Powershell - Create a folder from a file name, then place that file in the folder

Question

I have a list of files say...

T123_Product_1.jpg
T123_Product_2.jpg
T123_Product_3.jpg
T456_Product_1.jpg
T456_Product_2.jpg
T456_Product_3.jpg 

etc. etc. etc. for about 900 more files

What I am needing to do is create a folder based on the characters before the first underscore, but to not repeat it since there are multiple files.

So in the example above, I would only want two folders named T123 and T456.

Then I would need the script to place the appropriate files in the folder.

I had found some codes in this thread, but they don't exactly do what I'm looking for.

https://superuser.com/questions/306890/windows-batch-script-to-create-folder-for-each-file-in-a-directory-name-it-tha

    $Files = Get-ChildItem -Path 'C:\Info\AUGUST 2011\Checklists\' -Filter 'DET1__*'
$Files | ForEach-Object {
    $FileFullName = $_.FullName
    $TempFileName = "$($FileFullName).tmp"
    $DestinationFileName = "$FileFullName\$($_.Name)"
    Move-Item $FileFullName $TempFileName
    New-Item -Path $FileFullName -ItemType Directory
    Move-Item $TempFileName $DestinationFileName
}

Any help?

Answer 1

The easiest way here would be to group the files by the first part, which will then become the directory name. In typical PowerShell pipeline manner this is fairly succinct:

Get-ChildItem -File |  # Get files
  Group-Object { $_.Name -replace '_.*' } |  # Group by part before first underscore
  ForEach-Object {
    # Create directory
    $dir = New-Item -Type Directory -Name $_.Name
    # Move files there
    $_.Group | Move-Item -Destination $dir
  }