remote [ssh] Backspace] key gives me "^?"

[Mel]

On Saturday 15 September 2007 23:24:54 Gary Kline wrote:
> On Sat, Sep 15, 2007 at 10:54:34PM +0200, Mel wrote:
> > On Saturday 15 September 2007 22:28:22 Gary Kline wrote:
> > > On Sat, Sep 15, 2007 at 10:58:52AM -0700, Garrett Cooper wrote:
> > > > Chad Perrin wrote:
> > > > >On Fri, Sep 14, 2007 at 06:01:03PM -0700, Gary Kline wrote:
> > > > >>	Sometimes when I ssh from a remote server and edit a file with
> > > > >>	vi, my [Backspace keys] are not interpretered correctly.
> > > > >>	Instead of erasing characters and backing up one byte and
> > > > >>	clearing that character my cursor moves forward.
> > > > >>
> > > > >>	Example: typing "This" as "thos" and backspacing to the 'o'
> > > > >>	I'll see "thos^?^?"    Can anybody 'splain what idiot thing i'm
> > > > >>	doing wrong and how to fix it?
> > > > >>
> > > > >>	tia,
> > > > >>
> > > > >>	gary
> > > > >
> > > > >I tend to guess you're using a terminal emulator from within X when
> > > > >logging in remotely -- probably aterm or another rxvt-based terminal
> > > > >emulator.  I had similar problems.  I don't recall my exact fix, but
> > > > > it involved a two-tiered approach:
> > > > >
> > > > >  1. set a behavior using stty
> > >
> > > 	Trying to use stty failed... .
> > >
> > > > >  2. change a setting in the aterm makefile before installing from
> > > > > ports
> > > > >
> > > > >My reference to the aterm makefile in part of the solution is
> > > > > because I suffered this problem when I used aterm as my terminal
> > > > > emulator of choice.  I have since then switched to rxvt-unicode
> > > > > (also known as urxvt) as my preferred terminal emulator, however,
> > > > > and no longer have this problem (as well as no longer having funny
> > > > > broken ASCII spew on my screen when reading email that contains
> > > > > unicode characters).
> > > > >
> > > > >Best o' luck.  Let us know if you think this pseudo-solution doesn't
> > > > >apply to you so we can help you brainstorm other diagnoses of your
> > > > >problem.
> > > >
> > > >    It's because the TERM'inal emulation / keyboard layout's not
> > > > meshing. ^?--as I discovered after I asked the question ~8 months
> > > > ago--is a remnant DEC keyboard mapping, when if properly addressed by
> > > > setting TERM or fixing the keyboard layout to a standard ASCII
> > > > keyboard layout, the problem will go away.
> > > >
> > > > In shorter terms, if you...
> > > >    1. ... switch over to TERM=xterm (assuming that the terminal prog
> > > > you're using is xterm compatible) under the settings for the app (if
> > > > they exist) ...
> > > >    2. ... script in a fix so that it does this in your login shell
> > > > [you shouldn't use xterm systemwide for your TERM var, especially if
> > > > you login remotely via SSH and use CLI programs like pine (pine's
> > > > stupid and doesn't know how to emulate the xterm terminal properly
> > > > without hacking the source IIRC)] ...
> > >
> > > 	Ok, I have TERM Set everywhere, plus in ~./zlogin, I have stty
> > > 	set things  correctly, so it must be 3.
> > >
> > > >    3. ... fix the keyboard layout ...
> > >
> > > 	Problem here is HOW?  Many months ago my daughter spilled a
> > > 	glass of water on my working IBM keyboard.  Surprise, the
> > > 	water washed away the rinted leads... . (*mumble*) Since I
> > > 	have a few others, (old, without the M$ cr*ap keys), I
> > > 	chose the best, least sticky keyboard and used it.
> > >
> > > 	I remapped my ~/.xmodmaprc file {{ "temporarily", ha, ha }}.
> > > 	How else do I fix the layout?   IIRC, there was some place
> > > 	to set the keyboard: 101, 104, 105, &c.  This old one is
> > > 	probably a 101-key model.  It's a no-name deal.
> > >
> > > 	Clues please?
> > >
> > > 	gary
> > >
> > >
> > > 	PS: {{ WARNING}}: I'Ve got a beg-athon posting upcooming....
> > >
> > > > ... '^?' will be replaced with backspaces. 3. is the best solution,
> > > > but I had to do 1. before, because I didn't have root access on the
> > > > servers.
> >
> > Gosh, I had this on BSDi terminals for ages and had something in my
> > .*_profile to fix it. I think it was stty erase ^H where ^H was typed by
> > ctrl+v followed by 'H'. Should be able to execute that on terminal open
> > vim and test it.
>
> 	In in ~/.zlogin (on all 5 machines) I've got
>
> 	eval `tset -e^H -i^C -s -Q -m 'dialup:?xterm'`;
>
> 	That  did the job until recently.   Somewhere in deep memory I
> 	remember the ^V^H stuff.  Wasn't the '^' + 'H' ??

Maybe. I can't recall. Btw, you set erase to backspace there, but get a delete 
sequence, so maybe deleting -e^H on the target machine works. Then again, vim 
may be using erase2, rather then erase. Look at stty control characters 
section and fiddle around, then stick with what works. That's usually the 
best option for this non-printing character stuff :p

> 	I think Garrett had the right solution, tho.

Yeah, if the terminal definition is correct on the target machine, which isn't 
always the case.

-- 
Mel