5.3. COMMANDS

The commands are Telnet character strings transmitted over the control connections as described in the Section on FTP Commands. The command functions and semantics are described in the Section on Access Control Commands, Transfer Parameter Commands, FTP Service Commands, and Miscellaneous Commands. The command syntax is specified here.

The commands begin with a command code followed by an argument field. The command codes are four or fewer alphabetic characters. Upper and lower case alphabetic characters are to be treated identically. Thus, any of the following may represent the retrieve command:

                  RETR    Retr    retr    ReTr    rETr

This also applies to any symbols representing parameter values, such as A or a for ASCII TYPE. The command codes and the argument fields are separated by one or more spaces.

The argument field consists of a variable length character string ending with the character sequence <CRLF> (Carriage Return, Line Feed) for NVT-ASCII representation; for other negotiated languages a different end of line character might be used. It should be noted that the server is to take no action until the end of line code is received.

The syntax is specified below in NVT-ASCII. All characters in the argument field are ASCII characters including any ASCII represented decimal integers. Square brackets denote an optional argument field. If the option is not taken, the appropriate default is implied.

5.3.1. FTP COMMANDS

The following are the FTP commands:

            USER <SP> <username> <CRLF>
            PASS <SP> <password> <CRLF>
            ACCT <SP> <account-information> <CRLF>
            CWD  <SP> <pathname> <CRLF>
            CDUP <CRLF>
            SMNT <SP> <pathname> <CRLF>
            QUIT <CRLF>
            REIN <CRLF>
            PORT <SP> <host-port> <CRLF>
            PASV <CRLF>
            TYPE <SP> <type-code> <CRLF>
            STRU <SP> <structure-code> <CRLF>
            MODE <SP> <mode-code> <CRLF>
            RETR <SP> <pathname> <CRLF>
            STOR <SP> <pathname> <CRLF>
            STOU <CRLF>
            APPE <SP> <pathname> <CRLF>
            ALLO <SP> <decimal-integer>
                [<SP> R <SP> <decimal-integer>] <CRLF>
            REST <SP> <marker> <CRLF>
            RNFR <SP> <pathname> <CRLF>
            RNTO <SP> <pathname> <CRLF>
            ABOR <CRLF>
            DELE <SP> <pathname> <CRLF>
            RMD  <SP> <pathname> <CRLF>
            MKD  <SP> <pathname> <CRLF>
            PWD  <CRLF>
            LIST [<SP> <pathname>] <CRLF>
            NLST [<SP> <pathname>] <CRLF>
            SITE <SP> <string> <CRLF>
            SYST <CRLF>
            STAT [<SP> <pathname>] <CRLF>
            HELP [<SP> <string>] <CRLF>
            NOOP <CRLF>

5.3.2. FTP COMMAND ARGUMENTS

The syntax of the above argument fields (using BNF notation where applicable) is:

            <username> ::= <string>
            <password> ::= <string>
            <account-information> ::= <string>
            <string> ::= <char> | <char><string>
            <char> ::= any of the 128 ASCII characters except <CR> and
            <LF>
            <marker> ::= <pr-string>
            <pr-string> ::= <pr-char> | <pr-char><pr-string>
            <pr-char> ::= printable characters, any
                          ASCII code 33 through 126
            <byte-size> ::= <number>
            <host-port> ::= <host-number>,<port-number>
            <host-number> ::= <number>,<number>,<number>,<number>
            <port-number> ::= <number>,<number>
            <number> ::= any decimal integer 1 through 255
            <form-code> ::= N | T | C
            <type-code> ::= A [<sp> <form-code>]
                          | E [<sp> <form-code>]
                          | I
                          | L <sp> <byte-size>
            <structure-code> ::= F | R | P
            <mode-code> ::= S | B | C
            <pathname> ::= <string>
            <decimal-integer> ::= any decimal integer