Current Tramp plans

Current Tramp plans

[Kai Großjohann]

There has been a lot of discussion regarding Tramp.  I would like to
thank all participants for their thoughtful comments.

My summary of the situation:

* The longterm goal is to unify the Tramp and Ange-FTP filenames, and
  to use a format for the filenames which is a superset of the
  Ange-FTP format.

* The Ange-FTP entries are deleted from file-name-handler-alist.

* In certain cases, Tramp forwards the file operations to Ange-FTP.
  These cases include:
  - ftp is explicitly mentioned in the filename
  - the user has said to always use ftp for certain user/host
    combinations
  Additionally, we might want to default to ftp in some cases, such
  as when the user is anonymous.

* Different people have different opinions on what the new format
  should look like.  Proposals for the non-multi case that seem to be
  still in the competition:

  Richard:
    /user@host@method:file
      empty strings for omitted/defaulted components, eg
        /@host@method:file

  Miles (?)
    /user@host#method:file
      numeric methods would be considered ports for ftp

  Kai:
    /[method]user@host:file
      Because I really doubt that square brackets in the user
      name are actually needed.
      And if they are needed, people can just say something like
      /[sm][xx]yy@zz:file
      This will use the sm method, connect to host zz, and use
      the user name "[xx]yy".
      Since square brackets are quite rare, I don't think
      it matters that people have to type a slightly longer
      filename in this case.
    /method#user@host:file
      because `#' is already used by Ange-FTP as a special character

  If there is more than one colon before the first slash, then we
  know that it must be a multi-hop method.  Hence, the colon can be
  reused as a separator between hops.

I would like to proceed in a step-by-step fashion:

* First, I want to make it so that Tramp can forward requests to
  Ange-FTP.

* Then I need to have Tramp accept the port number for the Ange-FTP
  case.

* Then comes an Ange-FTP-like filename format for the non-multi
  methods.

* Then comes a new format for the multi-hop filenames.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[John Wiegley]

>>>>> On Fri Jun 21, Kai writes:

>   Miles (?)
>     /user@host#method:file
>       numeric methods would be considered ports for ftp

I'd like to cast my vote with miles.  I like # as an address extender.

John

Re: Current Tramp plans

[Miles Bader]

storm@cua.dk (Kim F. Storm) writes:
> Also, with ftp method, it is possible to specify the port as in
>         /ftp#user@host#port:file

Whichever syntax is chosen, it should still support `/user@host#port:file'
for backward compatibility.  [It's probably possible with all of them,
though with my recommendation it's trivial... :-)]

-Miles
-- 
Occam's razor split hairs so well, I bought the whole argument!

Re: Current Tramp plans

[Kim F. Storm]

Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann) writes:

> 
>   Kai:
>     /[method]user@host:file
>       Because I really doubt that square brackets in the user
>       name are actually needed.
>       And if they are needed, people can just say something like
>       /[sm][xx]yy@zz:file
>       This will use the sm method, connect to host zz, and use
>       the user name "[xx]yy".
>       Since square brackets are quite rare, I don't think
>       it matters that people have to type a slightly longer
>       filename in this case.

Well, in some contexts (such as ido with regexp matching), using
square brackets in a file name component is "normal" behaviour.

I would recommend using a syntax which does not conflict with
normal regexp syntax.

>     /method#user@host:file
>       because `#' is already used by Ange-FTP as a special character

I think this is a good compromise.

Also, with ftp method, it is possible to specify the port as in
        /ftp#user@host#port:file

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Current Tramp plans

[Richard Stallman]

    I would like to proceed in a step-by-step fashion:

That seems good.

      Miles (?)
	/user@host#method:file
	  numeric methods would be considered ports for ftp

	/method#user@host:file
	  because `#' is already used by Ange-FTP as a special character

Either of these seems good to me.  I have no preference between them.

Re: Current Tramp plans

[Kai Großjohann]

storm@cua.dk (Kim F. Storm) writes:
[...]
> Also, with ftp method, it is possible to specify the port as in
>         /ftp#user@host#port:file
[...]

Would it be possible to choose a syntax that looks more like an URL?

ssh://user@host:port/path/to/file

I think this is something most users are accustomed to. Personally I
find it easier to learn new commands or a new syntax if it sticks
closely to something which I already know and which does something
similar. (That's the good thing with the "|" for multi-hopping. It
looks like piping).

ssh://user@host1:port|telnet://user2@host2/path/to/file

    -- Oliver


PS: Sorry, for breaking the thread. The digest does not preserve the
references header.
-- 
Oliver Scholz               5 Messidor an 210 de la Révolution
Taunusstr. 25               Liberté, Egalité, Fraternité!
60329 Frankfurt a. M.
Tel. (069) 97 40 99 42

Re: Current Tramp plans

[Oliver Scholz]

[...]
> Would it be possible to choose a syntax that looks more like an URL?
[...]

