OT: how to tell when i've hit a Fn key?

Polytropon freebsd at edvax.de
Fri Oct 7 07:56:22 UTC 2011

On Fri, 7 Oct 2011 02:36:49 -0500 (CDT), Robert Bonomi wrote:
> > Date: Fri, 7 Oct 2011 09:18:57 +0200
> > From: Polytropon <freebsd at edvax.de>
> > Cc: FreeBSD Mailing List <freebsd-questions at freebsd.org>
> > Subject: Re: OT: how to tell when i've hit a Fn key?
> >
> > On Thu, 6 Oct 2011 15:41:17 -0700, Gary Kline wrote:
> > > 
> > > I've got a 103-key keyboard.  most  of them produce the right WAV
> > > file.  i was having some trouble with the arrow key, but think i've
> > > found a resolution.  next are the Function key, F1 to F12. 
> > > 
> > > anybody on-list familiar with curses and can help me  with this?
> > > right now, most of the function keys output 4 clicks [!].  
> >
> > Capturing PF keys is very easy with ncurses.
> > The macro KEY_F(n), n=1..12, can be checked
> > as the result of the getch() function. The
> > other "special keys" also have such macros
> > assigned. You can find them in the header
> > file /usr/local/include/ncurses/ncurses.h
> > around line 1400.
> No need to go chasing that far. 
>    #include <ncurses.h>
> pulls in the macro definitions as well.

That's what I wanted to suggest. :-)
The NCurses function getch() deals well with the
key macros defined here, so no need to deal with
the zero-byte manually.

> KEY_F(n) supports 'n' values in the range from 0 to 64.  
> value of this macro is a range of 64 consecutive values, starting with
> KEY_F0 -- which is defined as *octal* 0410
> it may take a little experimenting to see which key (plus modifier key(s)
> like 'shift','control', etc, map to which 'n' values)

The port misc/kbdscan can be used to obtain keyboard
information; however: "Please note that this program
will only work in the FreeBSD console", but it works
perfectly in the FreeBSD console (text mode); after
a certain time-out, the program automatically quits
as it will capture _all_ keys like Alt+F(n), ^C and
the like. Sadly, there is no manpage that states this
simple fact. :-(

In most cases, KEY_F(1) - KEY_F(12) will map to the
physical F1 to F12 keys, KEY_F(13) - KEY_F(24) to
the Shift+F1 to Shift+F12 keys; this mechanism has been
the default idea of providing 24 function keys to keyboards
that only offer 12 of them. But as many things that have
proven to work flawlessly, this might have changed into
something broken, erm "more modern"...

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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