Renaming files with PowerShell

Question

Hello there,

I'm totally newbie at PowerShell and I'm trying to rename some files with it (there are many folders with many many files each). I found a script out of the box that almost fits my needs, and I was able to change it accordingly. My code that works is:

ls | %{$extension = $.Extension; Rename-Item $ $number$extension; $number++}

$number is set previously = 0. What it does is basically naming the files from 0 to the number of files that the folder has.

I tried to change that line removing the variable, like this:

ls | %{Rename-Item $_ $number$_.Extension; $number++}

But it doesn't work, instead of naming a file from "example.txt" to "0.txt", it goes to "0example.txt.Extension", so it seems to me that the property $_.Extension isn't being read correctly. Can someone please explain to me what is happening?

Answer 1

Hi @JOSÉ LUÍS DE BRITO CARDOSO ,

please try this:

$number = 0  
ls | %{Rename-Item $_ "$number$($_.Extension)";  $number++}  

Just compare this and your approach. It's just a matter of syntax.

Btw.: Your code might look shorter but is bascically the same:
ls is an alias of Get-ChildItem
% is an alias of Foreach-Object

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(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten

Answer 2

Code that works:

ls | %{$extension = $_.Extension; Rename-Item $_ $number$extension; $number++}

Code that doesn't

ls | %{Rename-Item $_ $number$_.Extension; $number++}

Answer 3

Hi @JOSÉ LUÍS DE BRITO CARDOSO ,

please try this and see if it's working for you:

$folder = "C:\Junk\3"  
$count = 0  
Get-ChildItem -Path $folder | ForEach-Object {  
  $ext = $_.Extension  
  Rename-Item -Path $_.FullName -NewName "$count$ext"  
  $count += 1  
}  

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(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten

Answer 4

Hi @Andreas Baumgarten ,

Yes, it does work, but that isn't exactly the point, I'd like to know why the code below doesn't... Since it is basically a shorter version of the code that works, I'm curious what am I missing...

ls | %{Rename-Item $_ $number$_.Extension; $number++}

Answer 5

Hi @Andreas Baumgarten ,

Oh I see, so it was a syntax problem, this works....

 ls | %{Rename-Item $_ "$number$($_.Extension)";  $number++}  

This doesn't, and I thought they were all the same '-'

 ls | %{Rename-Item $_ "$number($_.Extension)";  $number++}  
  
 ls | %{Rename-Item $_ "$number$_.Extension";  $number++}  
  
 ls | %{Rename-Item $_ $number$_.Extension;  $number++}  

Thank you very much!!