Powershell script move contents of child folder to parent, go to next folder and repeat

Kenneth Green 

Hey, Ken.

You've had a good go at it there, so let's see if we can't knock it over.

Firstly, let's quickly revisit the logical structure you've described.

- Root
--- Parent
----- Child

Looking at your first few attempts, the one thing you don't need to be doing is worrying about the -Recurse parameter since it has no meaning when moving a file, while directory moves implicitly cause nested files and directories to move - barring where a file/directory of the same name already exists in the destination beforehand.

So, what we want to do is iterate one level (i.e. not recursively) below each parent (where "parent" is a directory object, not a file object) and move that object up to the root level, and if that happens without any errors, then remove the parent directory.

You've already touched two approaches that could be taken:

1. Move; or
2. Copy and delete.

In the interested of safety and somewhat reduced coding, I've gone with the first option.

This script has basic safety built in but it's nothing profound, as I'm leveraging the way in which Move-Item is designed. Specifically, I'm referring to the behaviour described above about not moving a file or directory if it already exists in the destination.

So, the only additional safety check I've added is not removing the parent directory if any errors were thrown from the prior Move-Item command. That allows you to inspect the conflicting files and avoid data loss through unconditionally copying duplicate file(s) over the top of ones already within the destination.

Anyhow, here's the specifics.

Initial file/directory layout

Example script

$Root = "D:\Data\Temp\Forum\Root";

Get-ChildItem -Path $Root -Directory -ErrorAction:Stop |
    ForEach-Object {
        $Parent = $_.FullName;
        $Success = $true;       # Used to determine if the "parent" directory should be removed. Any exception will set this to $false, preventing removal.

        try
        {
            Get-ChildItem -Path "$Parent\*" -ErrorAction:Stop |
                ForEach-Object {
                    try
                    {
                        $_ | Move-Item -Destination $Root -ErrorAction:Stop;
                    }
                    catch
                    {
                        Write-Warning -Message "Failed to move/remove: $($_.CategoryInfo.TargetName).";
                        Write-Warning -Message ("   $($_.Exception.Message)");
                        $Success = $false;

                        # Output useable details to the pipeline so an failures can be operated on down the pipeline.
                        [PSCustomObject] @{
                            Status = "Failed";
                            Reason = $_.Exception.Message;
                            Path = $_.CategoryInfo.TargetName;
                        }
                    }
                }
        }
        catch
        {
            Write-Warning -Message "Failed to enumerate: $Parent.";
            Write-Warning -Message ("   $($_.Exception.Message)");
            $Success = $false;

                        # Output useable details to the pipeline so an failures can be operated on down the pipeline.
                        [PSCustomObject] @{
                            Status = "Failed";
                            Reason = $_.Exception.Message;
                            Path = $_.CategoryInfo.TargetName;
                        }
        }

        if ($Success)
        {
            $_ | Remove-Item -Recurse -ErrorAction:Stop;
        }
    }

Example output

And the layout contents showing the Child directories (and contents) having moved up a level - excluding the second Child1 directory which has been left in situ as per the output above:

In the output, I've written the issue to the warning channel, but I've also written a summary to the pipeline. This allows you to assign the failure results to a variable or simply pass them down another pipeline chain for further process (such as piping out to a CSV file using Export-Csv - just to list one option).

Again, it's nothing fancy but should hopefully clear up any confusion about the looping structures and when to (and not to) use the -Recursive parameter on Get-ChildItem.

Cheers,

Lain