1 /* vi: set sw=4 ts=4: */
2 /*
3 * shows keys pressed. inspired by kbd package
4 *
5 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
6 *
7 * Licensed under GPLv2, see file LICENSE in this source tree.
8 */
9 //config:config SHOWKEY
10 //config: bool "showkey (4.7 kb)"
11 //config: default y
12 //config: help
13 //config: Shows keys pressed.
14
15 //applet:IF_SHOWKEY(APPLET(showkey, BB_DIR_USR_BIN, BB_SUID_DROP))
16
17 //kbuild:lib-$(CONFIG_SHOWKEY) += showkey.o
18
19 //usage:#define showkey_trivial_usage
20 //usage: "[-a | -k | -s]"
21 //usage:#define showkey_full_usage "\n\n"
22 //usage: "Show keys pressed\n"
23 //usage: "\n -a Display decimal/octal/hex values of the keys"
24 //usage: "\n -k Display interpreted keycodes (default)"
25 //usage: "\n -s Display raw scan-codes"
26
27 #include "libbb.h"
28 #include <linux/kd.h>
29
30
31 struct globals {
32 int kbmode;
33 struct termios tio, tio0;
34 };
35 #define G (*ptr_to_globals)
36 #define kbmode (G.kbmode)
37 #define tio (G.tio)
38 #define tio0 (G.tio0)
39 #define INIT_G() do { \
40 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
41 } while (0)
42
43
44 // set raw tty mode
45 // also used by microcom
46 // libbb candidates?
xget1(struct termios * t,struct termios * oldt)47 static void xget1(struct termios *t, struct termios *oldt)
48 {
49 tcgetattr(STDIN_FILENO, oldt);
50 *t = *oldt;
51 cfmakeraw(t);
52 }
53
xset1(struct termios * t)54 static void xset1(struct termios *t)
55 {
56 int ret = tcsetattr(STDIN_FILENO, TCSAFLUSH, t);
57 if (ret) {
58 bb_simple_perror_msg("can't tcsetattr for stdin");
59 }
60 }
61
62 int showkey_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
showkey_main(int argc UNUSED_PARAM,char ** argv)63 int showkey_main(int argc UNUSED_PARAM, char **argv)
64 {
65 enum {
66 OPT_a = (1<<0), // display the decimal/octal/hex values of the keys
67 OPT_k = (1<<1), // display only the interpreted keycodes (default)
68 OPT_s = (1<<2), // display only the raw scan-codes
69 };
70
71 INIT_G();
72
73 // FIXME: aks are all mutually exclusive
74 getopt32(argv, "aks");
75
76 // prepare for raw mode
77 xget1(&tio, &tio0);
78 // put stdin in raw mode
79 xset1(&tio);
80
81 #define press_keys "Press any keys, program terminates %s:\r\n\n"
82
83 if (option_mask32 & OPT_a) {
84 // just read stdin char by char
85 unsigned char c;
86
87 printf(press_keys, "on EOF (ctrl-D)");
88
89 // read and show byte values
90 while (1 == read(STDIN_FILENO, &c, 1)) {
91 printf("%3u 0%03o 0x%02x\r\n", c, c, c);
92 if (04 /*CTRL-D*/ == c)
93 break;
94 }
95 } else {
96 // we assume a PC keyboard
97 xioctl(STDIN_FILENO, KDGKBMODE, &kbmode);
98 printf("Keyboard mode was %s.\r\n\n",
99 kbmode == K_RAW ? "RAW" :
100 (kbmode == K_XLATE ? "XLATE" :
101 (kbmode == K_MEDIUMRAW ? "MEDIUMRAW" :
102 (kbmode == K_UNICODE ? "UNICODE" : "UNKNOWN")))
103 );
104
105 // set raw keyboard mode
106 xioctl(STDIN_FILENO, KDSKBMODE, (void *)(ptrdiff_t)((option_mask32 & OPT_k) ? K_MEDIUMRAW : K_RAW));
107
108 // we should exit on any signal; signals should interrupt read
109 bb_signals_norestart(BB_FATAL_SIGS, record_signo);
110
111 // inform user that program ends after time of inactivity
112 printf(press_keys, "10s after last keypress");
113
114 // read and show scancodes
115 while (!bb_got_signal) {
116 char buf[18];
117 int i, n;
118
119 // setup 10s watchdog
120 alarm(10);
121
122 // read scancodes
123 n = read(STDIN_FILENO, buf, sizeof(buf));
124 i = 0;
125 while (i < n) {
126 if (option_mask32 & OPT_s) {
127 // show raw scancodes
128 printf("0x%02x ", buf[i++]);
129 } else {
130 // show interpreted scancodes (default)
131 char c = buf[i];
132 int kc;
133 if (i+2 < n
134 && (c & 0x7f) == 0
135 && (buf[i+1] & 0x80) != 0
136 && (buf[i+2] & 0x80) != 0
137 ) {
138 kc = ((buf[i+1] & 0x7f) << 7) | (buf[i+2] & 0x7f);
139 i += 3;
140 } else {
141 kc = (c & 0x7f);
142 i++;
143 }
144 printf("keycode %3u %s", kc, (c & 0x80) ? "release" : "press");
145 }
146 }
147 puts("\r");
148 }
149
150 // restore keyboard mode
151 xioctl(STDIN_FILENO, KDSKBMODE, (void *)(ptrdiff_t)kbmode);
152 }
153
154 // restore console settings
155 xset1(&tio0);
156
157 return EXIT_SUCCESS;
158 }
159