完整会话
完整会话
S: 220 FTP server ready
C: USER alice
S: 331 Password required
C: PASS ****
S: 230 Login successful.
C: SYST
S: 215 UNIX Type: L8
C: FEAT
S: 211-Features:
S: AUTH TLS
S: PASV
S: UTF8
S: 211 End
C: TYPE I
S: 200 Switching to Binary mode.
C: PASV
S: 227 Entering Passive Mode (10,0,0,5,195,80)
C: RETR report.xlsx
S: 150 Opening BINARY mode data connection
S: 226 Transfer complete.
C: QUIT
S: 221 Goodbye.FEAT 列出的能力是后续命令的依据：要用 UTF-8 文件名看 UTF8 行，要显式加密看 AUTH TLS 行。