gistfile1.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

int main(int argc, char **argv)
{
  int fd;
  if(argc < 2) {
    printf("usage: %s <device>\n", argv[0]);
    return 1;
  }
  fd = open(argv[1], O_RDONLY);
  struct input_event ev;

  while (1)
  {
    read(fd, &ev, sizeof(struct input_event));

    if(ev.type == 1)
      printf("key %i state %i\n", ev.code, ev.value);

  }
}

struct input_event {
  struct timeval time;
  __u16 type;
  __u16 code;
  __s32 value;
};

/********************************************
 * Dies with:

/tmp/cap.c: In function ‘main’:
/tmp/cap.c:16: error: storage size of ‘ev’ isn’t known
/tmp/cap.c:20: error: invalid application of ‘sizeof’ to incomplete type ‘struct input_event’ 
/tmp/cap.c: At top level:
/tmp/cap.c:30: error: expected specifier-qualifier-list before ‘__u16’

**********************************************/