How can I rename files by prepending a sequence number to the original file names?

Question

guys does anyone know how can i do this? I am trying to list some files in a numerical order by adding 1, 2, 3 and so on to the beginning of the file names while also keeping the files' original names.

Here are the codes i tried

$nr = 1

Dir -path C:\x\y\deneme | %{Rename-Item $_ -NewName (‘{0} $_.Name.txt’ -f $nr++ )}

dir | select name

This code just orders the files like 1, 2, 3... Without keeping the original names.

$n = 1
Get-ChildItem *.txt | Rename-Item -NewName { $_.Name -replace $_.Name ,'{0} $_.Name' -f $n++}

This one did not work like i thought.

"This one did not work like i thought." - can you tell us how it _did_ work? :-) — Mathias R. Jessen, Jun 24 '21 at 21:27
@MathiasR.Jessen Actually it did nothing at all. It kept the files' names the same. — Burak Yazıcı, Jun 24 '21 at 21:31
@AbrahamZinala I just want to rename them with the addition of numbers but i want to keep the names of the files aside from that. — Burak Yazıcı, Jun 24 '21 at 21:33
@Burak, So you do want to **rename** them in numerical order (*while keeping the original name*) and not just **list** them in numerical order? — Abraham Zinala, Jun 24 '21 at 21:37
@AbrahamZinala Yes exactly. The first code puts them in the numerical order but it also changes the names such as "1 $_.Name.txt", "2 $_.Name.txt"... resulting in a one common name for all the files. — Burak Yazıcı, Jun 24 '21 at 21:46

mklement0 · Accepted Answer · 2021-06-24T22:39:44.093

3

Try the following, which renames all .txt files in the current dir. by prepending a sequence number to them:

$n = 1
Get-ChildItem *.txt | 
  Rename-Item -WhatIf -NewName { '{0} {1}' -f ([ref] $n).Value++, $_.Name }

^{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.}

The ([ref] $n).Value++ trick makes up for the fact that delay-bind script blocks run in a child scope of the caller, where the caller's variables are seen, but applying ++ (or assigning a value) creates a transient, local copy of the variable (see this answer for an overview of PowerShell's scoping rules).
[ref] $n in effect returns a reference to the caller's variable object, whose .Value property can then be updated.

As for what you tried:

'{0} $_.Name.txt', as a single-quoted string, is interpreted verbatim by PowerShell; you cannot embed variable references in such strings; for that you need double-quoting ("...", and you'd also need $(...) in order to embed an expression such as $_.Name) - see the bottom section of this answer for an overview of PowerShell's string literals.

edited Jun 24 '21 at 22:39

answered Jun 24 '21 at 22:24

mklement0

382,024
64
607
775

Well, I was trying to find a way of incrementing `$n` inside the `Rename-Item` ScriptBlock... I guess I learn something new today, again and again lol you're awesome man! – Santiago Squarzon Jun 24 '21 at 22:32
1

@SantiagoSquarzon :) The behavior - and the solution - are definitely obscure; if you're interested in a related conceptual discussion, see [GitHub issue #](https://github.com/PowerShell/PowerShell/issues/7157). – mklement0 Jun 24 '21 at 22:35
1

@AbrahamZinala :) perhaps the GitHub link in my previous comment helps. There's also a less obscure, but more verbose alternative to `([ref] $n).Value++`, and that is `(Get-Variable n -Scope 1).Value++` - and if you can assume that the caller is a script's (top-level) scope, `$script:n++` – mklement0 Jun 24 '21 at 22:38
1

I meant to say, inside the `-Destination {...}` scriptblock of `Copy-Item` which, trying it out works perfect too, except for files are copied to the current dir instead of the dir where `gci` is pointing too (hope it makes sense) hence why I used that `Join-Path` to copy files to where the actual files are. – Santiago Squarzon Jun 24 '21 at 22:39
1

@SantiagoSquarzon, yes, only with `Rename-Item`'s `-NewName` parameter, whose argument must only ever be a file _name_, is the argument guaranteed to refer to the same directory as the input path. – mklement0 Jun 24 '21 at 22:43

score 1 · Answer 2 · answered Jun 24 '21 at 22:10

So yeah, I agree with @Abraham, I don't see a scenario where you can rename the files but also retain the original files without copying them :)

This should do the trick:

$i = 0; Get-ChildItem x:\path\to\files | ForEach-Object {
    $i++
    $destPath = Join-Path $_.DirectoryName -ChildPath "$i $($_.Name)"
    Copy-Item -Path $_.FullName -Destination $destPath
}

Example:

Mode                 LastWriteTime         Length Name                                                                                                                    
----                 -------------         ------ ----                                                                                                                    
-a----         6/24/2021   7:08 PM              2 1 testfile0.txt
-a----         6/24/2021   7:08 PM              2 2 testfile1.txt
-a----         6/24/2021   7:08 PM              2 3 testfile2.txt
-a----         6/24/2021   7:08 PM              2 4 testfile3.txt
-a----         6/24/2021   7:08 PM              2 5 testfile4.txt
-a----         6/24/2021   7:08 PM              2 testfile0.txt  
-a----         6/24/2021   7:08 PM              2 testfile1.txt  
-a----         6/24/2021   7:08 PM              2 testfile2.txt  
-a----         6/24/2021   7:08 PM              2 testfile3.txt  
-a----         6/24/2021   7:08 PM              2 testfile4.txt

How can I rename files by prepending a sequence number to the original file names?

2 Answers2

Linked