Powershell - Assigning unique file names to duplicated files using list inside a .csv or .txt - powershell

Question

I have limited experience with Powershell doing very basic tasks by itself (such as simple renaming or moving files), but I've never created one that has the need to actually extract information from inside a file and apply that data directly to a file name.
I'd like to create a script that can reference a simple .csv or text file containing a list of unique identifiers and have it assign those to a batch of duplicated files (they all have the same contents) that share a slightly different name in the form of a 3-digit number appended as the prefix of a generic name.
For example, let's say my list of files are something like this:
001_test.txt
002_test.txt
003_test.txt
004_test.txt
005_test.txt
etc.
Then my .csv contains an alphabetical list of what I would like those to become:
Alpha.txt
Beta.txt
Charlie.txt
Delta.txt
Echo.txt
etc.
I tried looking at similar examples, but I'm failing miserably trying to tailor them to get it to do the above.
EDIT: I didn't save what I already modified, but here is the baseline script I was messing with:
$file_server = Read-Host "Enter the file server IP address"
$rootFolder = 'C:\TEMP\GPO\source\5'
Get-ChildItem -LiteralPath $rootFolder -Directory |
Where-Object { $_.Name -as [System.Guid] } |
ForEach-Object {
$directory = $_.FullName
(Get-Content "$directory\gpreport.xml") |
ForEach-Object { $_ -replace "99.999.999.999", $file_server } |
Set-Content "$directory\gpreport.xml"
# ... etc
}
I think this is to replace a string inside a file though. I need to replace the file name itself using a list from another file (that is not getting renamed), while not changing the contents of the files that are being renamed.

Answer 1

So you want to rename similar files with those listed in a text file. Ok, here's what you are going to need for my solution (alias listed in parenthesis): Get-Content (GC), Get-ChildItem (GCI), Where (?), Rename-Item, ForEach (%)
$NewNames = GC c:\temp\Namelist.txt #Path, including file name, to list of new names
$Name = "dog.txt" #File name without the 001_ prefix
$Path = "C:\Temp" #Path to search
$i=0
GCI $path | ?{$_.Name -match "\d{3}_$Name"}|%{Rename-Item $_.FullName $NewNames[$i];$i++}
Tested as working. That gets your list of new names and saves it as an array. Then it defines your file name, path, and sets $i to 0 as a counter. Then for each file that matches your pattern it renames it based off of item number $i in the array of new names, and then increments $i up one number and moves to the next file.

Answer 2

I haven't tested this, but it should be pretty close. It assumes you have a CSV with a column named FileNames and that you have at least as many names in that list as there are on disk.
$newNames = Import-Csv newfilenames.csv | Select -ExpandProperty FileNames
$existingFiles = Get-ChildItem c:\someplace
for ($i = 0; $i -lt $existingFiles.count; $i++)
{
Rename-Item -Path $existingFiles[$i].FullName -NewName $newNames[$i]
}
Basically, you create two arrays and using a basic for loop steping through the list of files on disk and pull the name from the corresponding index in the newNames array.

Answer 3

Does your CSV file map the identifiers to the file names?
Identifier,NewName
001,Alpha
002,Beta
If so, you'll need to look up the identifier before renaming the file:
# Define the naming convention
$Suffix = '_test'
$Extension = 'txt'
# Get the files and what to rename them to
$Files = Get-ChildItem "*$Suffix.$Extension"
$Csv = Import-Csv 'Names.csv'
# Rename the files
foreach ($File in $Files) {
$NewName = ($Csv | Where-Object { $File.Name -match '^' + $_.Identifier } | Select-Object -ExpandProperty NewName)
Rename-Item $File "$NewName.$Extension"
}
If your CSV file is just a sequential list of filenames, logicaldiagram's answer is probably more along the lines of what you're looking for.