NAME

initkeyboard, ctlkeyboard, closekeyboard − keyboard control

SYNOPSIS

#include <u.h>
#include <libc.h>
#include <thread.h>
#include <keyboard.h>

Keyboardctl∗initkeyboard(char ∗file)

intctlkeyboard(Keyboardctl ∗kc, char ∗msg)

voidclosekeyboard(Keyboard ∗kc)

DESCRIPTION

These functions access and control a keyboard interface for character-at-a-time I/O in a multi-threaded environment, usually in combination with mouse(2). They use the message-passing ­Channel interface in the threads library (see thread(2)); programs that wish a more event-driven, single-threaded approach should use event(2).

­Initkeyboard opens a connection to the keyboard and returns a ­Keyboardctl structure:

typedef struct Keyboardct Keyboardctl;
struct Keyboardctl
{
Channel∗c; /∗ chan(Rune[20]) ∗/
 char∗file;
intconsfd; /∗ to cons file ∗/
intctlfd;/∗ to ctl file ∗/
intpid;/∗ of slave proc ∗/
};

The argument to ­initkeyboard is a ­file naming the device file from which characters may be read, typically /dev/cons.  If ­file is nil, ­/dev/cons is assumed. 

Once the ­Keyboardctl is set up a message containing a Rune will be sent on the ­Channel ­Keyboardctl.c to report each character read from the device. 

­Ctlkeyboard is used to set the state of the interface, typically to turn raw mode on and off (see cons(3)). It writes the string ­msg to the control file associated with the device, which is assumed to be the regular device file name with the string ­ctl appended. 

­Closekeyboard closes the file descriptors associated with the keyboard, kills the slave processes, and frees the ­Keyboardctl structure. 

SOURCE

­/sys/src/libdraw

SEE ALSO

graphics(2), draw(2), event(2), thread(2).

BUGS

Because the interface delivers complete runes, there is no way to report lesser actions such as shift keys or even individual bytes. 

Plan 9  —  February 18, 2000