*blushes*

Ups, my apologies for the false "From" in my last mail. I have to
check my Gnus setup ...

    -- Oliver

-- 
Oliver Scholz               5 Messidor an 210 de la Révolution
Taunusstr. 25               Liberté, Egalité, Fraternité!
60329 Frankfurt a. M.
Tel. (069) 97 40 99 42

Re: Current Tramp plans

[Richard Stallman]

    Would it be possible to choose a syntax that looks more like an URL?

URLs use //, and that is inconsistent with an important Emacs filename
reading feature.

Re: Current Tramp plans

[Kai Großjohann]

Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:

> I would like to proceed in a step-by-step fashion:
>
> * First, I want to make it so that Tramp can forward requests to
>   Ange-FTP.

I have now worked on this todo item.  So you can now say C-x C-f
/[ftp/user@host]/path/to/file RET and this will invoke Ange-FTP.

This is committed to the Tramp CVS but not to the Emacs CVS.  I'm not
sure how well tested the code in Emacs CVS should be.

(Another feature that's already done is to select methods based on
user/host combination.  But this is not general filename rewriting as
suggested by somebody.)

[time passes]

Oh, boy.  The code as it stands now won't work.  What I do is to
rewrite the file name to be in Ange-FTP format and then I invoke
ange-ftp-hook-function.  But this means that buffer-file-name in the
new buffers will have the Ange-FTP format.  This, of course, is
highly bogus.

Argh.

Lessee.

I think this can be solved by changing ange-ftp-name-format to be the
same as tramp-file-name-structure.  Then I don't need to change the
filenames at all.

So all the filename rewriting can be taken out again.

> * Then I need to have Tramp accept the port number for the Ange-FTP
>   case.
>
> * Then comes an Ange-FTP-like filename format for the non-multi
>   methods.
>
> * Then comes a new format for the multi-hop filenames.

These three items are still on my todo list.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Sam Steingold]

> * In message <200206240933.g5O9Xft25562@aztec.santafe.edu>
> * On the subject of "Re: Current Tramp plans"
> * Sent on Mon, 24 Jun 2002 03:33:41 -0600 (MDT)
> * Honorable Richard Stallman <rms@gnu.org> writes:
>
>     Would it be possible to choose a syntax that looks more like an URL?
> 
> URLs use //, and that is inconsistent with an important Emacs filename
> reading feature.

This might mean that the feature has to be modified.  Since URLs are
more common than Emacs, I am afraid Emacs will need to adapt.

E.g., "//" would have its special meaning only if it is not preceded
by "^[a-z]+:".


-- 
Sam Steingold (http://www.podval.org/~sds) running RedHat7.2 GNU/Linux
<http://www.camera.org> <http://www.iris.org.il> <http://www.memri.org/>
<http://www.mideasttruth.com/> <http://www.palestine-central.com/links.html>
((lambda (x) (list x (list 'quote x))) '(lambda (x) (list x (list 'quote x))))

Re: Current Tramp plans

[Kai Großjohann]

Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:

> Oh, boy.  The code as it stands now won't work.  What I do is to
> rewrite the file name to be in Ange-FTP format and then I invoke
> ange-ftp-hook-function.  But this means that buffer-file-name in the
> new buffers will have the Ange-FTP format.  This, of course, is
> highly bogus.
>
> Argh.
>
> Lessee.
>
> I think this can be solved by changing ange-ftp-name-format to be the
> same as tramp-file-name-structure.  Then I don't need to change the
> filenames at all.

I've now done this.  It even appears to work.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Richard Stallman]

    This is committed to the Tramp CVS but not to the Emacs CVS.  I'm not
    sure how well tested the code in Emacs CVS should be.

We use our repository for all development.  When you think the code
works, please install it.  Please DO NOT wait until it is "super
tested".

Re: Current Tramp plans

[Richard Stallman]

    > URLs use //, and that is inconsistent with an important Emacs filename
    > reading feature.

    This might mean that the feature has to be modified.  Since URLs are
    more common than Emacs, I am afraid Emacs will need to adapt.

Emacs does not *need to* adapt to anything.

    E.g., "//" would have its special meaning only if it is not preceded
    by "^[a-z]+:".

That might be a workable approach that keeps both features working.
It is worth a try.

