WordPress: Change PDF links in WordPress to link directly to the PDF instead of the attachment page

thePermalinkPDF.php

<?php

defined('ABSPATH') || exit(1);

add_filter('the_permalink', 'thePermalinkPDF');
add_filter('attachment_link', 'thePermalinkPDF');
// Automatically convert permalinks to PDFs in search results to the PDF itself, not the Attachment page
function thePermalinkPDF($permalink){
	global $post;
	if (get_post_mime_type($post->ID) != 'application/pdf') {
		return $permalink;
	}
	// if the result is a PDF, link directly to the file not the attachment page
	return esc_url(wp_get_attachment_url( $post->ID ));
}