Bulk rename file(s) using Powershell from csv\txt file

Question

As the title suggests I am trying to create a Powershell script to rename multiple files. The script refers to a csv file which contains a string in a csv file "column A". If the result is true then I would like to rename the file from "Column B".

Ive managed to get my code to work based on a string but this is the next stage - can anyone help me please?

Current Code:

Get-ChildItem -Path C:\ -Recurse -ErrorAction SilentlyContinue |
  Where {($_.Name -like "*blah*")} |
  Rename-Item -NewName {[System.IO.Path]::GetFileNameWithoutExtension($_.fullname) + ".BackupFile"}

Thanks as always!

Answer 1

The following assumes that your CSV file contains the file names with extension - adjust as needed.

• Build a hashtable from the CSV whose entries are keyed by Column A values and each contain the corresponding Column B value.

• Filter the Get-ChildItem output with Where-Object to only process files whose name is present as a key in the hashtable.

  • Note that switch -File is added to the Get-ChildItem call below, so as to process files only (not also directory objects).

• Rename each matching file to the value of the relevant hashtable entry.

# Build a hashtable from the CSV that with old-name-new-name pairs.
$ht = [ordered] @{} # Note: you can omit [ordered] in this case.
Import-Csv file.csv |
  ForEach-Object { $ht[$_.'Column A'] = $_.'Column B' }

Get-ChildItem -Path C:\ -File -Recurse -ErrorAction SilentlyContinue |
  Where-Object { $ht.Contains($_.Name) } |
  Rename-Item -NewName { $ht[$_.Name] } -WhatIf

^{Note: The -WhatIf common parameter in the command above previews the operation. Remove -WhatIf once you're sure the operation will do what you want.}

Note: As an alternative to filtering Get-ChildItem output with Where-Object after the fact, you could use the former's -Include parameter as follows:

• -Include $ht.Keys
• However, up to at least PowerShell 7.2.x, -Include is actually slower than a post-filtering solution - see this answer.