Re: Current Tramp plans

[Kai Großjohann]

Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:

> * First, I want to make it so that Tramp can forward requests to
>   Ange-FTP.
>
> * Then I need to have Tramp accept the port number for the Ange-FTP
>   case.

These two items are done.  Because of user request, I've also added a
hack that Tramp groks host names of the form "host#42" in ssh-based
methods, where 42 specifies the port.

> * Then comes an Ange-FTP-like filename format for the non-multi
>   methods.

This is still to do, but ought to be trivial, more or less.

> * Then comes a new format for the multi-hop filenames.

This requires the base64/uuencode autodetection, which I don't have,
yet.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Kai Großjohann]

Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:

> Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:
>
>> * Then comes an Ange-FTP-like filename format for the non-multi
>>   methods.
>
> This is still to do, but ought to be trivial, more or less.

I would like to test things a little bit first.  Therefore, I haven't
made the new setup the default.  Instead, people can put

    (tramp-handle-ange-ftp)

into their init files to install the new filename format and to turn
off Ange-FTP.  Please test this to see whether you like it.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Kim F. Storm]

Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann) writes:

> Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:
> 
> > Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:
> >
> >> * Then comes an Ange-FTP-like filename format for the non-multi
> >>   methods.
> >
> > This is still to do, but ought to be trivial, more or less.
> 
> I would like to test things a little bit first.  Therefore, I haven't
> made the new setup the default.  Instead, people can put
> 
>     (tramp-handle-ange-ftp)
> 
> into their init files to install the new filename format and to turn
> off Ange-FTP.  Please test this to see whether you like it.

If I compare this to ange-ftp on a fresh emacs -q, I see two
advanges to ange-ftp over tramp:

1) With tramp, if I enter
        C-x C-f //kfs:/ TAB
the input is simply truncated to /.  With ange-ftp, I get
completion in the home-directory of / on host `kfs'.

With tramp, I need to enter, e.g. //kfs:/home/ for TAB to work.


2) Tramp does not succeed to connect to the `kfs' host.  Ange-ftp
does. 

The only method which works for me to connect from this system to
`kfs' is `tu'.  The default method used by tramp (rcp) doesn't
work... but there is no indication what is going on.

If at least the echo area would say:  
Connecting to `kfs' using `rsh', I'd have a clue to what's up.


Of course, setting tramp-default-method to tu makes everything work
smoothly, but since it doesn't work out-of-the-box like native
ange-ftp does, I don't think the effect of tramp-handle-ange-ftp
should be the default setting.  But it is a nice option for tramp
users (and ange-ftp users of course :-).


-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Current Tramp plans

[Kai Großjohann]

storm@cua.dk (Kim F. Storm) writes:

> If I compare this to ange-ftp on a fresh emacs -q, I see two
> advanges to ange-ftp over tramp:

Maybe there is a misunderstanding involved.  First of all, Tramp can
forward requests to Ange-FTP -- you just need to use "ftp" as the
method name.  Secondly, the default behavior needs to be twiddled
such that Ange-FTP is used by default in cases where it makes sense.

However, I'm not sure what the new default behavior should be.
Therefore, I made no effort to make sure that Tramp forwards many
requests to Ange-FTP.  Instead, I was kind of hoping you folks would
try different settings and then tell me what you like :-)

One approach would be to do (setq tramp-default-method "ftp").  Then,
filenames that look like Ange-FTP filenames continue to invoke
Ange-FTP, even with (tramp-handle-ange-ftp).  Users would type, say,
C-x C-f /sm#user@host:/path/to/file RET to invoke Tramp with the `sm'
method.


But this does not deal with the filename completion bug.  Hm.  I
never saw that one.  I think it comes from partial completion, but
I'm not sure.  Let me investigate.  Thanks for the bug report.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Kai Großjohann]

Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:

> * The longterm goal is to unify the Tramp and Ange-FTP filenames, and
>   to use a format for the filenames which is a superset of the
>   Ange-FTP format.

Some time ago, I asked you to test whether the Tramp and Ange-FTP
filename integration works.  Kim has responded with a bug which I
hope to have fixed soon (if it isn't fixed already).  So now is the
time to discuss how to proceed.  Please holler if you disagree with
any of the following.

On Emacs, the default will be to unify the filenames.  On XEmacs, the
default will be not to unify, as the XEmacs maintainers don't like
the unification.

If we want to be on the safe side, then Tramp should assume all
filenames that look like "/user@host:path" are Ange-FTP filenames.
This means Emacs behaves as before, and people can customize
tramp-default-method-alist and tramp-default-method to change this
behavior.

