What role do log files play in diagnosing upload issues on a web server?

Log files play a crucial role in diagnosing upload issues on a web server by recording detailed information about each upload request, including any errors encountered during the process. By analyzing the log files, developers can identify the root cause of the upload problem and take necessary steps to resolve it, such as adjusting server settings or troubleshooting the code responsible for handling file uploads.

// Enable error logging for file uploads
ini_set('log_errors', 1);
ini_set('error_log', '/path/to/upload_errors.log');