Re: Ctrl-[ ?

[Jean-Christophe Helary]

> On Jun 6, 2019, at 22:42, tomas@tuxteam.de wrote:
> 
> On Thu, Jun 06, 2019 at 01:49:19PM +0900, Jean-Christophe Helary wrote:
>> I'm finding that Ctrl-[ is associated to Esc but I have nothing like this in 
>> my init file.
>> 
>> Hitting Ctrl-[ in C-h k also gives Esc.
>> 
>> Why is that ?
> 
> If you have a decent computer (and OS): go open a terminal and type
> in "man ascii". You'll see two colums: those less than 64 (i.e.
> characters with the second bit set to zero) and those 64 and beyond.
> 
> CTRL traditionally makes those "characters" normally non accessible
> (because they aren't real characters) accessible by suppressing that
> second bit: look to the right column.
> 
> Thus, CTRL-@ -> NULL, CTRL-A -> SOH, etc. (notably, CTRL-G is a bell,
> CTRL-C is ETX (end of text), CTRL-D EOT (end of transmission). You
> might recognize some conventions coming from that.
> 
> If you go down that two parallel columns, you'll see that ESC is
> paired with CTRL-[
> 
> It's in your computer's reptile brain, not always visible, but
> lurking :-)

That explains something (thank you) but not why emacs needs to stick to that.


Jean-Christophe Helary
-----------------------------------------------
http://mac4translators.blogspot.com @brandelune