<?php
$htmlFiles = ['dosya1.html', 'dosya2.html', 'dosya3.html', '...'];

$pdfFolder = 'pdfdosya/';
foreach ($htmlFiles as $htmlFile) {
    $pdfFile = $pdfFolder . pathinfo($htmlFile, PATHINFO_FILENAME) . '.pdf';
    $command = "wkhtmltopdf $htmlFile $pdfFile";
    exec($command);
}

echo 'PDF : ' . implode(', ', $pdfFiles);
?>