git.scottworley.com Git - keystroke-timestamps/blob - keystroke-timestamps.c

   1 #include <err.h>
   2 #include <fcntl.h>
   3 #include <getopt.h>
   4 #include <linux/input.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <sysexits.h>
   9 #include <sys/select.h>
  10 #include <unistd.h>
  11
  12 int main (int argc, char **argv)
  13 {
  14   int print_usec = 0;
  15   char* device = strdup("/dev/input/by-path/platform-i8042-serio-0-event-kbd");
  16   struct option long_options[] = {
  17     {"device", required_argument, 0,            'd' },
  18     {"usec",   no_argument,       &print_usec,  1   },
  19     {0,        0,                 0,            0   },
  20   };
  21   while (1) {
  22     int c = getopt_long(argc, argv, "", long_options, NULL);
  23     if (c == -1) break;
  24     if (c == 'd') {
  25       free(device);
  26       device = strdup(optarg);
  27       continue;
  28     }
  29     if (c != 0) exit(EX_USAGE);
  30   }
  31
  32   int open_fd = open(device, O_RDONLY);
  33   if (open_fd < 0) {
  34     err(EX_NOINPUT, "Could not open keyboard event file");
  35   }
  36   int maxfd = open_fd;
  37   free(device);
  38   struct input_event i;
  39   fd_set all_inputs, ready_inputs;
  40   FD_ZERO(&all_inputs);
  41   FD_SET(open_fd, &all_inputs);
  42   while (1) {
  43     ready_inputs = all_inputs;
  44     if (select(maxfd+1, &ready_inputs, NULL, NULL, NULL) != 1) {
  45       err(EX_IOERR, "select");
  46     }
  47     for (int fd=0; fd <= maxfd; fd++) {
  48       if (FD_ISSET(fd, &ready_inputs)) {
  49         int read_return = read(fd, &i, sizeof(i));
  50         if (read_return == -1) {
  51           err(EX_IOERR, "read");
  52         }
  53         if (read_return != sizeof(i)) {
  54           errx(EX_IOERR, "Unexpected EOF");
  55         }
  56         if (i.type == 1 && i.value == 1) {
  57           if (print_usec) {
  58             printf("%ld.%06ld\n", i.time.tv_sec, i.time.tv_usec);
  59           } else {
  60             printf("%ld\n", i.time.tv_sec);
  61           }
  62           fflush(stdout);
  63         }
  64       }
  65     }
  66   }
  67   return 0;
  68 }