| 1 | How do you move an uploaded file from its temporary location to a permanent storage location using move_uploaded_file? PHP › File Upload Handling | PHP | File Upload Handling | Beginner |
| 2 | How should you validate an uploaded file's type and size before accepting it, and why is checking only the file extension considered insufficient for security? PHP › File Upload Handling | PHP | File Upload Handling | Intermediate |
| 3 | How does PHP handle file uploads submitted through an HTML form, and what information does the $_FILES superglobal provide? PHP › File Upload Handling | PHP | File Upload Handling | Beginner |
| 4 | How do you handle multiple file uploads submitted from a single form field, and what does the resulting $_FILES array structure look like? PHP › File Upload Handling | PHP | File Upload Handling | Intermediate |
| 5 | How should uploaded file names be sanitized and randomized to avoid security risks and naming conflicts when storing files on the server? PHP › File Upload Handling | PHP | File Upload Handling | Intermediate |
| 6 | What security risks arise from allowing file uploads into a publicly accessible directory, and how do you prevent uploaded files from being executed as scripts? PHP › File Upload Handling | PHP | File Upload Handling | Advanced |
| 7 | How should a large scale application design its file upload architecture to handle high volumes of uploads reliably, including virus scanning and offloading storage to a dedicated service? PHP › File Upload Handling | PHP | File Upload Handling | Advanced |
| 8 | What security risks are associated with file handling operations that involve user supplied file paths, and how does path traversal attack prevention work? PHP › File Handling & File System Functions | PHP | File Handling & File System Functions | Advanced |
| 9 | What HTTP status code and response should be returned when an upload fails validation (wrong type, too large, missing file)? ASP.NET Core › File Uploads & Streaming Large Files | ASP.NET Core | File Uploads & Streaming Large Files | Beginner |
| 10 | How do you validate an uploaded file's actual content type (not just its client-supplied extension or Content-Type header) to prevent malicious file uploads? ASP.NET Core › File Uploads & Streaming Large Files | ASP.NET Core | File Uploads & Streaming Large Files | Intermediate |
| 11 | How would you implement resumable/chunked file uploads in Node.js to handle very large files over unreliable network connections? Node.js › File Uploads & Media Processing | Node.js | File Uploads & Media Processing | Advanced |
| 12 | How do you check whether a file or directory exists, and how do you retrieve useful metadata like a file's size or last modified time? PHP › File Handling & File System Functions | PHP | File Handling & File System Functions | Intermediate |
| 13 | How would you validate an uploaded image's actual dimensions and reject ones that don't meet minimum or maximum size requirements? Node.js › File Uploads & Media Processing | Node.js | File Uploads & Media Processing | Intermediate |
| 14 | How do you work with directories in PHP, including listing their contents, creating new directories, and recursively deleting them? PHP › File Handling & File System Functions | PHP | File Handling & File System Functions | Intermediate |
| 15 | How would you handle file uploads through a form using a server action in Next.js? Next.js › Form Handling & Validation in Next.js | Next.js | Form Handling & Validation in Next.js | Advanced |
| 16 | What is the difference between fs.rename() and manually copying then deleting a file, particularly across different filesystems or drives? Node.js › File System (fs) Module | Node.js | File System (fs) Module | Intermediate |
| 17 | Why is validating and sanitizing file uploads important, and what specific checks should you perform to prevent an attacker from uploading a malicious file? PHP › Security | PHP | Security | Intermediate |
| 18 | How would you use try-with-resources combined with multiple chained I/O wrapper classes (like FileInputStream wrapped in BufferedInputStream wrapped in GZIPInputStream) to correctly read a compressed file while ensuring all layers are properly closed? Java › I/O & NIO | Java | I/O & NIO | Intermediate |
| 19 | How do you handle exceptions that occur during response streaming, after the response has already partially started sending to the client? ASP.NET Core › Error Handling | ASP.NET Core | Error Handling | Advanced |
| 20 | How do you send an HTML formatted email with an embedded image or attachment using PHPMailer? PHP › Email Sending in PHP (PHPMailer & SMTP) | PHP | Email Sending in PHP (PHPMailer & SMTP) | Intermediate |