linux/event.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <fcntl.h>
   6 #include <sys/ioctl.h>
   7 #include <unistd.h>
   8 #include <linux/input.h>
   9 #include <errno.h>
  10
  11 #include "event.h"
  12
  13 #define NUM_DEVS        8
  14 #define NUM_KEYS_DOWN   16
  15
  16 #define BIT(x) (keybits[(x)/sizeof(keybits[0])/8] & \
  17         (1 << ((x) & (sizeof(keybits[0])*8-1))))
  18
  19 static int event_fds[NUM_DEVS];
  20 static int event_fd_count = 0;
  21
  22 int in_event_init(void)
  23 {
  24         int i;
  25
  26         in_event_exit();
  27
  28         for (i = 0; event_fd_count < NUM_DEVS; i++)
  29         {
  30                 int u, ret, fd, keybits[KEY_MAX/sizeof(int)];
  31                 int support = 0, count = 0;
  32                 char name[64];
  33
  34                 snprintf(name, sizeof(name), "/dev/input/event%d", i);
  35                 fd = open(name, O_RDONLY|O_NONBLOCK);
  36                 if (fd == -1)
  37                         break;
  38
  39                 /* check supported events */
  40                 ret = ioctl(fd, EVIOCGBIT(0, sizeof(support)), &support);
  41                 if (ret == -1) {
  42                         printf("in_event: ioctl failed on %s\n", name);
  43                         goto skip;
  44                 }
  45
  46                 if (!(support & (1 << EV_KEY)))
  47                         goto skip;
  48
  49                 ret = ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybits)), keybits);
  50                 if (ret == -1) {
  51                         printf("in_event: ioctl failed on %s\n", name);
  52                         goto skip;
  53                 }
  54
  55                 printf("%s: %08x\n", name, support);
  56
  57                 /* check for interesting keys */
  58                 for (u = 0; u < KEY_MAX; u++) {
  59                         if (BIT(u) && u != KEY_POWER)
  60                                 count++;
  61                 }
  62
  63                 if (count == 0)
  64                         goto skip;
  65
  66                 ioctl(fd, EVIOCGNAME(sizeof(name)), name);
  67                 printf("event: %d: using \"%s\" with %d events\n",
  68                         event_fd_count, name, count);
  69                 event_fds[event_fd_count++] = fd;
  70                 continue;
  71
  72 skip:
  73                 close(fd);
  74         }
  75
  76         printf("event: %d devices found.\n", event_fd_count);
  77         return 0;
  78 }
  79
  80 void in_event_exit(void)
  81 {
  82         for (; event_fd_count > 0; event_fd_count--)
  83                 close(event_fds[event_fd_count - 1]);
  84 }
  85
  86 int in_event_update(int binds[512])
  87 {
  88         struct input_event ev[16];
  89         int d, rd, ret;
  90         int result = 0;
  91
  92         for (d = 0; d < event_fd_count; d++)
  93         {
  94                 int keybits[KEY_MAX/sizeof(int)];
  95                 int fd = event_fds[d];
  96                 int u, changed = 0;
  97
  98                 while (1) {
  99                         rd = read(fd, ev, sizeof(ev));
 100                         if (rd < (int)sizeof(ev[0])) {
 101                                 if (errno != EAGAIN)
 102                                         perror("event: read failed");
 103                                 break;
 104                         }
 105
 106                         changed = 1;
 107                 }
 108
 109                 if (!changed)
 110                         continue;
 111
 112                 ret = ioctl(fd, EVIOCGKEY(sizeof(keybits)), keybits);
 113                 if (ret == -1) {
 114                         printf("in_event: ioctl failed on %d\n", d);
 115                         continue;
 116                 }
 117
 118                 for (u = 0; u < KEY_MAX; u++) {
 119                         if (BIT(u)) {
 120                                 printf(" %d", u);
 121                                 result |= binds[u];
 122                         }
 123                 }
 124                 printf("\n");
 125         }
 126
 127         return result;
 128 }
 129
 130 int main()
 131 {
 132         in_event_init();
 133
 134         while (1) {
 135                 int b[512];
 136                 in_event_update(b);
 137                 sleep(1);
 138         }
 139
 140         return 0;
 141 }
 142