Emacs 21 and M-x term

Emacs 21 and M-x term

[Mark Plaksin]

Is there a version of Emacs 21 in which M-x term does the right thing most of
the time?

I've tried many versions including 21.3.50.2 from CVS and they all have
wacky problems.  For example, in 21.3.50.2 it won't use more than half of
the window and ls output is not properly aligned.  It behaves this way
with TERM set to both eterm and vt100.  I've tried starting emacs with -q
and removing my shell's dot files just to make sure I'm not causing the
problem.

Is M-x term in Emacs 21 working well for folks?  If so, what is your
emacs-version and OS?

Currently I use Emacs 20 and M-x term to log into lots of remote machines
via ssh.  I often need to run terminal-based programs like less and vi on
the remote machine.  I'm used to minor terminal emulation problems but most
of them can be fixed by hitting C-l or with small changes to term.el.  The
M-x term problems with Emacs 21 are much worse.  Am I just missing
something?

I've looked at M-x shell and M-x eshell but neither does what I want--I
really love M-x term :)

A side note: The remote machines I connect to run several different OSes.
Almost every time there is a new version of an OS (e.g., HP-UX 11.11 comes
out) there are new terminal emulation problems with M-x term in Emacs 20.
The problems can usually be demonstrated by hitting paging down with C-d
inside of vi.  After that some lines of the file are on the wrong line of
the terminal.  C-l usually gets things displayed correctly.

Is there a good reason for these problems?  I don't fully understand
terminal emulation but I'd have guessed that once vt100 worked it should
work forever.  term.el can be changed to resolve the problems, of course,
but it seems like that shoudn't be required.

Thanks for any help!

Re: Emacs 21 and M-x term

[Lute Kamstra]

Mark Plaksin <happy@usg.edu> writes:

> Is there a version of Emacs 21 in which M-x term does the right
> thing most of the time?
>
> I've tried many versions including 21.3.50.2 from CVS and they all
> have wacky problems.  For example, in 21.3.50.2 it won't use more
> than half of the window and ls output is not properly aligned.  It
> behaves this way with TERM set to both eterm and vt100.  I've tried
> starting emacs with -q and removing my shell's dot files just to
> make sure I'm not causing the problem.

We just fixed the problem of things not being properly aligned in CVS
Emacs.  I do not recognize your problem of term not using more than
half of the window.  Could you check out the latest CVS and see if the
problem still exist?  If so, could you read the bug reporting section
of the Emacs manual (C-h i d m Emacs RET m Bugs RET) and write a bug
report to emacs-pretest-bug@gnu.org?

Thanks,

  Lute.

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Re: Emacs 21 and M-x term

[Mark Plaksin]

Lute Kamstra <Lute.Kamstra@cwi.nl> writes:

> We just fixed the problem of things not being properly aligned in CVS
> Emacs.  I do not recognize your problem of term not using more than
> half of the window.  Could you check out the latest CVS and see if the
> problem still exist?  If so, could you read the bug reporting section
> of the Emacs manual (C-h i d m Emacs RET m Bugs RET) and write a bug
> report to emacs-pretest-bug@gnu.org?

My main problem seems to have been using Debian unstable.  With Debian
woody and CVS Emacs, it's much better.  Almost all of the rest of my
problems went away when I compiled eterm.ti on all of the hosts and set
TERM to eterm.

In the past CVS Emacs has behaved the same in both woody and unstable.
With CVS Emacs in unstable I still have the "only uses half the screen"
problem.  There are other problems as well even with TERM set to eterm.

I'm guessing that you don't want bug reports about Debian unstable since it
is unstable.  Do you have any clues about where I might look for the
solution on my own?

Thanks for your response and your work on Emacs!

Re: Emacs 21 and M-x term

[Lute Kamstra]

Mark Plaksin <happy@usg.edu> writes:

> Lute Kamstra <Lute.Kamstra@cwi.nl> writes:
>
>> We just fixed the problem of things not being properly aligned in
>> CVS Emacs.  I do not recognize your problem of term not using more
>> than half of the window.  Could you check out the latest CVS and
>> see if the problem still exist?  If so, could you read the bug
>> reporting section of the Emacs manual (C-h i d m Emacs RET m Bugs
>> RET) and write a bug report to emacs-pretest-bug@gnu.org?
>
> My main problem seems to have been using Debian unstable.  With
> Debian woody and CVS Emacs, it's much better.  Almost all of the
> rest of my problems went away when I compiled eterm.ti on all of the
> hosts and set TERM to eterm.

