[CentOS] Backspace key is sending Delete after update to 4.4 (tcsh issue?)

Rodrigo Barbosa rodrigob at darkover.org
Mon Sep 4 00:21:34 UTC 2006

Hash: SHA1

On Sun, Sep 03, 2006 at 08:11:18AM +0800, John Summerfield wrote:
> The correct behaviour for the backspace key is to send the BS character, 
> 0x08 aka ^H.
> ^? I suspect is the DEL character, 0x7f, which is unprintable (or prints 
> as a space). I would expect the Delete key to produce a DEL character.

The correct behaviour for who ? For many platforms (Sun is the first
one that comes to memory), the correct backspace char was always

At least here, for me, DEL shows are ^[[3~ (ANSI code ?!?).

Yes, on ASCII, DEL is 7F and BS is 08. But remember the issue here are
not charsets, but console control codes, which usually are the same, but
not always.

The definition is kind of iffy, but on the console_codes manpage
it states that, for Linux BS should indeed produce ^H. But lets remember
that is Linux specific, and might not be true to many other platforms.

Things that could be affecting this:

termcap (Built on Feb 2005)
ncurses (Bult on Feb 2005)
xterm (Built on May 2006) [CentOS 4.3 maybe?]

and probably some other things I'm missing.

One thing to circunvect this problem (on xterm at least) is to add:

*xterm*backarrowKey: true

on your ~/.Xdefaults file, or one of the systemwise equivalents
(/etc/X11/Xresources). It will change the xterm behaviour to the
way it was before.

KDE terminal (konsole) will use these xterm settings without any
problems, but for gnome-terminal you might need a little something

*gnome-terminal*backarrowKey: true

And now I can name the culprid for the problem, and it is the xterm

The file:

on 4.4 has some VT100 extra lines, including these one:

! keyboard setup
*VT100*backarrowKey: false

If you remove/comment the second one, and then reload the

xrdb -remove
xrdb -load /etc/X11/Xresource

Your (xterm|konsole|gnome-terminal) will start working again as before.

Beats me why this didn't show up before, but then again, maybe it
did and I missed it.

If you only want to fix it for your user, and have no risk of it
getting screwed up on the next update, do this:

echo "*VT100*backarrowKey: true" >> ~/.Xdefaults
xrdb -merge ~/.Xdefaults

Close your terminal windows (xterm, konsole, gnome-terminal), and open
it again. The new one will have ^H as the BS character.

This e-mail is bouncing all around cause I was writing it as I tested.
I decided to leave it as such, since most people around don't understand
about X Resources, and this could provide some interesting pointers for


- -- 
Rodrigo Barbosa
"Quid quid Latine dictum sit, altum viditur"
"Be excellent to each other ..." - Bill & Ted (Wyld Stallyns)

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