_application -EventId 4 -Message "Failed to move $old_log_name to $new_log_name : sleeping 5 secconds"
Start-Sleep -Seconds 1
}
}
Until ((Test-Path $new_log_name) -eq $true)
Write-EventLog -LogName Application -Source my_application -EventId 4 -Message "Successfully moved $old_log_name to $new_log_name"
The above script will try to move and rename the item until the statement in the until-loop becomes $true. In other words, when the "Test-Path" returns a $true value the loop will have been completed.
The reason as to why: $LastExitCode doesn't work is because it only works with Win32 applications and not with PowerShell commands. A better solution for that in this case would be to add a $true or $false statement to a variable if the statement is $true or $false and then append an errorcode.