ref: 9ca327dd06c30341d984bff84727ea451b428db7
dir: /man/10/kbdputc/
.TH KBDPUTC 10.2
.SH NAME
kbdputc, kbdrepeat, kbdclock, kbdq \- keyboard interface to \fIcons\fP(3)
.SH SYNOPSIS
.ta \w'\f5extern\ \ \f1'u
.B
#include "keyboard.h"
.PP
.B
void kbdputc(Queue *q, int c)
.PP
.B
void kbdrepeat(int on)
.PP
.B
void kbdclock(void)
.PP
.B
extern Queue *kbdq;
.SH DESCRIPTION
This is the internal interface between
.B /dev/keyboard
of
.IR cons (3)
and the architecture-dependent keyboard driver.
Before calling any of these functions,
the global variable
.B kbdq
must be initialised;
.IR cons (3)
does not initialise it.
This is usually done during system initialisation by the keyboard driver's
.I kbdinit
function ,
as follows:
.IP
.EX
kbdq = qopen(4*1024, 0, 0, 0);
qnoblock(kbdq, 1);
.EE
.PP
.I Kbdputc
puts a 16-bit Unicode character
.I c
(ie, a `rune')
on the given
.IR q ,
as a sequence of bytes in UTF-8 encoding
(see
.IR utf (6)).
If
.I c
is the special value
.B Latin
(defined by
.BR keyboard.h ),
.I kbdputc
starts collecting characters, looking for the typeable representations of
Unicode characters defined by
.IR keyboard (6);
at the end of a complete such sequence,
.I kbdputc
queues the UTF-8 encoding of the corresponding Unicode character.
It is up to the keyboard driver to map a suitable physical keyboard character
(or combination of characters) to the code
.BR Latin .
.PP
Drivers that need to implement repeat of keypresses in software
should call
.IP
.EX
addclock0link(kbdclock);
.EE
.PP
at the end of
.IR kbdinit ,
to cause
.I kbdclock
to be called each clock tick.
.I Kbdrepeat
can then be called to enable
.RI ( on
is non-zero)
or disable it
.RI ( on
is zero).
When repeat is on,
.I kbdclock
(when called) will periodically call
.BI "kbdputc(" kbdq , c )
where
.I c
is the last rune given to
.IR kbdputc .
The driver is responsible for enabling and disabling repeat appropriately;
for instance, function keys and certainly
.B Latin
should typically not be repeated.
.SH SOURCE
.B /os/*/kbd*.c
.SH SEE ALSO
.IR cons (3),
.IR utf (6),
.IR qio (10.2)