214 Help message.\n\
USER <SP> <username> <CRLF>     : Specify user for authentication\n\
PASS <SP> <password> <CRLF>     : Specify password for authentication\n\
CWD  <SP> <pathname> <CRLF>     : Change working directory\n\
CDUP <CRLF>                     : Change working directory to parent directory\n\
QUIT <CRLF>                     : Disconnection\n\
DELE <SP> <pathname> <CRLF>     : Delete file on the server\n\
PWD  <CRLF>                     : Print working directory\n\
PASV <CRLF>                     : Enable \"passive\" mode for data transfer\n\
PORT <SP> <host-port> <CRLF>    : Enable \"active\" mode for data transfer\n\
HELP [<SP> <string>] <CRLF>     : List available commands\n\
NOOP <CRLF>                     : Do nothing\n\
RETR <SP> <pathname> <CRLF>     : Download file from server to client\n\
STOR <SP> <pathname> <CRLF>     : Upload file from client to server\n\
LIST [<SP> <pathname>] <CRLF>   : List files in the current working directory\r\n",
        802)