So, which problems remain?

> In the past CVS Emacs has behaved the same in both woody and
> unstable.  With CVS Emacs in unstable I still have the "only uses
> half the screen" problem.  There are other problems as well even
> with TERM set to eterm.
>
> I'm guessing that you don't want bug reports about Debian unstable
> since it is unstable.

It is possible that there are bugs in Emacs that show up on Debian
unstable and not on Debian stable.  If you are reasonably sure that
the problems you are experiencing are due to a bug in Emacs, we very
much like to hear from you.  (Take a look a the Emacs Manual for some
guidelines with respect to bug reporting.)

> Do you have any clues about where I might look for the solution on
> my own?

I don't know much about terminals, but maybe you can try to debug it?
The Emacs Lisp Reference Manual (included with CVS Emacs) has a
chapter on debugging lisp.  You could use the source level debugger to
see what goes wrong on Debian unstable.  (Additionally, you can use
the debugger on Debian stable to see how things should go.)

  Lute.

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Re: Emacs 21 and M-x term

[Mark Plaksin]

Lute Kamstra <Lute.Kamstra@cwi.nl> writes:

>> My main problem seems to have been using Debian unstable.  With
>> Debian woody and CVS Emacs, it's much better.  Almost all of the
>> rest of my problems went away when I compiled eterm.ti on all of the
>> hosts and set TERM to eterm.
>
> So, which problems remain?

After more testing, it turns out that it isn't stable vs. unstable.
Instead it is courier fonts vs. fixed fonts.  With Emacs 20 I can use
either one; with CVS Emacs courier causes problems.  Specifically, with
CVS Emacs emacs -q M-x term ls with a fixed font works as expected but
with a courier font the columns don't line up correctly.

The two fonts I am using are:
-adobe-courier-medium-r-*-*-20-*-100-100-*-*-*-*
-*-fixed-*-*-*-*-24-*-100-100-*-120-iso8859-1

I don't care whether I use fixed or courier so I switched to fixed for
CVS Emacs.

Now that I can use CVS Emacs for everyday work, I will compile a list
of the remaining problems and do what I can to help with debugging.

One problem so far: ssh to an HP-UX 11.00 system, set TERM to eterm, and
run vi.  C-d does *almost* what you'd expect but the bottom half of the
screen is off by one line.  When I hit C-l the bottom half of the lines
move up one line.

Thanks for your help :)

Re: Emacs 21 and M-x term

[Lute Kamstra]

Mark Plaksin <happy@usg.edu> writes:

> After more testing, it turns out that it isn't stable vs. unstable.
> Instead it is courier fonts vs. fixed fonts.  With Emacs 20 I can
> use either one; with CVS Emacs courier causes problems.
> Specifically, with CVS Emacs emacs -q M-x term ls with a fixed font
> works as expected but with a courier font the columns don't line up
> correctly.
>
> The two fonts I am using are:
> -adobe-courier-medium-r-*-*-20-*-100-100-*-*-*-*
> -*-fixed-*-*-*-*-24-*-100-100-*-120-iso8859-1

I cannot reproduce your problem.  I tried both fonts.  Both work well
in combination with term.  Maybe I don't quite understand the problem
you are experiencing.  What exactly do you mean with "columns don't
line up correctly"?  It sounds as if you use a variable width font,
but both fonts you mention are fixed width.  Could you elaborate?

> Now that I can use CVS Emacs for everyday work, I will compile a list
> of the remaining problems and do what I can to help with debugging.

Great.

> One problem so far: ssh to an HP-UX 11.00 system, set TERM to eterm,
> and run vi.

So you run vi from within Emacs.  Interesting.  ;-)

> C-d does *almost* what you'd expect but the bottom half of the
> screen is off by one line.  When I hit C-l the bottom half of the
> lines move up one line.

