How to compare substrings within a folder and an array with PowerShell? - arrays

Question

I have a folder with 100,000 files (pictures) which are named by their UPC code (8 to 14 numerical digits) followed by an underscore and other digits:
000012345678_00_1
And I have a list of 20,000 unique UPC codes in a word document (separated by commas) which should match a fifth of these pictures (I also have this list in an Excel table).
000000000000, 000000000001, 000000000011
What I'm trying to do, is to find matches between my array (the 20,000 elements list) and files in my folder so as to extract only those 20,000 pictures from the folder.
I've started by cutting the file name up to the "__" so as to get only the relevant part of the file name:
$FName = ($File -split '_')[0]
To make things harder, I also need to add a wild card " * " to the elements in the array since some extra "0" at the beginning of the files name might have been added and are not present in our array. For example, this UPC in the array "05713901" refers to this file name "00005713901_00.png "; so to find matches I will have to use the "like" operator.
Then when I've found those matches, I'll just have to use Move-Item to a new folder or subfolder.
This is what I've started to code without any result:
$Directory = "C:path_to_my_folder";
$AllFiles = Get-ChildItem $Directory
$FileNames = New-Object System.Collections.ArrayList;
foreach($File in $AllFiles)
{
$FName = ($File -split '_')[0]
$FileNames.Add($FName)
}
$Upc = Get-Content C:\path_to_my_word.docx
Compare-Object $FileNames $Upc

Answer 1

You can't read a docx-file using Get-Content, and even if it did, Compare-Object wouldn't work because your word file was a list over UPC-codes separated by a commas (a single string in powershell), while $FileNames is an array (multiple-objects).
Copy the UPC-codes from excel to notepad so you get a simple textfile with one code per line similar to this sample.
UPC.txt - Content:
000000000000
000000000001
000000000011
....
It would take a long time to run 100.000 files through a 20.000 -like test-loop each. I would create a regex-pattern that looks for either of the codes with an underscore at the end. Ex:
$Directory = "C:\path_to_my_folder";
$AllFiles = Get-ChildItem $Directory
#Generate regex that matches 00001_ or 00002_ etc. Trimming leading and trailing whitespace just to be safe.
$regex = ((Get-Content -Path "c:\UPC.txt") | ForEach-Object { "$($_.Trim())_" }) -join '|'
#Get files that match
$AllFiles | Where-Object { $_.Name -match $regex } | ForEach-Object {
#Do something, ex. Move file.
Move-Item -Path $_.FullName -Dest C:\Destination
}
Or simply
$AllFiles | Where-Object { $_.Name -match $regex } | Move-Item -Destination "C:\Destination"

Answer 2

Save your UPC codes as a plain text file. As Frode F. suggested, copying them from Excel to Notepad is probably the easiest way to do it. Save that list. Then we will load that list into PowerShell, and for each file we will split at the underscore like you did, and trim any leading zeros, then check if it is in the list of known codes. Move any files that are in the list of known UPCs with Move-Item
#Import Known UPC List
$UPCList = Get-Content C:\Path\To\UPCList.txt
#Remove Leading Zeros From List
$UPCList = $UPCList | ForEach{$_.TrimStart('0')}
$Directory = "C:path_to_my_folder"
Get-ChildItem $Directory | Where{$_.Name.Split('_')[0].TrimStart('0') -in $UPCList} | Move-Item -Dest C:\Destination