Re: What's the meaning of "^A" in emacs?

[Marcin Borkowski]

On 2015-07-29, at 16:55, Jorge A. Alfaro-Murillo 
<jorge.alfaro-murillo@yale.edu> wrote:

> Emanuel Berg writes:
>
>> Navy Cheng <navych@126.com> writes: 
>> 
>>> What't the meaning of "^-characters" such as ^A, ^_, ^O ? I see 
>>> this characters in some files. And How can I input this 
>>> characters? Thanks. 
>> 
>> When you say "input", do you mean to *insert* them as chars into 
>> a buffer? If so, just hit C-q first.  But I don't think you 
>> should do this too often (?).
>
> Yes, why would someone use this? The only thing that I use is the 
> "form feed" (^L) to divide sections in plain text documents and 
> then be able to use C-x [ and C-x ] to move between pages.
>
> Does someone know of any other "control character" use?

Contrived, maybe, but legit.  In (La)TeX you sometimes need a character
you know for sure won't be used anywhere else (at least in a normal
document).  I know at least one LaTeX package which uses ^A, and I used
it myself when implementing a verbatim-like construct as a sort of
"escape" (more precisely, a way to insert a LaTeX command in a place
where most special characters were not special anymore).

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University