rfc765.txt

RFC 的详细文档！

            command, as some sites may require an account for login and
            others only for specific access, such as storing files.  In
            the latter case the command may arrive at any time.

            There are reply codes to differentiate these cases for the
            automaton: when account information is required for login,
            the response to a successful PASSword command is reply code
            332.  On the other hand, if account information is NOT
            required for login, the reply to a successful PASSword
            command is 230; and if the account information is needed for
            a command issued later in the dialogue, the server should






                                   22


                                                                        
IEN 149                                                        June 1980
RFC 765                                           File Transfer Protocol



            return a 332 or 532 reply depending on whether he stores
            (pending receipt of the ACCounT command) or discards the
            command, respectively.

         REINITIALIZE (REIN)

            This command terminates a USER, flushing all I/O and account
            information, except to allow any transfer in progress to be
            completed.  All parameters are reset to the default settings
            and the TELNET connection is left open.  This is identical
            to the state in which a user finds himself immediately after
            the TELNET connection is opened.  A USER command may be
            expected to follow.

         LOGOUT (QUIT)

            This command terminates a USER and if file transfer is not
            in progress, the server closes the TELNET connection.  If
            file transfer is in progress, the connection will remain
            open for result response and the server will then close it.
            If the user-process is transferring files for several USERs
            but does not wish to close and then reopen connections for
            each, then the REIN command should be used instead of QUIT.

            An unexpected close on the TELNET connection will cause the
            server to take the effective action of an abort (ABOR) and a
            logout (QUIT).

      TRANSFER PARAMETER COMMANDS

         All data transfer parameters have default values, and the
         commands specifying data transfer parameters are required only
         if the default parameter values are to be changed.  The default
         value is the last specified value, or if no value has been
         specified, the standard default value as stated here.  This
         implies that the server must "remember" the applicable default
         values.  The commands may be in any order except that they must
         precede the FTP service request.  The following commands
         specify data transfer parameters.

         DATA PORT (PORT)

            The argument is a HOST-PORT specification for the data port
            to be used in data connection.  There defaults for both the
            user and server data ports, and under normal circumstances
            this command and its reply are not needed.  If this command




                                   23


                                                                        
June 1980                                                        IEN 149
File Transfer Protocol                                           RFC 765



            is used  the argument is the concatenation of a 32-bit
            internet host address and a 16-bit TCP port address.  This
            address information is broken into 8-bit fields and the
            value of each field is transmitted as a decimal number (in
            character string representation).  The fields are separated
            by commas.  A port command would be:

               PORT h1,h2,h3,h4,p1,p2

            where, h1 is the high order 8 bits of the internet host
            address.

         PASSIVE (PASV)

            This command requests the server-DTP to "listen" on a data
            port (which is not its default data port) and to wait for a
            connection rather than initiate one upon receipt of a
            transfer command.  The response to this command includes the
            host and port address this server is listening on.

         REPRESENTATION TYPE (TYPE)

            The argument specifies the representation type as described
            in the Section on Data Representation and Storage.  Several
            types take a second parameter.  The first parameter is
            denoted by a single TELNET character, as is the second
            Format parameter for ASCII and EBCDIC; the second parameter
            for local byte is a decimal integer to indicate Bytesize.
            The parameters are separated by a <SP> (Space, ASCII code
            32.).

            The following codes are assigned for type:

                         \    /
               A - ASCII |    | N - Non-print
                         |-><-| T - TELNET format effectors
               E - EBCDIC|    | C - Carriage Control (ASA)
                         /    \
               I - Image
               
               L <byte size> - Local byte Byte size

            The default representation type is ASCII Non-print.  If the
            Format parameter is changed, and later just the first
            argument is changed, Format then returns to the Non-print
            default.




                                   24


                                                                        
IEN 149                                                        June 1980
RFC 765                                           File Transfer Protocol



         FILE STRUCTURE (STRU)

            The argument is a single TELNET character code specifying
            file structure described in the Section on Data
            Representation and Storage.

            The following codes are assigned for structure:

               F - File (no record structure)
               R - Record structure
               P - Page structure

            The default structure is File.

         TRANSFER MODE (MODE)

            The argument is a single TELNET character code specifying
            the data transfer modes described in the Section on
            Transmission Modes.

