This note is a description of the FTP server example.
The FTP server example is a minimal implementation of an FTP server. It will serve simultaneous client connections to the server if you configure MAXIMUM_FTP_CLIENTS in example_ftp_server.c.
The server is minimal and therefore has certain limitations. If all you wish to do is store and retrieve files from an SD card managed by the Mass Storage Library, this will do that for you. It will not, however, rename files or act as a full FTP server: that is not its purpose.
This server has no compile-time configuration options. If you wish to remove PUT or GET capability, do this by editing the code. You can extend the capabilities of the server, and customize it for your needs, as it is delivered in source form.