Re: Backspace in python3.13 after reset

Greg Troxel <[email protected]> Tue, 04 Aug 2026 13:22:43 -0400
Newsgroups gmane.os.netbsd.general
Message-ID <[email protected]>
Joel <[email protected]> writes:

> If I ssh into my NetBSD device and run python3.13 and hit backspace,
> it works as expected. Cool. If I exit() python3.13 and run reset, then
> run python3.13 and hit backspace, it doesn't work.

There are a lot of assumptions buried in there.

Basically, there are two schools of thought, about the use of ASCII
codepoints BS and DEL for terminal input on Unix:

  1. DEL is what you type to delete the last character typed.  These
  days, the OS sends BS SPC BS to show you that.  Long ago, it printed
  /c/ to delete a c on an ASR-33, or something, now paged out.  BS is
  not a key you use and ^H is what you type in emacs to get help.  I
  associate this with east-coast DEC culture.

  2. BS is what you type to delete the last character typed.   I don't
  related to this tribe :-)


The choice flows through to

  - How do you set up the key in the upper R of PC keyboard:  does it
    send send DEL or BS?

  - How do you configure the tty?  ("stty erase" in particular)

  - Do you have ssh/telnet/etc. set up so that these settings are
    propagated?

  - what does your shell do, and other programs, if they are doing their
    own processing, vs OS line mode?


This should be enough of a hint to dig in.   Start by 'stty erase' at
where you type and figure out the keys, and perhaps also xev.   Then see
if ssh to remote system propagates the erase character.  and if python
respects it.   Run "stty -a" before and after reset, and diff them.
Then you should be enlightened and if not ask again!