1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
/*
xkbcat
------
Monitors key presses globally across X11.
*/
#include <X11/Xlib.h>
#include <X11/X.h>
#include <X11/XKBlib.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <time.h>
char * DEFAULT_DISPLAY = ":0";
const int DEFAULT_DELAY = 10000000;
const bool DEFAULT_PRINT_UP = false;
typedef char KbBuffer[32];
static inline bool keyState(KbBuffer c, int key) {
return ( c[key/8] & (1<<(key%8)) );
}
char * keyPressToString(Display * disp, int code, bool down);
int printUsage() {
printf("\
USAGE: xkbcat [-display <display>] [-delay <nanosec>] [-up]\n\
display target X display (default %s)\n\
delay polling frequency; nanoseconds (default %d)\n\
up also print key-ups (default %s)\n",
DEFAULT_DISPLAY, DEFAULT_DELAY, (DEFAULT_PRINT_UP ? "yes" : "no") );
exit(0);
}
int main(int argc, char * argv[]) {
char * hostname = DEFAULT_DISPLAY;
int delay = DEFAULT_DELAY;
bool printKeyUps = DEFAULT_PRINT_UP;
// Get args
for (int i = 1; i < argc; i++) {
if (!strcmp(argv[i], "-help")) printUsage();
else if (!strcmp(argv[i], "-display")) hostname = argv[++i];
else if (!strcmp(argv[i], "-delay")) delay = atoi(argv[++i]);
else if (!strcmp(argv[i], "-up")) printKeyUps = true;
else printUsage();
}
// Setup Xwindows
Display * disp = XOpenDisplay(hostname);
if (NULL == disp) {
fprintf(stderr, "Cannot open X display: %s\n", hostname);
exit(1);
}
XSynchronize(disp, true);
// Setup buffers
KbBuffer keyBuffer1, keyBuffer2;
KbBuffer * oldKeys = &keyBuffer1,
* keys = &keyBuffer2;
XQueryKeymap(disp, * oldKeys); // Initial get
struct timespec sleepTime = { .tv_nsec = delay };
while (1) { // Forever
// Get changed keys
XQueryKeymap(disp, * keys);
for (int i = 0; i < sizeof(KbBuffer) * 8; i++) {
bool stateBefore = keyState(*oldKeys, i),
stateNow = keyState(*keys, i);
if ( stateNow != stateBefore // Changed?
&& (stateNow || printKeyUps) ) // Should print?
{
printf("%s\n", keyPressToString(disp, i, stateNow));
fflush(stdout); // Ensure pipe is updated
}
}
{ // Swap buffers
KbBuffer * temp = oldKeys;
oldKeys = keys;
keys = temp;
}
nanosleep(&sleepTime, NULL);
}
}
/*
Have a keycode, Look up keysym for it.
Convert keysym into its string representation.
Put it as (+string) or (-string), depending on if it's up or down.
Print out the string.
*/
char * keyPressToString(Display * disp, int code, bool down) {
const int KEYSYM_STRLEN = 64;
static char * str, buf[KEYSYM_STRLEN + 1];
KeySym keysym = XkbKeycodeToKeysym(disp, code, 0, 0);
if (NoSymbol == keysym) return "";
// Convert keysym to a string, copy it to a local area
str = XKeysymToString(keysym);
if (NULL == str) return "";
strncpy(buf, str, KEYSYM_STRLEN); buf[KEYSYM_STRLEN] = 0;
// Still a string, so put it in form (+str) or (-str)
if (down) strcpy(buf, "+ ");
else strcpy(buf, "- ");
strcat(buf, str);
return buf;
}
|
