NcFTPd general.cf file configuration
Don't forget to restart NcFTPd after modifying the general.cf file.
You can have external programs react to events in near real time. For example, if you wanted to run a script every time there was a file downloaded, you would set download-event-processor to the full pathname of the script. The server will then run that script each time, with various command line arguments.
Obviously I do not recommend using this facility unless you absolutely need to, for two important reasons:
Nevertheless, if you wish to proceed, you can look at the process_ncftpd_event.sh script which comes with the distribution as an example.