Ftp-WG: RE: MFXX questions

    Date:        Sun, 8 Feb 2004 06:53:16 
    From:        Wolfgang Zekoll <[email protected]>
    Message-ID:  <[email protected]>

  | So it would be possible to set the modification time of a directory with 
  | MFMT but not to query it with MDTM because MDTM excludes directories?

Note that MDTM doesn't "exclude directories", it says that the
behaviour there is undefined.   That's because different real
filesystems implement directories in vastly different ways, and
there is/was no desire to constrain them to necessarily have the
concept of modification time for a directory, or force one on top
of the particular server's filesystem.

On the other hand, I'd expect the typical unix server's MDTM
implementation to return the standard unix st_mtime for a directory
when queried (that's permissible as undefined behaviour).   It
simply isn't worth the bother to specifically check for the name
being a directory, and exclude it.

Servers on systems where there is no st_mtime, or anything like it,
for a directory, can return an error, or return 00000000000000, or the
current time, or do just about anything else they like (provided only
that they stay within the protocol).

kre

ps: I haven't had time to read the MFXX draft yet, but if it is going to
go anywhere as an IETF work item, it will need to be specified in a way
such that it is implementable on anything which could reasonably implement
an FTP server.