Powershell rename files whilst maintaining the original file order - powershell

Question

I've got a set of files in the following format
I'd like to change the file names to the following format
I've used the following code:
`$i = 21
dir | ForEach-Object {$_ | Rename-Item -NewName ('00816-101998-XX-A-2-50-{0:D3} Detalj.{1}' -f $i++, $_.Extension)}`
This code starts renaming with file name A.10.11.11
How do I get it to start from the first file name i.e. 8.A.10.11.8?
Thank you!

Answer 1

Looking at your question, I think this is what you intend to do.
The list of current filenames should be sorted by the integer value the filenames start with.
Next you want to rename them using a counter that starts with value 21
To do this, you can use a ForEach-Object loop, but the -NewName parameter of Rename-Item can also contain a scriptblock containing the action to perform.
$i = 21
(Get-ChildItem -Path 'D:\Test' -Filter '*.pdf' -File) |
Sort-Object #{Expression = {[int]($_.Name -split ' ')[0]}} |
Rename-Item -NewName { '00816-101998-XX-A-2-50-{0:D3} Detalj{1}' -f $script:i++, $_.Extension }
P.S. The image shows the filename starts with a number followed by a space, while in the question you give an example where the number is followed by a dot .. If that is the case in you file names, change [int]($_.Name -split ' ')[0] into [int]($_.Name -split '\.')[0]
1. We need to address and increment the value of the counter $i using the $script:i scoping syntax, otherwise $i does not exist in the NewName scriptblock
2. To avoid renaming files twice, enclose the Get-ChildItem part in the code in between brackets

Answer 2

param(
$directory = "d:\tmp",
[regex]$rx = "(?<=8.A.10.11.)\d+",
[string]$newPrefix = "00816-101998-XX-A-2-50-"
)
<#
8..20 | ForEach-Object {
$filePath = Join-Path $directory -ChildPath "8.A.10.11.$_.pdf"
Out-File -InputObject "some text" -FilePath $filePath -Encoding default
}
#>
Get-ChildItem $directory | ForEach-Object{
Rename-Item $_.FullName -NewName "$newPrefix$((($rx.Matches($_.BaseName)).value).padleft(3,'0'))$($_.Extension)"
}