1 .TH KEYBOARD 3
2 .SH NAME
3 initkeyboard, ctlkeyboard, closekeyboard \- keyboard control
4 .SH SYNOPSIS
5 .nf
6 .B
7 #include <u.h>
8 .B
9 #include <libc.h>
10 .B
11 #include <thread.h>
12 .B
13 #include <keyboard.h>
14 .PP
15 .B
16 Keyboardctl	*initkeyboard(char *file)
17 .PP
18 .B
19 int			ctlkeyboard(Keyboardctl *kc, char *msg)
20 .PP
21 .B
22 void			closekeyboard(Keyboard *kc)
23 .SH DESCRIPTION
24 These functions access and control a keyboard interface
25 for character-at-a-time I/O in a multi-threaded environment, usually in combination with
26 .IR mouse (3).
27 They use the message-passing
28 .B Channel
29 interface in the threads library
30 (see
31 .IR thread (3));
32 programs that wish a more event-driven, single-threaded approach should use
33 .IR event (3).
34 .PP
35 .I Initkeyboard
36 opens a connection to the keyboard and returns a
37 .B Keyboardctl
38 structure:
39 .IP
40 .EX
41 .ta 6n +\w'Channel 'u +\w'consfd;   'u
42 typedef struct Keyboardct Keyboardctl;
43 struct Keyboardctl
44 {
45 	Channel	*c;	/* chan(Rune[20]) */
46 
47 	char	*file;
48 	int	consfd;		/* to cons file */
49 	int	ctlfd;		/* to ctl file */
50 	int	pid;		/* of slave proc */
51 };
52 .EE
53 .PP
54 The argument to
55 .I initkeyboard
56 is a
57 .I file
58 naming the device file from which characters may be read,
59 typically
60 .BR /dev/cons .
61 If
62 .I file
63 is nil,
64 .B /dev/cons
65 is assumed.
66 .PP
67 Once the
68 .B Keyboardctl
69 is set up a
70 message containing a
71 .BR Rune
72 will be sent on the
73 .B Channel
74 .B Keyboardctl.c
75 to report each character read from the device.
76 .PP
77 .I Ctlkeyboard
78 is used to set the state of the interface, typically to turn raw mode on and off
79 (see
80 .IR cons (3)).
81 It writes the string
82 .I msg
83 to the control file associated with the device, which is assumed to be the regular device file name
84 with the string
85 .B ctl
86 appended.
87 .PP
88 .I Closekeyboard
89 closes the file descriptors associated with the keyboard, kills the slave processes,
90 and frees the
91 .B Keyboardctl
92 structure.
93 .PP
94 .SH SOURCE
95 .B /usr/local/plan9/src/libdraw
96 .SH SEE ALSO
97 .IR graphics (3),
98 .IR draw (3),
99 .IR event (3),
100 .IR thread (3).
101 .SH BUGS
102 Because the interface delivers complete runes,
103 there is no way to report lesser actions such as
104 shift keys or even individual bytes.