This is a basic script that helps cleanup a series of unused constants in a single file by scanning all *.cs files from a folder to try to find any usages. If not found, it will get commented out and the dev will be able to easily Find/Replace all commented lines with an empty line after verifying that nothing is broken. It uses text parsing, so…

DelUnusedConstants.ps1

$fileToCheck = 'C:\SourceCode\BitCollectors.WinFormsControls\BitCollectors.WinFormsControls\Common\Win32Native.cs'
$fileToOutput = 'C:\Temp\Win32Native.new.cs'
$fileToBackup = 'C:\Temp\Win32Native.old.cs'
$folderToLookIn = 'C:\SourceCode\BitCollectors.WinFormsControls\BitCollectors.WinFormsControls'
$constRegex = '^\s*[^\/]\s*((internal|private|public|protected)?\s+const\s+[a-zA-Z0-9]+)?\s+([A-Z]{1}[a-zA-Z0-9_]+)\s*\=.*(;|,)\s*$'

$csFiles = Get-ChildItem -Path $folderToLookIn -Recurse -Filter '*.cs'

#region Functions
Function OnLoad {
    Clear-Host

    Write-Output 'Starting'

    $execTime = (Measure-Command { $unusedMembers = GetUnusedMembers } )
    Write-Output "GetUnusedMembers: $($execTime.TotalSeconds)"

    $null = New-Item -Path 'C:\TEMP\testMembers.txt' -Force
    $unusedMembers | Add-Content 'C:\TEMP\testMembers.txt'

    $execTime = (Measure-Command { RemoveMembersFromFileAndSave -members $unusedMembers })
    Write-Output "RemoveMembersFromFileAndSave: $($execTime.TotalSeconds)"

    Write-Output "Done"
}

Function GetParsedMembers {
  param(
    [System.String]$fileToCheck
  )

  # 1.27
  Get-Content -Path $fileToCheck | 
    % { if ($_ -cmatch $constRegex) { , $matches[3] } } | 
      Select-Object -Unique
}

Function GetUnusedMembers {
  $csFiles | 
    Get-Content | 
        ? { $_ -notmatch '^\s*\/(\/|\*)' }| 
            % { $fileContents += $_ }

  GetParsedMembers -fileToCheck $fileToCheck | 
    Where-Object {
      ([regex]::matches($fileContents, [regex]::escape($_)).Count) -lt 2
    }
}

Function RemoveMembersFromFileAndSave {
  param (
    [System.String[]]$members
  )

  Copy-Item $fileToCheck -Destination $fileToBackup -Force
  
  $writer = [System.IO.StreamWriter] $fileToOutput
  try { 
    $reader = [System.IO.File]::OpenText($fileToBackup)
    try {
      for(;;) {
          $line = $reader.ReadLine()
          if ($line -eq $null) { 
              break }

          if ($line -cmatch $constRegex -and $members -contains $matches[3]) {
            $line = "// -CONST- $($line)" }

          $writer.WriteLine($line)
      }
  } finally {
      $reader.Close()
  }} finally {
      $writer.Close()
  }
}
#endregion

#region Entry
OnLoad
#endregion