PHP display PDF from internal file server - php

Question

I have an internal server running PHP and an internal file directory with some work instructions pdfs for our technicians to read from. I'm trying to add a link to those pdf files so the technicians can click on the link and open the pdf in the browser.
So I have echo "' . "Work Instruction Link"
and I get Security Error: Content at http://LocalServer:50563/workInstructions.php may not load or link to file:///path/to/workInstruction.pdf
I understand the security risk of not being able to access the local files of a user from a web page, but I don't understand why I can paste the same file url into the address bar and the file will display on the web page. How are those two mechanisms different?
Is there a way to make that link work while serving it from my PHP server, or am I just going about the problem completely wrong? Is there something wrong with my formatting or syntax that I'm not catching?
I noticed that the error response does not contain the server in the file name. I don't exactly know what that means, or why that is the case.
My question is not answered by this post: html-File URL "Not allowed to load local resource in the internet browser because 1. it is asking within classic ASP which is a very different technology from PHP and 2. While it does have the same error message it does not explain how to have a link to files hosted on the same server as the webserver.
I have also tried the answer to this question: Point a link to a certain server
but it did not work for me when i try to convert "FILE://fileserver/path/to/workInstruction.pdf" to "Http://fileserver/path/to/workInstruction.pdf" I'm guessing because it's a file server and not a webserver that the pdf is located on.
To further pinpoint my question, is there a way in PHP to serve a link to a file hosted on a local server that the user can click and open a PDF in the browser?

Answer 1

For anyone else coming to this looking for an answer I have found this answer worked for me:
PHP-Display PDF on browser
Essentially I take the file path of the PDF I'm trying to load that I get from my fileserver and redirect to a new php file that reads the file and displays it in a new tab
The php file that contains the link will have something like this:
echo ''.$wi_num.'';
My workInstruction.php looks like this:
<?php
$filename= $_GET['filename'];
$filePath= $_GET['filepath'];
header('Content-type:application/pdf');
header('Content-disposition: inline; filename="'.$filename.'"');
header('content-Transfer-Encoding:binary');
header('Accept-Ranges:bytes');
#readfile($filePath);
?>