Terminal setting "Escape non-ASCII" as "Enable non-ASCII"?

I learnt that one of the Terminal window settings, under "emulation"
and on by default in current Panther Terminal, sends outside-ASCII
characters as combinations of ^V and some other character. In the
..plist file the <key> is something like UseCtrlVEscapes.

The English label for the setting is accurate: "Escape non-ASCII ...".
The Finnish confused me: it translates as "Enable non-ASCII ...", but
between the computers that I use, it disables non-ASCII, making local
and remote Bash and Emacs just beep at me; they don't seem to expect
these ^V-escapes.

Does "Enable non-ASCII ..." make sense to somebody? What programs,
protocols, systems use ^V this way? Hm, actually, why is this option
there at all, and why is it on by default?

 

I'm not sure why it's not working for you in bash, but in Emacs, the way
to enter control characters literally is by preceding them with
Control-q. Control-v is used in most other environments, including bash
(unless you've customized this away).

It's the default "lnext" (literal next) character in the terminal driver.

 

I know how to use ^Q in Emacs and ^V in Bash this way. Mostly I use
them to enter a literal TAB or NL. These are ASCII characters.

I see now that I omitted important information. The characters that
the setting broke here are letters in the upper side of Latin-1. Not
control characters, and not ASCII. I have keys in the keyboard to
produce them.

Bash does not beep when the escape is on, I was wrong about that
above, but it accepts these letters either way. With escapes off, when
I press "^Vö", Bash receives the single letter "ö" literally; with
escapes on, when I press "^Vö", it receives the two characters "^Vö",
which is not what I meant.

I see now why Emacs beeped at "^Vö": I was testing in an empty buffer,
so it couldn't scroll. When the buffer has text, it first scrolls and
then inserts the letter. Not what I meant, but now I see what's going
on.

The fact remains that my non-ASCII characters work when I do not
"ebable" them and stop working when I do, which is funny.

Is the terminal supposed to reject non-ASCII characters without this
escape? I understand about control characters. I'm not quite sure what
a terminal or a terminal driver is, as opposed to a shell like Bash.

Thank you.

 

The only characters that are normally accepted literally on a terminal
are ASCII graphic characters. Some control characters have special
meanings, either assigned by the operating system (you can see these
with "stty -a") or by certain applications like bash. Anything else is
rejected.