an inconvenient difference in Emacs 22

an inconvenient difference in Emacs 22

[Steve Newcomb]

In older versions of Emacs, 

    C-X C-F ENTER 

has always re-read the file associated with the buffer the user was
already in.

In my shiny new Emacs 22, this doesn't happen.  Instead,
what is opened is the directory in which the current buffer's
file lives.  Apparently, one has to type in the name of the
file in order to refresh it from disk:

    C-X C-F (name of file, explicitly typed in) ENTER

This lowers the productivity of telephone-mediated collaborative
editing sessions.  In such sessions, participants need to update the
current file from disk, many, many times -- whenever any other
participant changes it.  To have to type in the file name all over
again, every time somebody changes something, is insupportably
burdensome.

I would urge that this important defaulting behavior be present
by default in Emacs 22, as it has always been.  If that's
not possible for some reason, I would appreciate instructions
on how to restore this behavior in Emacs 22.  Thanks in advance!

-- Steve

Steven R. Newcomb, Consultant
Coolheads Consulting

Co-editor, Topic Maps International Standard (ISO/IEC 13250)
Co-editor, draft Topic Maps -- Reference Model (ISO/IEC 13250-5)

srn@coolheads.com
http://www.coolheads.com

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5, 2007, no electronic communications of innocent citizens can be
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acting on fears promoted by fraudulently-elected rogues, has allowed
absolute power (codenamed "unitary Executive") to be usurped by those
very same rogues.  Hail Caesar!)

RE: an inconvenient difference in Emacs 22

[Drew Adams]

> In older versions of Emacs, C-X C-F ENTER has always re-read the
> file associated with the buffer the user was already in.
>
> In my shiny new Emacs 22, this doesn't happen.  Instead,
> what is opened is the directory

I believe that this was done deliberately.

FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of another
keystroke). The `C-n' retrieves the default value, which is the name of the
current file.

If you often revert a buffer (e.g. re-read a file), you might consider
binding `revert-buffer' to a quick key sequence - I use `S-f1', for
instance.

Re: an inconvenient difference in Emacs 22

[Denis Bueno]

On 9/20/07, Drew Adams <drew.adams@oracle.com> wrote:
> > In older versions of Emacs, C-X C-F ENTER has always re-read the
> > file associated with the buffer the user was already in.
> >
> > In my shiny new Emacs 22, this doesn't happen.  Instead,
> > what is opened is the directory
>
> I believe that this was done deliberately.
>
> FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of another
> keystroke). The `C-n' retrieves the default value, which is the name of the
> current file.

I believe you can also do `C-c C-v RET'.

-- 
                              Denis

Re: an inconvenient difference in Emacs 22

[Eric Hanchrow]

M-x auto-revert-mode RET 
-- 
It is possible that with more experience and maturity Scorsese
will direct more polished, finished films ...
        -- Roger Ebert, 1969

Re: an inconvenient difference in Emacs 22

[Markus Triska]

"Denis Bueno" <dbueno@gmail.com> writes:

> I believe you can also do `C-c C-v RET'.

It's C-x C-v RET.

If the file has changed on disk, editing attempts will make Emacs ask
you what to do; press 'r' to refresh. My suggestion: 'r r'.

Re: an inconvenient difference in Emacs 22

[Steve Newcomb]

"Drew Adams" <drew.adams@oracle.com> writes:

> > "Steve Newcomb" <srn@coolheads.com> wrote:
> > 
> > In older versions of Emacs, C-X C-F ENTER has always re-read the
> > file associated with the buffer the user was already in.
> >
> > In my shiny new Emacs 22, this doesn't happen.  Instead,
> > what is opened is the directory
> 
> I believe that this was done deliberately.
> 
> FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of another
> keystroke). The `C-n' retrieves the default value, which is the name of the
> current file.

FYI: That didn't work.

From: "Denis Bueno" <dbueno@gmail.com>
> I believe you can also do `C-c C-v RET'.

FYI:  That didn't work either.

I suspect these things didn't work because of my own .emacs, which
is old and woolly.

> If you often revert a buffer (e.g. re-read a file), you might consider
> binding `revert-buffer' to a quick key sequence - I use `S-f1', for
> instance.

Good idea.  That worked!

Thanks for these suggestions.

In the end, an even better approach, at least for our purposes, may be
global-auto-revert-mode.  I am chagrined to discover that this mode
has been around for a while, and I just didn't know it.  Until I read
your suggestions, I had never understood that, in the jargon of Emacs,
"revert-buffer", means "update the buffer".  

I'm curious about this usage of the word "revert".  "Revert" normally
connotes some sort of retrograde motion.  As far as I know, it never
connotes forward motion at all, much less forward motion undertaken to
catch up with someone else's forward motion.  But, until I'm
corrected, that's how I'll understand "revert" in the context of Emacs.

