FTP Commands and Extensions

Created

• 2010-01-07

Last Updated

• 2024-04-22

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FTP Commands and Extensions

Expert(s)

• John Klensin

Reference

• RFC 5797: FTP Command and Extension Registry

Note

Note: An IESG Standards Action is allowed to direct IANA to change the Conformance Requirements listed for any entry.

The following commands are part of the base FTP specification RFC 959 and are listed in the registry with the immutable pseudo FEAT code "base".

Mandatory commands:

ABOR, ACCT, ALLO, APPE, CWD, DELE, HELP, LIST, MODE, NLST, NOOP, PASS, PASV, PORT, QUIT, REIN, REST, RETR, RNFR, RNTO, SITE, STAT, STOR, STRU, TYPE, USER

Optional commands:

CDUP, MKD, PWD, RMD, SMNT, STOU, SYST

Note: STD 3 RFC 1123 clarified and updated the status and implementation requirements of these standard FTP commands, and it contains important complementary information for the following commands:

LIST, NLST, PASV, REST, SITE, STOU

The following commands were specified as experimental in an extension to an early version of the FTP specification RFC 775 but later deprecated by RFC 1123, because Standard FTP RFC 959 specifies their standard successors. They are listed in the registry with the immutable pseudo FEAT code "hist".

XCUP, XCWD, XMKD, XPWD, XRMD

Implementation note: Deployed FTP clients still make use of the deprecated commands and most FTP servers support them as aliases for the standard commands.

The following commands were specified as part of the "FOOBAR" IPng effort in RFC 1545 and, later, RFC 1639 and are now obsolete. They are listed in the registry with the immutable pseudo FEAT code "hist".

LPRT, LPSV

Legend for the registry:

• cmd (Command Name)

  Amended versions of commands are tagged with a trailing "+"

• FEAT Code

  Keyword returned in FEAT response line for this command/extension:

  • actual FEAT codes are given in upper case
  • placeholders (pseudo FEAT codes) are shown in lower case
  • "-N/A-" indicates a feature not related to one particular command

  See the "Extension name" clause in Section 2.2 of RFC 5797 for details.

• description

  Brief description of command / extension

• type (Command Type)

  Type or "kind" of command, based on Section 4.1 of RFC 959:

    'a'  ... access control
    'p'  ... parameter setting
    's'  ... service execution
  

  Combinations like 'p/s' are possible.

• conf (Conformance Requirements)

  Expectation for support in modern FTP implementations:

    'm'  ... mandatory to implement
    'o'  ... optional
    'h'  ... historic
  

Available Formats

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