            The following codes are assigned for transfer modes:

               S - Stream
               B - Block
               C - Compressed

            The default transfer mode is Stream.

      FTP SERVICE COMMANDS

         The FTP service commands define the file transfer or the file
         system function requested by the user.  The argument of an FTP
         service command will normally be a pathname.  The syntax of
         pathnames must conform to server site conventions (with
         standard defaults applicable), and the language conventions of
         the TELNET connection.  The suggested default handling is to
         use the last specified device, directory or file name, or the
         standard default defined for local users.  The commands may be
         in any order except that a "rename from" command must be
         followed by a "rename to" command and the restart command must
         be followed by the interrupted service command.  The data, when
         transferred in response to FTP service commands, shall always
         be sent over the data connection, except for certain
         informative replies.  The following commands specify FTP
         service requests:





                                   25


                                                                        
June 1980                                                        IEN 149
File Transfer Protocol                                           RFC 765



         RETRIEVE (RETR)

            This command causes the server-DTP to transfer a copy of the
            file, specified in the pathname, to the server- or user-DTP
            at the other end of the data connection.  The status and
            contents of the file at the server site shall be unaffected.

         STORE (STOR)

            This command causes the server-DTP to accept the data
            transferred via the data connection and to store the data as
            a file at the server site.  If the file specified in the
            pathname exists at the server site then its contents shall
            be replaced by the data being transferred.  A new file is
            created at the server site if the file specified in the
            pathname does not already exist.

         APPEND (with create) (APPE)

            This command causes the server-DTP to accept the data
            transferred via the data connection and to store the data in
            a file at the server site.  If the file specified in the
            pathname exists at the server site, then the data shall be
            appended to that file; otherwise the file specified in the
            pathname shall be created at the server site.

         MAIL FILE (MLFL)

            The intent of this command is to enable a user at the user
            site to mail data (in form of a file) to another user at the
            server site.  It should be noted that the files to be mailed
            are transmitted via the data connection in ASCII or EBCDIC
            type.  (It is the user's responsibility to ensure that the
            type is correct.)  These files should be inserted into the
            destination user's mailbox by the server in accordance with
            serving Host mail conventions.  The mail may be marked as
            sent from the particular user HOST and the user specified by
            the 'USER' command.  The argument field may contain a Host
            system ident, or it may be empty.  If the argument field is
            empty or blank (one or more spaces), then the mail is
            destined for a printer or other designated place for general
            delivery site mail.








                                   26


                                                                        
IEN 149                                                        June 1980
RFC 765                                           File Transfer Protocol



         MAIL (MAIL)

            This command allows a user to send mail that is NOT in a
            file over the TELNET connection.  The argument field may
            contain system ident, or it may be empty.  The ident is
            defined as above for the MLFL command.  After the 'MAIL'
            command is received, the server is to treat the following
            lines as text of the mail sent by the user.  The mail text
            is to be terminated by a line containing only a single
            period, that is, the character sequence "CRLF.CRLF".  It is
            suggested that a modest volume of mail service should be
            free; i.e., it may be entered before a USER command.

         MAIL SEND TO TERMINAL (MSND)

            This command is like the MAIL command, except that the data
            is displayed on the addressed user's terminal, if such
            access is currently allowed, otherwise an error is returned.

         MAIL SEND TO TERMINAL OR MAILBOX (MSOM)

            This command is like the MAIL command, except that the data
            is displayed on the addressed user's terminal, if such
            access is currently allowed, otherwise the data is placed in
            the user's mailbox.

         MAIL SEND TO TERMINAL AND MAILBOX (MSAM)

            This command is like the MAIL command, except that the data
            is displayed on the addressed user's terminal, if such
            access is currently allowed, and, in any case, the data is
            placed in the user's mailbox.

         MAIL RECIPIENT SCHEME QUESTION (MRSQ)

            This FTP command is used to select a scheme for the
            transmission of mail to several users at the same host.  The
            schemes are to list the recipients first, or to send the
            mail first.

         MAIL RECIPIENT (MRCP)

            This command is used to identify the individual recipients
            of the mail in the transmission of mail for multiple users
            at one host.





                                   27


                                                                        
June