-- Steve

Re: an inconvenient difference in Emacs 22

[Kevin Rodgers]

Steve Newcomb wrote:
> I'm curious about this usage of the word "revert".  "Revert" normally
> connotes some sort of retrograde motion.  As far as I know, it never
> connotes forward motion at all, much less forward motion undertaken to
> catch up with someone else's forward motion.  But, until I'm
> corrected, that's how I'll understand "revert" in the context of Emacs.

I think that revert-buffer was originally developed for the case where
the user wanted to discard the changes he'd made in a modified but
unsaved buffer, reverting its contents to the original disk file.

-- 
Kevin Rodgers
Denver, Colorado, USA

Re: an inconvenient difference in Emacs 22

[Ken Goldman]

Kevin Rodgers wrote:
> Steve Newcomb wrote:
> 
>> I'm curious about this usage of the word "revert".  "Revert" normally
>> connotes some sort of retrograde motion.  As far as I know, it never
>> connotes forward motion at all, much less forward motion undertaken to
>> catch up with someone else's forward motion.  But, until I'm
>> corrected, that's how I'll understand "revert" in the context of Emacs.
> 
> 
> I think that revert-buffer was originally developed for the case where
> the user wanted to discard the changes he'd made in a modified but
> unsaved buffer, reverting its contents to the original disk file.

Personally, I find that it's great for watching log files.

Re: an inconvenient difference in Emacs 22

[David Combs]

In article <mailman.1152.1190461055.18990.help-gnu-emacs@gnu.org>,
Kevin Rodgers  <kevin.d.rodgers@gmail.com> wrote:
>Steve Newcomb wrote:
>> I'm curious about this usage of the word "revert".  "Revert" normally
>> connotes some sort of retrograde motion.  As far as I know, it never
>> connotes forward motion at all, much less forward motion undertaken to
>> catch up with someone else's forward motion.  But, until I'm
>> corrected, that's how I'll understand "revert" in the context of Emacs.
>
>I think that revert-buffer was originally developed for the case where
>the user wanted to discard the changes he'd made in a modified but
>unsaved buffer, reverting its contents to the original disk file.
>
>-- 
>Kevin Rodgers
>Denver, Colorado, USA
>
>
Not still a use?  

  (It's *all* that I (know enough to) use it for)

David

Re: an inconvenient difference in Emacs 22

[Giorgos Keramidas]

On 21 Sep 2007 22:21:54 -0400, Steve Newcomb <srn@coolheads.com> wrote:
> In the end, an even better approach, at least for our purposes, may be
> global-auto-revert-mode.  I am chagrined to discover that this mode
> has been around for a while, and I just didn't know it.  Until I read
> your suggestions, I had never understood that, in the jargon of Emacs,
> "revert-buffer", means "update the buffer".

The name was probably chosen because it "reverts any in-memory
modifications the buffer includes, and reloads its contents to what is
stored on disk."

It may seem a bit unintuitive, but now you know it's there and another
cool feature of Emacs can make your every day life easier :-)

> I'm curious about this usage of the word "revert".  "Revert" normally
> connotes some sort of retrograde motion.  As far as I know, it never
> connotes forward motion at all, much less forward motion undertaken to
> catch up with someone else's forward motion.  But, until I'm
> corrected, that's how I'll understand "revert" in the context of
> Emacs.

"revert" is also used in the Source Code Management world.  There is at
least one particular use of "revert" which matches precisely the meaning
of "revert" in Emacs lore.

<somewhat-off-topic-but-probably-useful-to-know>

In the Perforce SCM, every file of a local workspace is checked-out as
read-only[1].  Before making local changes, Perforce users are expected
to run "p4 edit filename" or "p4 open filename", to notify the central
repository server that they are going to make changes to the file.

Once a file is "opened", it becomes a part of the active changelist and
it no longer receives updates from the repository, even if another
developer modifies it.  It is something like "a local buffer for a
historical copy of the file's contents".

If the developer wants to throw away all local changes, and synchronize
her copy with the latest version of the file in the repository, then the
appropriate incantation is:

    p4 revert filename

This does not necessarily "revert" the file contents to the version
which had been historically checked out, but it "reverts the local file
copy to the latest version of the file in the repository".

When a Perforce user runs "p4 revert", the same sort of "forward
movement" you describe with Emacs buffer contents happens if another
developer has checked-in changes in the mean time :-)

Notes
*****

[1] There is an option to check out read-write copies, but it is
    generally frowned upon and it makes life somewhat harder down the
    road.  But that's irrelevant here.

