$lastExitCode not working for 7-Zip update

Question

What I'm trying to do is back up some databases and part of the process is to zip them up so they're not only in one file, but a smaller file so I have the following code.

# 0 = Sunday, 1 = Monday, 2 = Tuesday, 3 = Wednesday, etc

$blocation = 'c:\SQLBackups'
$7zlocation = 'c:\Program Files\7-Zip\7z.exe'
$date = Get-Date
$daynum = [int]$date.DayOfWeek

$month = Get-Date -Format MM
$day = (Get-Date).AddDays(0).ToString('dd')
$sqlfile = "*_backup_" + $date.Year + "_" + $month + "_" + $day + "_*.bak"

cd $blocation
& $7zlocation d ABOCH2_SQL_backup.zip *.bak
& $7zlocation u ABOCH2_SQL_backup.zip *.bak
if($lastExitCode -eq 0) {
  del /q *.bak
}

After emptying out the .zip file from previous runs, update the .zip file with the newly dumped databases and then only delete the databases after the .zip was successfully updated. Issue I'm facing is that after running this the .zip file is updated with the new databases. However, the $lastExitCode is not working so the databases that were successfully added to the .zip never get deleted and I end up with a backlog of old databases accumulating.

Am I missing something, or is something wrong?

Answer 1

I am going to guess that your delete operation is actually what is failing. I would question how this is being called or that maybe you are suppressing the error. The line that has del /q *.bak when executed should have an error along the lines of:

Remove-Item : A positional parameter cannot be found that accepts argument '*.bak'.
At line:1 char:1
+ del /q *.bak
+ ~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Remove-Item], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.RemoveIt 
   emCommand

If you run the command Get-Alias del you would see that "del" is an alias for the Remove-Item cmdlet. Perhaps your $lastexitcode logic is sound? I would opt into the PowerShell way to remove those files:

Remove-Item *.csv -Confirm:$false

Or if you wanted you could use cmd

cmd.exe /c "del /q *.bak"