M-x term, multi-tty, and terminal emulation problems

M-x term, multi-tty, and terminal emulation problems

[Mark Plaksin]

From time to time I have terminal emulation problems with M-x term in
Emacs.  I'm never certain whether the problems are caused by me and my
environment variables or by term.el itself.  Maybe you can help me figure
it out.

I use the multi-tty branch (based on CVS Emacs) and use M-x term to connect
to lots of different hosts and then run screen on each host.  I put a
compiled version of eterm-color.ti on every host in ~/.terminfo and export
TERMINFO=~/.terminfo.  I compile eterm-color.ti once per OS version (e.g.,
HP-UX, Solaris, Debian, etc) and copy it around.

Here's what I do; what's wrong with it?  If nothing's wrong, presumably
there are problems in term.el and I'll set about debugging those.

1.  Run xterm (TERM=xterm)
2.  Run screen (which sets TERM=screen)
3.  Run multi-tty emacs in TTY mode (i.e., no X window gets created)
4.  Detach from screen and get back to the xterm
5.  Run multi-tty's emacsclient to attach to the Emacs that's already
running.  This time, an X window is created with Emacs inside.
6.  Run a shell inside of Emacs' terminal emulator (TERM=eterm-color)
7.  ssh to a remote host and get a shell (TERM=eterm-color)
8.  Run screen (which sets TERM=screen)
9.  Run vi or some other full screen app.

Thanks for any help!

Re: M-x term, multi-tty, and terminal emulation problems

[Dan Nicolaescu]

Mark Plaksin <happy@mcplaksin.org> writes:

  > >From time to time I have terminal emulation problems with M-x term in
  > Emacs.  I'm never certain whether the problems are caused by me and my
  > environment variables or by term.el itself.  Maybe you can help me figure
  > it out.
  > 
  > I use the multi-tty branch (based on CVS Emacs) and use M-x term to connect
  > to lots of different hosts and then run screen on each host.  I put a
  > compiled version of eterm-color.ti on every host in ~/.terminfo and export
  > TERMINFO=~/.terminfo.  I compile eterm-color.ti once per OS version (e.g.,
  > HP-UX, Solaris, Debian, etc) and copy it around.
  > 
  > Here's what I do; what's wrong with it?  If nothing's wrong, presumably
  > there are problems in term.el and I'll set about debugging those.
  > 
  > 1.  Run xterm (TERM=xterm)
  > 2.  Run screen (which sets TERM=screen)
  > 3.  Run multi-tty emacs in TTY mode (i.e., no X window gets created)
  > 4.  Detach from screen and get back to the xterm
  > 5.  Run multi-tty's emacsclient to attach to the Emacs that's already
  > running.  This time, an X window is created with Emacs inside.
  > 6.  Run a shell inside of Emacs' terminal emulator (TERM=eterm-color)
  > 7.  ssh to a remote host and get a shell (TERM=eterm-color)
  > 8.  Run screen (which sets TERM=screen)
  > 9.  Run vi or some other full screen app.
  > 
  > Thanks for any help!

Does screen use the "csr" terminfo capability? (You can check like this:
M-x term-start-output-log, then run screen then look at the log for
the "csr" terminfo string)
"csr" is one of the things that M-x term has had problems with. Also
smir/rmir might still have issues.

You try removing csr, smir and rmir from eterm-color.ti and see if
you still have problems. 

Note that eterm-color terminfo strings are almost the same as the
xterm ones. If you save the M-x term output log to a file and run 
cat LOG in an xterm with the same number of lines and columns as the
xterm buffer, the xterm should display the same thing as the
M-x term buffer. If it does not, then it's probably an issue with 
M-x term

        --dan