Regex for dirpaths named with letters - powershell

Question

I have a large amount of folders that are named like this:
C:\Folders\A
C:\Folders\A\AB\ABC
C:\Folders\E\EA\EAB\EABA
C:\Folders\A\AZ\AZA
C:\Folders\B\BA\BAE
And in a PowerShell script I want to move some files (or create directory if it doesn't exist) to the right place. E.g FileABC.txt to C:\Folders\A\AB\ABC and FileBA.txt to C:\Folders\B\BA.
What I have now is this:
$naming just contains all the letter codes from a CSV.
if ($naming -match '^A$') {
$folderA = C:\Folders
New-Item -Name $naming -Path $folderA -Type Directory
}
Which creates C:\Folders\A. So I do the same for all the other top level folders (there are only 6 of them).
To match the 2 letter paths I do:
if ($naming -match '^A[A-Z]{1}$'){
$folderA2 = "C:\Folders\A\"
New-Item -Name $naming -Path $folderA2 -Type Directory
}
Which creates C:\Folders\A\AA, C:\Folders\A\AB etc.
The problem arises when I want to create the 3 or 4 letter directories:
I tried this:
if ($naming -match '^A[A-Z]{2}$') {
$folderA3 = 'C:\Folders\A\$($naming)\'
New-Item -Name $naming -Path $folderA3 -Type Directory
}
and:
if ($naming -match '^A[A-Z]{3}$') {
$folderA3 = 'C:\Folders\A\$($naming)\$($naming)\'
New-Item -Name $naming -Path $folderA3 -Type Directory
}
But files are not placed correctly. E.g FileABC.txt is moved to random places like C:\Folders\A\AK\ABC.
#edit
I also notice that folders are not created in the right place. Folders with 3 or 4 letter combos are placed at which seems random:
C:\Folders\E\EA\EBC
C:\Folders\A\AB\AZA
C:\Folders\E\EC\EFG\ECXA
I could do:
if ($naming -match '^AB[A-Z]{2}$')
if ($naming -match '^AC[A-Z]{2}$')
But then i would have to make one for each letter A-Z, which i feel should not be necessary.

Answer 1

Cannot totally discern the algorithm because your examples do not map to the same things, but perhaps with an approach like this, you can further refine it do to what you want. It does not use regex, but does do the mapping I believe to what you want, or close to it.
# E.g FileABC.txt to C:\Folders\A\AB\ABC and FileBA.txt to C:\Folders\B\BA.
function FileToPath($file)
{
$filePrefix = 'File'
$destPrefix = 'c:\Folders'
$fileParts = [System.IO.Path]::GetFileNameWithoutExtension($file) -split $filePrefix
$destPath = $destPrefix
$len = $fileParts[1].Length
for ($i = 0; $i -lt $len; $i++)
{
$destPath = Join-Path $destPath $fileParts[1].Substring(0,$i+1)
# or maybe the below?
#$destPath = Join-Path $destPath $fileParts[1][$i]
}
return (Join-Path $destPath $file)
}
'=== 1 ==='
$f = FileToPath 'FileABC.txt'
$f
Split-Path -Path $f -Parent
Split-Path -Path $f -Leaf
'=== 2 ==='
FileToPath 'FileBA.txt'
See also Test-Path, New-Item, Move-Item, etc.