Ftp-WG: mdtm and mlsd commands

On Tue, 3 Feb 2004 15:53:18 Wolfgang Zekoll <[email protected]>
wrote:

>> Sounds fine, but I wonder why the working group is ignoring an absent bu=
t
>> apparently needed facility which software developers are now programming
>> around in a common but, of necessity because of the lack of any standard=
,
>> a non-compliant manner.
>
> although I'm not a member of the working group I'll try to give an=20
> explanation based on what I know about FTP.
>
> As author of some FTP server software I simply must follow the original=
=20
> statement, MDTM is query only.  When I considered to implement MDTM-modif=
y=20
> for my server I recognized that the guys who introduced MDTM-modify must=
=20
> have been UN*X guys.  Why?  How can the sever determine if the MDT; comma=
nd=20
> it just got from the client is the query of modify form.  Does the=20
> timestamp belong to the filename or is it the modify timestamp?  This=20
> question can only be answered if blanks are excluded from the filename=20
> character set which is the natural situation for every UN*X admin).  But =
as=20
> far as I know the FTP RFCs don't do this, they allow blanks.  As Linux=20
> admin I can attest that blanks in filenames are bad practice but I also=
=20
> know that today's users expect them.

That explains why MDTM as a setting command is a bad idea but it does not
explain why some other facility for setting file modification dates by
some well considered method is not being proposed for use in its place.

> As server administrator I don't think that I would ever allow a remote=20
> client to modify timestamps of files in the FTP area.  How could I be sur=
e=20
> that my existing software (backup software, archive indexer etc.) can dea=
l=20
> with the situation that a newly modified file has a timestamp in the past=
?

That explains why some host/server administrators might not make this
privilege available to all users with write access, but it does not
explain why those who are willing have no compliant method of doing so.

>  You might take a look of
>
>     http://www.awk-scripting.de/cgi-bin/wiki.cgi/scripting/FtpSync

This is yet more proof that the facility of setting modification dates is
needed.  And, even if only to stamp out the perversion of using MDTM to do
it, would the protocol experts please take note of the need and propose
well designed commands and syntax for software writers to standardize on.

Tony