daybreak.ps1

$hactool = "$PSScriptRoot\hactool.exe"
$prodkeys = "$PSScriptRoot\prod.keys"
$firmware = "$PSScriptRoot\Firmware 10.1.0\"
$files = Get-ChildItem $firmware -Filter *.nca
$numfiles = 0
foreach ($file in $files) {
    $hacout = & $hactool -k $prodkeys -i $firmware$file | Out-String
    if($hacout -like '*Content Type:                       Meta*') {
        Get-Item $firmware$file | Rename-Item -Path $firmware$file -NewName { $_.Name -replace '.nca','.cnmt.nca' }
        $numfiles++
    }
}
Write-Host "Renamed "$numfiles " ncas"

For deejay87's "Failed to match key" issue: SciresM/hactool#79.

Also my own little script:

iterateFiles -iname '*.nca' ! -iname '*.cnmt.nca' | while read file;
  if hactool -i "$file" | grep -iP '\bContent Type:\s+Meta\b';
    echo "$file";
  end
end