[REM: Query (FILE-LENGTH in particular) of file by name when open]

[Rob MacLachlan <RAM@CMU-CS-C.ARPA>]

Date: 1985 March 20 02:44:29 PST (=GMT-8hr)
From: Robert Elton Maas <REM at IMSSS.SU.EDU>
Sender: REM%IMSSS at SU-SCORE.ARPA (for undeliverable-mail notifications)
Reply-To: REM at MIT-MC.ARPA
To:   RAM
Re:   Query (FILE-LENGTH in particular) of file by name when open
Sent: to SU-AI.ARPA by IMSSS.? via ETHERNET with PUPFTP; 1985-Mar-20 14:51:03 PST (=GMT-8hr)

> Date: Wed, 20 Mar 1985  04:31 EST
> From: Rob MacLachlan <RAM@CMU-CS-C.ARPA>
> Subject: Length of currently-open-for-write file is ambiguous or meaningless
> 
>     The meaning of File-Length on the name of a file which is open for
> write seems operating system dependant, and should be undefined.  Since
> it is in fact this case which I understand to be the basis for not
> allowing file-length on file names, taking this stand would dispose of
> any problems.

May I take it that you mostly agree with me on this point, that the
ambiguity I pointed out (size of file before during or after current
update), and you're saying the default (or only possible
implementation) should be to signal an error if the file you happen to
ask about by name is currently open for write? (Therefore the general
idea of asking about a file by name is well-defined and should be
provided by CL: if the file is open-for-write the query signals an
error, else the query works as expected?)

If so, I think we've reached 2-party concensus (I yield on the other
point you made about query on lisp I/O-channel-object being meaningful).