Re: [ftpext] End byte of transfer in FTP

[Richard Koenning <[e-mail]>]

John C Klensin wrote:

> Yes.  I'm still not convinced trying to specify fragments of
> stream files is a good idea at all but, if it is to be done,
> let's do it with a new command and very clearly-specified
> semantics.  Remember that, if transfers are done in TYPE I, 
> 
> 	-- not only can one have any of the usual
> 	line-separation characters, but one can have other sorts
> 	of record markers or length-delimited lines or blocks.
> 	
> 	-- if Unicode is being sent consistent with the base
> 	spec), one gets internal storage forms (often UTF-16LE
> 	or UTF-16BE) not only UTF-8, and certainly does not get
> 	one octet per character.
> 
> So specifying fragments clearly is not a trivial piece of work
> unless the new command also requires a new file STRUcture
> variation.

I don't see a problem on FTP protocol level, with TYPE I the transfered 
data is an unstructured stream of bytes, in which REST currently defines 
a starting point and in which a RANGE specification would additionally 
define an endpoint.
FTP clients and servers operating on files which are not simply a stream 
of bytes but e.g. have some length-delimited record structure may have 
hard work to do, but this problem exists already with the current REST 
command.

-- 
Dr. Richard W. Könning
Fujitsu Technology Solutions GmbH