PHP file name and extension restoration - php

Question

I have a bunch of files in a directory with random 16 digit file-names and no file extensions, e.g. 'RTSWZci59BqXDqaV'
I have a database that through various calls and relationships I can find the files original name, extension and content type. 'Original', as these were all once files that were uploaded to a server via a website (that I did not build).
I've written a small piece of code to loop through the files and re-write them all to their original file-name and extension. This works to a degree, in that .txt files work, but PDF / word docs are corrupted and images are scrambled / fuzzy / off-colour.
It is definitely not the case that these files are just broken.
A part of the website remains that downloads individual files:
header('Cache-Control: no-cache, must-revalidate');
header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
header('Pragma:');
header('Content-type: '.$originalContentType);
header('Content-Disposition: attachment; filename="'.$originalFileName'].'.'.$originalExt'].'"');
header('Content-Length: '.filesize(FILE_FOLDER.$fileName));
readfile(FILE_FOLDER.$fileName);
My code where I am trying to convert each file back to something use-able is some database stuff, some loops and then this:
#rename($directory.$fileName, $directory.$originalFileName.'.'.$originalExt);
I've also tried using copy(), and can't even get a single file to download by setting headers.
Is there something obvious that I should be doing differently here? Must it be the case that some other encoding happened to the image when it was uploaded? Can I do anything to these files once I've got them off of the server?

Answer 1

The name of a file cannot make it corrupted, other than attempting to open it with the wrong program / import filter (e.g. trying to open a JPEG as a Word Document or vice versa).
If the images look nearly right, then it sounds like some data corruption has occurred, and you have the right filenames but not the right contents.
I'm presuming you exported them from some previous location which is why they have dummy names? Perhaps during that process the files have been truncated to a particular size, or where a NULL byte was encountered. Or perhaps certain bytes have been interpreted as characters in some particular text encoding, rather than copied as-is.
If they were in a database, it's possible that you selected them using a driver or query type not designed for handling binary data.

Answer 2

I ended up just replicating the single header download method I described in my example, with some JS that downloaded the next file every few seconds through the browser.
By far not the most elegant solution, but it saved me some time.
<script type="text/javascript">
$(document).ready ( function(){
var delay = 1000;
<?php
$a=0;
foreach($files as $file) { ?>
delay=delay+3000;
setTimeout(function (){ window.open("<?php echo $file; ?>"); }, delay);
<?php } ?>
});
</script>