Verify Files with Checksums and Powershell

VerifyFiles.ps1

param (
  [string]$source = "d:\videoprojects\hwfilm\",
  [string]$dest = "g:\hwfilm\",
  [switch]$debug 
)

$sourceFileList = Get-ChildItem -Path $source -Recurse  | Sort-Object -Property FullName
write-host "Files = $($sourceFileList.Length)"
foreach ($file in $sourceFileList) {
  $fullPath = $file.fullName.Substring($source.Length)
  $destFilePath = Join-Path -Path $dest -ChildPath $fullPath
  $exist = Test-Path $destFilePath
  if ($exist) {
    $sourceHash = Get-FileHash -Path $file.FullName -Algorithm MD5
    $destHash = Get-FileHash -Path $destFilePath -Algorithm MD5
    if ($sourceHash.Hash -eq $destHash.Hash) {
      if ($debug -eq $true) {
        write-host $file.fullName
      }
      else {
        write-host -NoNewline "."
      } 
    }
    else {
      if ($debug -eq $true) { write-host "" } 
      write-host "Failed $($file.name)" -ForegroundColor Red
      Add-Content '.\badFiles.txt' $destFilePath   
    }
  }
}