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Re: Convert input to upper case on screen as it is typed

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Ben Finney <ben+python@benfinney.id.au> writes:

> Ben Finney <ben+python@benfinney.id.au> writes:
>
> > Okay, ‘termios.tcgetattr’ will let me preserve the attributes, and
> > with Dan Sommers's suggestion of which attribute to use, I may have
> > a shot at setting the terminal attributes.
>
> This works!

Except, it doesn't. As designed and documented in the Single Unix
Specification <URL:http://pubs.opengroup.org/onlinepubs/7908799/>,
the behaviour of the OLCUC feature is:

    OLCUC     Map lower case to upper on output. (LEGACY)

    <URL:http://pubs.opengroup.org/onlinepubs/7908799/xbd/termios.html>

That ominous “LEGACY” annotation is applied, notably, to all the
case-conversion features of ‘termios’.

The mapping is ignorant of Unicode, ignorant of ANSI escape sequences;
it blindly converts bytes via a mapping that assumes all bytes are ASCII
text, regardless of whether those bytes actually represent text.

It breaks the “visual bell” feature, among others. I end up with garbage
on the screen, that would otherwise have been Unicode text or useful
control sequences.

> I had been hoping that I could simply wrap some stream in a simple
> “convert what they actually type so it's upper case” text codec,
> without fiddling at such a low operating-system specific level. This
> is rather more esoteric than I had hoped.

And, it turns out, doesn't address the requirements without causing more
problems.

I am still looking for a solution (a Python-specific one would be fine).

-- 
 \           “Anything that we scientists can do to weaken the hold of |
  `\        religion should be done and may in the end be our greatest |
_o__)                  contribution to civilization.” —Steven Weinberg |
Ben Finney

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Thread

Convert input to upper case on screen as it is typed Ben Finney <ben+python@benfinney.id.au> - 2016-04-14 13:25 +1000
  Re: Convert input to upper case on screen as it is typed Dan Sommers <dan@tombstonezero.net> - 2016-04-14 04:16 +0000
    Re: Convert input to upper case on screen as it is typed Ben Finney <ben+python@benfinney.id.au> - 2016-04-14 15:17 +1000
      Re: Convert input to upper case on screen as it is typed Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-04-14 18:35 +1200
    Re: Convert input to upper case on screen as it is typed Ben Finney <ben+python@benfinney.id.au> - 2016-04-14 17:53 +1000
      Re: Convert input to upper case on screen as it is typed Steven D'Aprano <steve@pearwood.info> - 2016-04-14 21:43 +1000
    Re: Convert input to upper case on screen as it is typed Ben Finney <ben+python@benfinney.id.au> - 2016-04-14 18:37 +1000
      Re: Convert input to upper case on screen as it is typed Marko Rauhamaa <marko@pacujo.net> - 2016-04-14 12:22 +0300
    Re: Convert input to upper case on screen as it is typed Chris Angelico <rosuav@gmail.com> - 2016-04-14 18:45 +1000
    Re: Convert input to upper case on screen as it is typed Ben Finney <ben+python@benfinney.id.au> - 2016-04-19 05:11 +1000
      Re: Convert input to upper case on screen as it is typed Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-04-19 17:46 +1200

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