不过为了和标准的兼容,你最好提供以下命令:
USER PORT RETR ALLO DELE SITE XMKD CDUP FEAT
PASS PASV STOR REST CWD STAT RMD XCUP OPTS
ACCT TYPE APPE RNFR XCWD HELP XRMD STOU AUTH
REIN STRU SMNT RNTO LIST NOOP PWD SIZE PBSZ
QUIT MODE SYST ABOR NLST MKD XPWD MDTM PROT
以及固定的返回值:
如:
220- //connect ok
530- //not log in
331- //user name ok
.... //etc