Re: translating numpad keys in linux terminal

[Dan Espen <despen@verizon.net>]

Tim Johnson <tim@akwebsoft.com> writes:

> * Emanuel Berg <embe8573@student.uu.se> [150402 17:49]:
>> Dan Espen <despen@verizon.net> writes:
>> 
>> >> Perhaps someone in this list that is familiar with
>> >> just exactly what the '-nw' option does can
>> >> enlighten us?
>> >
>> > From the docs:
>> >
>> > Don't communicate directly with the window system,
>> > disregarding the DISPLAY environment variable even
>> > if it is set. This means that Emacs uses the
>> > terminal from which it was launched for all its
>> > display and input.
>> >
>> > The terminal gets and sends X Events.
>> >
>> > Emacs gets and sends _characters_ to and from
>> > the terminal.
>> >
>> > Sometimes Emacs may get signals from the terminal,
>> > like when the terminal is resized.
>> >
>> > Emacs in a terminal does not see X Events.
>> >
>> > So, your issue is what does the terminal send to Emacs
>> > when you hit a KP key,
>> >
>> > Terminals like rxvt and xterm give you
>> > complete control.
>> >
>> > gnome-terminal, sorry, I don't use it.
>> 
>> Case closed.
>   Indeed. 
>   
>   My workstation is a Mac Mini. To recap, I get unique translations
>   of numeric keypad input to 'emacs' running from iTerm2.
>
>   I didn't get the same uniqueness when I booted the same machine
>   into ubuntu 14.04 and ran 'emacs -nw' from gnome-terminal.
>
>   The terminal emulator controls what emacs gets when it is in
>   terminal - this from the good people who responded to my
>   inquiries.
>
>   As has been pointed out, rxvt _does_ translate numeric keypad
>   uniquely (unlink gnome-terminal). By starting rxvt in my setup and
>   then invoking emacs -nw and then running <help>-c, I can see that
>   M-O sequences are being generated (that is Alt-Shift-(the capital
>   letter "O")).

The man pages describes more.
This is from an xresource file for XTerm:

XTerm*VT100.translations:#override\n\
	Shift<Key>KP_9:	scroll-back(1, page)\n\
	Shift<Key>KP_3:	scroll-forw(1, page)

The "translations" resource lets you specify
the X event and the corresponding action for that event.

So, if I wanted the un-shifted KP_9 key to
do something special I could specify:

	None<Key>KP_9:	string("Hi Mom!") \n\

The first part is the X event, the second part is the action
as described in the man page.

I'm guessing gnome-terminal has something equivalent
but perhaps not as flexible.

-- 
Dan Espen