> uploadtext_

<?php

// Configuration
const UPLOAD_DIR = __DIR__ . '/uploads/'; // Ensure this directory exists and is writable, outside web root is ideal
const MAX_FILE_SIZE = 5 * 1024 * 1024; // 5 MB
const ALLOWED_MIME_TYPES = ['image/jpeg', 'image/png', 'image/gif', 'application/pdf'];
const ALLOWED_EXTENSIONS = ['jpg', 'jpeg', 'png', 'gif', 'pdf'];

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['fileUpload'])) {
    $file = $_FILES['fileUpload'];

    // 1. Check for upload errors
    if ($file['error'] !== UPLOAD_ERR_OK) {
        die('File upload error: ' . $file['error']);
    }

    // 2. Validate file size
    if ($file['size'] > MAX_FILE_SIZE) {
        die('File is too large.');
    }

    // 3. Validate MIME type (from PHP and potentially Finfo for better security)
    $finfo = new finfo(FILEINFO_MIME_TYPE);
    $mime_type = $finfo->file($file['tmp_name']);
    if (!in_array($mime_type, ALLOWED_MIME_TYPES)) {
        die('Invalid file type detected: ' . htmlspecialchars($mime_type));
    }

    // 4. Validate file extension (after MIME type for extra check)
    $file_extension = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
    if (!in_array($file_extension, ALLOWED_EXTENSIONS)) {
        die('Invalid file extension.');
    }

    // 5. Generate a unique and safe filename
    $new_filename = uniqid('upload_', true) . '.' . $file_extension;
    $destination = UPLOAD_DIR . $new_filename;

    // 6. Move the uploaded file to its final destination
    if (move_uploaded_file($file['tmp_name'], $destination)) {
        echo 'File uploaded successfully: ' . htmlspecialchars($new_filename);
        // IMPORTANT: Never directly serve user-uploaded files without proper sanitization
        // and setting appropriate Content-Type headers.
    } else {
        die('Failed to move uploaded file.');
    }
}

?>

<!-- Example HTML form for upload -->
<form action="" method="post" enctype="multipart/form-data">
    <input type="file" name="fileUpload">
    <input type="submit" value="Upload File">
</form>