PowerShell to convert directory of PowerPoints into PDFs. Adapted from http://mike.clackjones.com/convert-directory-of-pptx-into-pdf-in-powershell/

pptx2pdf.ps1

$ppt = new-object -com powerpoint.application
$opt = [Microsoft.Office.Interop.PowerPoint.PpSaveAsFileType]::ppSaveAsPDF

foreach($ifile in $(Get-ChildItem '.' -Filter '*.pptx')) {
    $ifile = $ifile.FullName
    $pres = $ppt.Presentations.Open($ifile)
    $pathname = split-path $ifile
    $filename = split-path $ifile -leaf
    $file = $filename.split(".")[0]
    $ofile = $pathname + "\\" + $file + ".pdf"
    $pres.SaveAs($ofile, $opt)
    $pres.Close()
}