如何根据文件名的前3个字符继续ps创建文件夹

Question

I would like a powershell script that would move files into a folder based upon the date of the file and then move into subfolders based upon the first 3 characters of the file names. I have been able to move the files to a dated folder, but do not know how to continue with powershell to create subfolders and move files to correct date subfolder. This is what I have and is working for the date:

Get-ChildItem \\servername\path\path\path\path\New_folder\*.* -Recurse |     foreach { 
$x = $_.LastWriteTime.ToShortDateString()
$new_folder_name = Get-Date $x -Format yyMMdd
$des_path = "\\servername\path\path\path\path\$new_folder_name"

if (test-path $des_path){ 
move-item $_.fullname $des_path 
} else {
new-item -ItemType directory -Path $des_path
move-item $_.fullname $des_path 
}
}

Answer 1

With the SubString() method you can extract a particular part of a given string:

$SourcePath = '\\servername\path\path\path\path\New_folder'
$DestinationRoot = '\\servername\path\path\path\path'
Get-ChildItem $SourcePath -Recurse -File |
    ForEach-Object { 
        $timeStamp = Get-Date $( $_.LastWriteTime) -Format 'yyMMdd'
        $FirstThreeLettersFromFileName = $_.BaseName.SubString(0,3)
        $destinationPath = "$DestinationRoot\$timeStamp\$FirstThreeLettersFromFileName"

        if (-not (Test-Path -Path $destinationPath)) { 
            New-Item -ItemType Directory -Path $destinationPath
        }
        Move-Item -Path $_.fullname -Destination $destinationPath 
    }