Re: Available keys. Was: Re: [Nano-devel] Re: A suggestion - set and goto mark

[David Lawrence Ramsey]

John M. Gabriele wrote:

<snip>

> Is there a shortage of available keys? Looking at the main help screen
> using nano 1.3.11, it looks like the following keys are not bound to
> anything:

See below.  Note that I'm assuming you're using current CVS and not
1.3.11.

> (My notes on what the key seems to actually do comes after the two
> dashes.)
>
> Control keys:
>
> ^q -- displays: [ XON ignored, mumble mumble. ]
> ^s -- displays: [ XOFF ignored, mumble mumble. ]
> ^z

^Z is used for suspending nano, if the -z option is used (as Jordi
already mentioned).

> ^1 -- just prints a 1
> ^2 -- moves down by paragraph?

^2 is equivalent to ^Space.

> ^3

^3 is equivalent to Escape.

> ^4 -- search replace?
> ^5

^5 is equivalent to ^].

> ^7 -- go to line?
> ^8 -- backspace?

^8 can also be Delete, if the -d option is used.

> ^9 -- just prints 9
> ^0 -- just prints 0
> ^' -- just prints a '

These three aren't valid control keys.

> ^` -- down by paragraph?

Equivalent to ^Space.

> ^; -- just prints a ;

This isn't a valid control key.

> ^/ -- go to line #, col #?
> ^[ -- I think this is supposed to be the same as ESC. (nothing to do
> with nano)

Exactly.  ^[ is equivalent to Escape.

> ^]

This has to be ignored, because it's the escape character under telnet.

> ^= -- just prints an =

This isn't a valid control key.

> And Meta (Alt) keys (these just print the plain char unless
> othewise noted):
>
> M-e
> M-u

Reserved for Undo and Redo.

> M-1
> M-2
> M-3
> M-4
> M-5

These five are currently unused.

> M-6

An alias for M-^, used for copying text, in the same way ^K is used for
cutting it.

> M-7
> M-8
> M-'
> M-`
> M-;

These five are currently unused.

> M-/

This moves to the last line of the file.

> M-\

This moves to the first line of the file.

> M-[ -- takes a while, but eventually inserts a [

That's because many escape sequences start with ^[ [, and the delay is
needed to check for them.  This is why it's not used as an alias for
M-}.

> Are all these keys (except ^[, I suppose) available? If not, what are
> they being used for?

See above.

> (BTW, I'm on an xterm with "xterm*metaSendsEscape: true".)

Among the 127 ASCII characters, all valid control keys from ASCII 0 to
ASCII 31 (and all of their standard aliases that I know of) are as
follows:

Ctrl-Space is ASCII 0
Ctrl-/ is ASCII 31
Ctrl-3 to Ctrl-7 are ASCII 27 to ASCII 31
Ctrl-8 is ASCII 127
Ctrl-@ to Ctrl-_ are ASCII 0 to ASCII 31
Ctrl-` to Ctrl-~ are ASCII 0 to ASCII 31
Ctrl-? is ASCII 127
Tab is ASCII 9
Enter is ASCII 13
Escape is ASCII 27
Backspace is ASCII 127 sometimes
Delete is ASCII 127 sometimes