If we want to encourage use of Tramp, we could use Tramp by default in
many cases, and Ange-FTP only in some cases.  For example, hosts
matching "^ftp\\." could invoke Ange-FTP (regardless of the user
name), and the users "anonymous" and "ftp" could also invoke Ange-FTP
(regardless of the host name).

Of course, in both cases, people can just specify an explicit method
to override this default decision.

What do you want?

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Sam Steingold]

> * In message <vaflm8kzu8l.fsf@INBOX.auto.emacs.devel.tok.lucy.cs.uni-dortmund.de>
> * On the subject of "Re: Current Tramp plans"
> * Sent on Tue, 09 Jul 2002 19:28:10 +0200
> * Honorable Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann) writes:
>
> Kai.Grossjohann@cs.uni-dortmund.de (Kai Großjohann) writes:
> 
> > * The longterm goal is to unify the Tramp and Ange-FTP filenames, and
> >   to use a format for the filenames which is a superset of the
> >   Ange-FTP format.
> 
> If we want to be on the safe side, then Tramp should assume all
> filenames that look like "/user@host:path" are Ange-FTP filenames.
> This means Emacs behaves as before, and people can customize
> tramp-default-method-alist and tramp-default-method to change this
> behavior.

I would urge you to use URLs (suitably extended)
the Emacs "//" feature can be modified to ignore "^[a-z]*://".

-- 
Sam Steingold (http://www.podval.org/~sds) running RedHat7.2 GNU/Linux
<http://www.camera.org> <http://www.iris.org.il> <http://www.memri.org/>
<http://www.mideasttruth.com/> <http://www.palestine-central.com/links.html>
My inferiority complex is the only thing I can be proud of.

Re: Current Tramp plans

[Stefan Monnier]

> If we want to encourage use of Tramp, we could use Tramp by default in
> many cases, and Ange-FTP only in some cases.  For example, hosts
> matching "^ftp\\." could invoke Ange-FTP (regardless of the user
> name), and the users "anonymous" and "ftp" could also invoke Ange-FTP
> (regardless of the host name).

I'd say: just default to FTP so you get 100% back compatibility.


	Stefan

Re: Current Tramp plans

[Kim F. Storm]

"Stefan Monnier" <monnier+gnu/emacs@rum.cs.yale.edu> writes:

> > If we want to encourage use of Tramp, we could use Tramp by default in
> > many cases, and Ange-FTP only in some cases.  For example, hosts
> > matching "^ftp\\." could invoke Ange-FTP (regardless of the user
> > name), and the users "anonymous" and "ftp" could also invoke Ange-FTP
> > (regardless of the host name).
> 
> I'd say: just default to FTP so you get 100% back compatibility.
> 

I agree.  This will avoid surprises when a user upgrades to 21.4

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Current Tramp plans

[Kai Großjohann]

Sam Steingold <sds@gnu.org> writes:

> I would urge you to use URLs (suitably extended)
> the Emacs "//" feature can be modified to ignore "^[a-z]*://".

I agree that URLs are the way to go.  But I'm afraid that I don't
have time to implement it just yet.  And the Tramp-to-Ange-FTP
forwarding works already.

I put the URL thing on my todo list some time ago, and there it still
is...

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)

Re: Current Tramp plans

[Miles Bader]

Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann) writes:
> I agree that URLs are the way to go.  But I'm afraid that I don't
> have time to implement it just yet.  And the Tramp-to-Ange-FTP
> forwarding works already.

I think it's better to separate the two things anyway; adding tramp
probably won't break anything (much...:-), but URLs are a big enough
change to filename syntax to be more risky.

-Miles
-- 
`Life is a boundless sea of bitterness'

Re: Current Tramp plans

[Richard Stallman]

    If we want to encourage use of Tramp, we could use Tramp by default in
    many cases, and Ange-FTP only in some cases.  For example, hosts
    matching "^ftp\\." could invoke Ange-FTP (regardless of the user
    name), and the users "anonymous" and "ftp" could also invoke Ange-FTP
    (regardless of the host name).

I think we should try this in the CVS version, and see how users react.

Re: Current Tramp plans

[Kai Großjohann]

Richard Stallman <rms@gnu.org> writes:

>     If we want to encourage use of Tramp, we could use Tramp by default in
>     many cases, and Ange-FTP only in some cases.  For example, hosts
>     matching "^ftp\\." could invoke Ange-FTP (regardless of the user
>     name), and the users "anonymous" and "ftp" could also invoke Ange-FTP
>     (regardless of the host name).
>
> I think we should try this in the CVS version, and see how users react.

Done.

kai
-- 
A large number of young women don't trust men with beards.  (BFBS Radio)