How does one pass vars into nested loops in PowerShell? - powershell

Question

I am attempting to write a small PowerShell script to clean up files names from some log dumps, but I seem to be stuck... I have logs dumped from various sources, and the file names seem to be getting garbled up.
I am looking to for name the names of files like so... " Source - Service.log "
Get-ChildItem *.* -Path ~/Desktop/New | ForEach-Object {
while ([string]($_.Name) -notmatch "^[a-z].*" -or [string]($_.Name) -notmatch "^[A-Z].*") {
Rename-Item -NewName { [string]($_.Name).Substring(1) }
}
Write-Host $_.Name
}
The output seems to be erroring out.
Rename-Item : Cannot evaluate parameter 'NewName' because its argument is
specified as a script block and there is no input. A script block cannot be
evaluated without input.
At line:8 char:30
+ Rename-Item -NewName { $File.Substring(1) }
+ ~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : MetadataError: (:) [Rename-Item], ParameterBindingException
+ FullyQualifiedErrorId : ScriptBlockArgumentNoInput,Microsoft.PowerShell.Commands.RenameItemCommand
The Idea is to check the filename to to see if it is a character, and if not remove it, to remove ". - / and whitespace"
The orginal files I am running against are like this:
1. source - data (1).log
100. - source - Data.log
(1) Source - data.log
source - data.log
<space><space> source - data.log
and the result I am looking for from the above is: I am not concerned about the duplicates file names as source and data change day to day and the folder is cleared regularly...
source - data (1).log
source - Data.log
Source - data.log
source - data.log
source - data.log
Can someone tell me how to get past this error?

Answer 1

If your goal is to delete leading non-alpha characters, you can simplify what you're doing:
$files = Get-ChildItem -Path ~\Desktop\New -File
foreach ($file in $files)
{
if ($file.BaseName -notmatch '\S+\s-')
{
$newName = $file.Name -replace '^.+?(?=[a-z])'
$newName = Join-Path $file.DirectoryName $newName
if (Test-Path -Path $newName)
{
Remove-Item -Path $newName
}
$file | Rename-Item -NewName $newName
Write-Verbose $newName
}
}
This will iterate your list and look for your pattern, renaming where necessary. Assumption: the source doesn't have spaces.

Answer 2

This might be helpful: Remove-NonAlphanumericCharFromString.
Knowing how to remove non-alphanumeric, take the base name of the file (name without Path and extension).
Replace unwanted Chars with empty string.
$pattern = '[^a-zA-Z]'
Set-Location <YourDir>
Get-Childitem | Foreach-Object {
Rename-Item -Path ".\$($_.Name)" -NewName "$($_.BaseName -replace $pattern,'')$($_.extension)"
}
Note that above will fail upon a need to overwrite existing file.