Are you talking about C-d sent to Emacs or sent to vi?  (I know 0.0
about vi.)


  Lute.


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Re: Emacs 21 and M-x term

[Mark Plaksin]

Lute Kamstra <Lute.Kamstra@cwi.nl> writes:

> I cannot reproduce your problem.  

I can't reliably reproduce the problem either but it happens most of the
time.  When I can reproduce it I'll send details.

> I tried both fonts.  Both work well in combination with term.  Maybe I
> don't quite understand the problem you are experiencing.  What exactly
> do you mean with "columns don't line up correctly"?  

Here's an example.  When it works it looks like this:
~/emacs/cvs:water$ ls c*
config.bat     config.log      config.sub*  configure.in
config.guess*  config.status*  configure*

When it doesn't work it looks something like this:
~/emacs/cvs:water$ ls c*
config.bat     config.log  config.sub*  configure.in
config.guess*  config.status*  configure*

In the second example config.sub doesn't start in the right column.

> It sounds as if you use a variable width font, but both fonts you
> mention are fixed width.  Could you elaborate?

I thought (and think) they are fixed width too so I don't understand
why the fonts matter.  I don't know much about fonts.

>> Now that I can use CVS Emacs for everyday work, I will compile a list
>> of the remaining problems and do what I can to help with debugging.
>
> Great.

I won't get the list compiled until next week but it will come.

>> One problem so far: ssh to an HP-UX 11.00 system, set TERM to eterm,
>> and run vi.
>
> So you run vi from within Emacs.  Interesting.  ;-)

Ha!  My main use for term is to connect to remote machines and do system
administration.  Maybe gnuserv or TRAMP could be used to edit files as
root on remote machines but I haven't tried it.  I also haven't thought
through whether it's a good idea or not.  Even if I had it all set up,
there would always be new machines on which it was not yet set up :)
Sysadmins *must* know some vi anyhow.  Don't get me wrong though I'd
love to be doing *everything* in Emacs!

>> C-d does *almost* what you'd expect but the bottom half of the
>> screen is off by one line.  When I hit C-l the bottom half of the
>> lines move up one line.
>
> Are you talking about C-d sent to Emacs or sent to vi?  (I know 0.0
> about vi.)

C-d is like C-v in Emacs except it only moves down half a page.  I'm
typing C-d inside an Emacs term and it's getting sent to the vi process
on the remote host.  C-l in vi redraws the screen.

Re: Emacs 21 and M-x term

[Lute Kamstra]

Mark Plaksin <happy@usg.edu> writes:

> Here's an example.  When it works it looks like this:
> ~/emacs/cvs:water$ ls c*
> config.bat     config.log      config.sub*  configure.in
> config.guess*  config.status*  configure*
>
> When it doesn't work it looks something like this:
> ~/emacs/cvs:water$ ls c*
> config.bat     config.log  config.sub*  configure.in
> config.guess*  config.status*  configure*
>
> In the second example config.sub doesn't start in the right column.

Strange that this would have anything to do with the font.  Could you
debug term-emulate-terminal (in lisp/term.el) to see which STR is
passed to it?  This is probably easiest in line mode (C-c C-j),
assuming the problematic behavior occurs in line mode as well.  To
debug a function, type C-u C-M-x when point is in the function
definition to instrument it.  Edebug will then be started whenever the
function is called.

>> So you run vi from within Emacs.  Interesting.  ;-)
>
> Ha!  My main use for term is to connect to remote machines and do system
> administration.  Maybe gnuserv or TRAMP could be used to edit files as
> root on remote machines but I haven't tried it.  I also haven't thought
> through whether it's a good idea or not.  Even if I had it all set up,
> there would always be new machines on which it was not yet set up :)
> Sysadmins *must* know some vi anyhow.  Don't get me wrong though I'd
> love to be doing *everything* in Emacs!

You could start Emacs on the remote machine.  Emacs within Emacs, oh
joy!  Since you are doing system administration, it's your job to
install The One True Editor on the machines in your care, right?  ;-)

By the way, TRAMP has been integrated into CVS Emacs.


  Lute.

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