Ok, got it.

This annoing thread (sorry) was due to the fact that the only messages that
actually contains the "/" marker are Tauth and Tattach (in the aname). I
still think that using wstat with such marker to atomically move files
among accessible folders would not violate the protocol specification, but
actually it would break existing servers and that's is probably enough to
define it as an extension to the protocol (say 9P2000.a) so that clients
can know if the server supports this semantic or not.
However, as I previously said, I don't think that the world need a new 9p
variant :-D

Now, what's the proper 9p way that a client could use to tell a syntetic
server to atomically move a syntetic file between syntetic folders?
I bet that the answer is a control file receiving rc like commands (or any
other custom, human readable protocol). Would it be correct?

Something like this:

Given
mountpoint/
+ first/
  + moveme.txt
+ second/
+ atomically

Doing
echo mv /first/moveme.txt /second/ > mountpoint/atomically

We optain either the following or a Rerror:
mountpoint/
+ first/
+ second/
  + moveme.txt
+ atomically


Is it the proper way to achieve such kind of operations?


Thanks for your patience... :-)


Giacomo

2015-01-30 23:49 GMT+01:00 Anthony Sorace <a@9srv.net>:

>
> > On Jan 30, 2015, at 10:59 , Giacomo Tesio <giacomo@tesio.it> wrote:
> >
> > It surely would not be conformant to Plan 9 systems, but to the protocol?
>
> No. Joel has it right. Writing a server which allows / in names would mean
> that the "/" you're slipping into a name wouldn't always be a directory
> indicator or name separator. Think of it as the protocol accommodating
> systems which use some other marker.
>
> The relevant point is that the "name" in question (which, as you noticed,
> the protocol allows to contain / even though plan9 doesn't) is the name
> *within a directory*, not a full path name. walk(5) probably gives the best
> explanation of this, or perhaps the discussion of create in open(5).
>
>
>