PowerShell bulk replacing a specific character and rename file extension - powershell

Question

I need to bulk rename files in a file share that
contain a specific character, namely a tilde ~ and
have the file extension in capital letters or none at all.
The goal would be to replace the tilde with a simple -, keep the file extension, if there is one, but transform it into lowercase letters.
I've had success with the first part of the script that finds the files
$PATH = "\\<Fileservername>\<Folder>\"
$pattern = "*~*"
Get-ChildItem $PATH -Recurse | where {$_.Name -like $pattern}
What I'm struggling with is the second part of the script the renaming.
I've found two topics here:
Powershell renaming a specific Character
PowerShell Regex Bulk Replace Filenames
I haven't been able to adapt those solutions to my need plus there may be additional steps to take in order to convert the given file name from capital letters to lowercase letters or skip this if the file has no file extension.
An example would be to rename ACUJLH~H to ACUJLH-H and KYA3BM~Q.PDF to KYA3BM-Q.pdf.

Answer 1

Here's my contribution. I have added the -File switch to the Get-ChildItem cmdlet so it will look for files only and will not try and handle directory names.
Also, I have changed the replace pattern to ~+ so files that have repeating tildes will be replaced with a single - character. (KYA3BM~~~~Q.PDF becomes KYA3BM-Q.pdf)
$path = "D:\Code\PowerShell\StackOverflow"
$pattern = "*~*"
Get-ChildItem $path -Recurse -File | Where-Object {$_.Name -like $pattern} |
ForEach-Object {
$directory = $_.DirectoryName # or [System.IO.Path]::GetDirectoryName($_.FullName) or use Split-Path $_.FullName -Parent
$filename = $_.BaseName -replace '~+', '-' # or [System.IO.Path]::GetFileNameWithoutExtension($_.Name) -replace '~+', '-'
$extension = $_.Extension # or [System.IO.Path]::GetExtension($_.Name)
if (![string]::IsNullOrEmpty($extension)) { $filename += $extension.ToLower() }
$newname = Join-Path -Path $directory -ChildPath $filename
Rename-Item -LiteralPath $_.FullName -NewName $newName -Force
}

Answer 2

You will need to filter files those meets your criteria. Then using ForEach-Object compare for extensions and build new file names for every found item. Finally, using Rename-Item cmdlet you make the change.
$PATH = '\\<Fileservername>\<Folder>\'
Get-ChildItem $PATH -Recurse -Include '*~*' | ForEach-Object {
[String]$Extension = [System.IO.Path]::GetExtension($_)
[String]$NewFileName = [System.IO.Path]::GetFileNameWithoutExtension($_.Name) -replace '~','-'
if ($Extension){ $NewFileName += $Extension.ToLower() }
Rename-Item $_.FullName $(Join-Path ([System.IO.Path]::GetDirectoryName($_)) $NewFileName) -Force
}