HS FTP is a C/C++ library written in C which implements the client side of the File Transfer Protocol over TCP socket layer according to RFC 959. The library allows a user application to connect to remote FTP servers, traverse server directory structure and send and receive files. The HS FTP protocol module supports passive mode data connections, user / password authentication and a number of commonly used FTP commands: USER, PASS, TYPE, PASV, LIST, CWD, RETR, STOR, MKD, RMD, DELE

Features
- FTP Client RFC 959 operation
- Full C/C++ source code included
- Server name resolution
- Concurrent FTP client sessions
- Passive mode, firewall friendly
- User / password authentication
- Asynchronous Operation
- Thread safe
- recursive folder operations

To connect to remote FTP server, the user application calls HsFtpCliConnect, supplying connection parameters, such as remote FTP server name or IP address, username and password for authentication etc and a pointer to callback function that the HS FTP module uses to communicate with the user code.

When the control FTP connection is established and HS FTP has successfully passed user / password FTP account authentication phase, the user application is asynchronously notified via user event callback function with HS_FTPCLI_USR_EV_LOGGEDIN event. The user application can now request remote FTP server directory listing using HsFtpCliList function, change directory HsFtpCliChdir, transfer files with HsFtpCliSendFile and HsFtpCliGetFile.

More info at
http://www.hillstone-software/hs_ftp_details.htm