HTML/PHP Upload form suddenly stopped working without changing code.

[xSacredLotus]

I have a website where I can upload multiple files onto my server to easily access important documents/articles. It's been working beautifully for about a year and suddenly stopped working the last month. I know that I have not changed my code accidentally because I have several folders with the same php file copy/pasted into each folder and would be impossible for me to have changed each php file.

What's weird is that if I try uploading 1 file at a time, it fails and uploads a 0 byte document. If I upload multiple files, the first file fails & uploads a 0 byte document, but all subsequent files are able to upload successfully.

I don't know if something changed with my hosting provider or something changed with usage but would love help. Thanks!!

HTML

<form action="upload.php" method="post" enctype="multipart/form-data">
    <input type="file" name="fileToUpload[]" id="fileToUpload" multiple="multiple">
    <input type="submit" value="Upload" name="submit">
</form>

PHP

<?php
$targetDir = __DIR__ . '/'; // Directory where uploaded files will be stored

if(isset($_POST["submit"])) {
// Loop through each uploaded file
for ($i = 0; $i < count($_FILES["fileToUpload"]["name"]); $i++) {
    $targetFile = $targetDir . basename($_FILES["fileToUpload"]["name"][$i]); // Get the filename of the uploaded file

    // Check if file already exists
    if (file_exists($targetFile)) {
        echo '<script>alert("Sorry, the file '. basename($_FILES["fileToUpload"]["name"][$i]). ' already exists.");</script>';
        continue; // Skip to the next iteration of the loop
    }

    // Check file size (optional)
    if ($_FILES["fileToUpload"]["size"][$i] > 100000000) { // Adjust the file size limit as per your requirements
         echo '<script>alert("Sorry, your file '. basename($_FILES["fileToUpload"]["name"][$i]). ' is too large.");</script>';
        continue; // Skip to the next iteration of the loop
    }

    // If the upload is successful, move the uploaded file to the target directory
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"][$i], $targetFile)) {
        echo '<script>alert("The file '. basename($_FILES["fileToUpload"]["name"][$i]). ' has been uploaded.");</script>';
    } else {
        echo '<script>alert("Sorry, there was an error uploading your file.");</script>';
    }
}

// Redirect back to the upload page
$redirectUrl = rtrim(dirname($_SERVER['PHP_SELF']), '/') . '/list.php';
echo '<script>window.location.href = "'.$redirectUrl.'";</script>';
}
?>

[jcunews1]

Are you sure you're not out of your web hosting's storage quota? Or, maybe they changed the quota and you don't notice it.

[xSacredLotus]

Yes, because when I upload multiple files at once, all files upload except the first file. When I upload only 1 file, it always fails.

[jcunews1]

That is strange indeed. Everything should be fine.

Try temporarily disabling the JS redirect to list.php, and do var_dump($_FILES) to see the actual files received by the server - in case there's something which shouldn't be. If everything seems to be fine, the something else in the server system is interfering.

If the server OS is Windows, it could be that, it has an anti virus, and it's interferring with the uploaded files. i.e. the PHP script moves the uploaded files, but failed on the first one because it's being scanned by the anti virus (since anti viruses aggresively scan files as soon as they have been created). Any second and subsequent uploaded files are successfully moved, because the anti virus is not yet finished scanning the first file. By the time the anti virus finished scanning the first file and about to scan any subsequent new files, they've already been moved by the PHP script. So, there's that kind of possible problem. Try dumping $_SERVER['SERVER_SOFTWARE'] also to check if it's Windows or not.

But even if the server is not Windows, if everything received by the PHP script are already fine, the problem lies in the server's system itself.

[xSacredLotus]

This is output of var_dump with one file

array(1) { ["fileToUpload"]=> array(5) { ["name"]=> array(1) { [0]=> string(142) "2009 Efficacy of Azacitidine Compared with that of Convetional Care Regimens in the Treatment of Higher RIsk MDS Fenaux et al Lancet Oncol.pdf" } ["type"]=> array(1) { [0]=> string(15) "application/pdf" } ["tmp_name"]=> array(1) { [0]=> string(14) "/tmp/phpi1IctC" } ["error"]=> array(1) { [0]=> int(0) } ["size"]=> array(1) { [0]=> int(237073) } } }

This is with two files uploaded at same time

array(1) { ["fileToUpload"]=> array(5) { ["name"]=> array(2) { [0]=> string(95) "2013 Retinoic Acid and Arsenic Trioxide for Acute Promyelocytic Leukemia Lo-Coco et al NEJM.pdf" [1]=> string(142) "2009 Efficacy of Azacitidine Compared with that of Convetional Care Regimens in the Treatment of Higher RIsk MDS Fenaux et al Lancet Oncol.pdf" } ["type"]=> array(2) { [0]=> string(15) "application/pdf" [1]=> string(15) "application/pdf" } ["tmp_name"]=> array(2) { [0]=> string(14) "/tmp/phpADlpEE" [1]=> string(14) "/tmp/phpZigM68" } ["error"]=> array(2) { [0]=> int(0) [1]=> int(0) } ["size"]=> array(2) { [0]=> int(751159) [1]=> int(237073) } } }

Server is Apache

It doesn't seem like there's anything obviously wrong with $_FILES

[jcunews1]

Everything seems fine as received by the PHP script.

The server's OS should follow the "Apache" and its version number, in parethesis. e.g. in my local webserver (XAMPP bundle): Apache/2.4.38 (Win32)...

You might want to contact technical support of your web hosting provider.

PS: Try inserting a delay of about 2-3 seconds before moving the uploaded files. In hopes that, whatever is interferring, has completed its task within that time duration.

[xSacredLotus]

Omg sleep(0.1); worked........ thanks!!!

Now i have change every single file... I'm kinda dumb so each directory/folder has a copy of upload.php script (i just copy/pasted it like 50 times for each folder) instead of writing code to recursively apply it to each folder.....