</somewhat-off-topic-but-probably-useful-to-know>

Re: an inconvenient difference in Emacs 22

[Tim X]

Steve Newcomb <srn@coolheads.com> writes:

> "Drew Adams" <drew.adams@oracle.com> writes:
>
>> > "Steve Newcomb" <srn@coolheads.com> wrote:
>> > 
>> > In older versions of Emacs, C-X C-F ENTER has always re-read the
>> > file associated with the buffer the user was already in.
>> >
>> > In my shiny new Emacs 22, this doesn't happen.  Instead,
>> > what is opened is the directory
>> 
>> I believe that this was done deliberately.
>> 
>> FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of another
>> keystroke). The `C-n' retrieves the default value, which is the name of the
>> current file.
>
> FYI: That didn't work.
>
> From: "Denis Bueno" <dbueno@gmail.com>
>> I believe you can also do `C-c C-v RET'.
>
> FYI:  That didn't work either.
>
> I suspect these things didn't work because of my own .emacs, which
> is old and woolly.
>
>> If you often revert a buffer (e.g. re-read a file), you might consider
>> binding `revert-buffer' to a quick key sequence - I use `S-f1', for
>> instance.
>
> Good idea.  That worked!
>
> Thanks for these suggestions.
>
> In the end, an even better approach, at least for our purposes, may be
> global-auto-revert-mode.  I am chagrined to discover that this mode
> has been around for a while, and I just didn't know it.  Until I read
> your suggestions, I had never understood that, in the jargon of Emacs,
> "revert-buffer", means "update the buffer".  
>
> I'm curious about this usage of the word "revert".  "Revert" normally
> connotes some sort of retrograde motion.  As far as I know, it never
> connotes forward motion at all, much less forward motion undertaken to
> catch up with someone else's forward motion.  But, until I'm
> corrected, that's how I'll understand "revert" in the context of Emacs.
>
> -- Steve

I think the 'revert' terminology is used because what you are doing is
reverting the buffer back to what is on disk. So really, it is a backwards
move - its only that you are actively updating the file on disk that it has
the appearance of being a forward move. In other situations, you may decide
that the changes you have made in the buffer were all wrong and you want to
revert it back to what was in the original disk file. I can't think of
another term that would cover both the situations of reverting back to the
contents in a static file and updating to reflect updates in the original
file (given they both involve essentially the same mechanism). 

Tim

-- 
tcross (at) rapttech dot com dot au

Re: an inconvenient difference in Emacs 22

[Harald Hanche-Olsen]

+ "Drew Adams" <drew.adams@oracle.com>:

> FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of
> another keystroke). The `C-n' retrieves the default value, which is
> the name of the current file.

C-n should be M-n, apparently.  Now you have to move another finger.  ;->

-- 
* Harald Hanche-Olsen     <URL:http://www.math.ntnu.no/~hanche/>
- It is undesirable to believe a proposition
  when there is no ground whatsoever for supposing it is true.
  -- Bertrand Russell

RE: an inconvenient difference in Emacs 22

[Drew Adams]

> > FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of
> > another keystroke). The `C-n' retrieves the default value, which is
> > the name of the current file.
> 
> C-n should be M-n, apparently.  Now you have to move another finger.  ;->

Oops, yes, that's what I meant. Thanks for correcting.

Re: an inconvenient difference in Emacs 22

[Dave Pawson]

On 21/09/2007, Drew Adams <drew.adams@oracle.com> wrote:
> > > FWIW, you can do `C-x C-f C-n' to get what you want (at the cost of
> > > another keystroke). The `C-n' retrieves the default value, which is
> > > the name of the current file.
> >
> > C-n should be M-n, apparently.  Now you have to move another finger.  ;->
>
> Oops, yes, that's what I meant. Thanks for correcting.

Whatever. Thanks people.
Like Steve that's something I've missed | not found in emacs.
I've only one app that does that on my setup.

Now I have two :-)

regards


-- 
Dave Pawson
XSLT XSL-FO FAQ.
http://www.dpawson.co.uk

Re: an inconvenient difference in Emacs 22

[Joost Kremers]

Steve Newcomb wrote:
> This lowers the productivity of telephone-mediated collaborative
> editing sessions.  In such sessions, participants need to update the
> current file from disk, many, many times -- whenever any other
> participant changes it.

why don't you use auto-revert-mode?


-- 
Joost Kremers                                      joostkremers@yahoo.com
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)

Re: an inconvenient difference in Emacs 22

[Joe Fineman]

Steve Newcomb <srn@coolheads.com> writes:

> In older versions of Emacs, 
>
>     C-X C-F ENTER 
>
> has always re-read the file associated with the buffer the user was
> already in.
>
> In my shiny new Emacs 22, this doesn't happen.  Instead, what is
> opened is the directory in which the current buffer's file lives.

That's what I've always thought ought to happen.  When I get around to
upgrading my Emacs, I will give three cheers.

Different strokes for different folks.  My Emacs never communicates
with anybody but me.  Time after time, when I was in a file and wanted
to look at the directory, I have forgotten to delete the slash at the
end of the prompt, with the result that nothing happened.  I always
wondered what the idea was.
-- 
---  Joe Fineman    joe_f@verizon.net

||:  Nonloving kindness is the more admirable kind.  :||