Hashes a directory of files and generates a single SHA1 hash

Get-FolderHash.ps1

Function Get-FolderHash ($Folder) {
          
  Get-ChildItem $folder -Recurse -Exclude "*.psd1" | Where-Object {!$_.psiscontainer} | ForEach-Object {[Byte[]]$contents += [System.IO.File]::ReadAllBytes($_.fullname)}
  $hasher = [System.Security.Cryptography.SHA1]::Create()
  [string]::Join("",$($hasher.ComputeHash($contents) | %{"{0:x2}" -f $_}))
          
}