kevent

#include <stdio.h>
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>

int main()
{
  int kq;
  int n;
  struct kevent event[1];
  struct timespec ts;
  FILE *filep;

  filep = fopen("/home/huxw/test/michael", "r");
  if (!filep) exit(1);

  ts.tv_sec = 0; //设置ts
  ts.tv_nsec = 0;

  // 做一个event.
  EV_SET( &event[0], fileno(filep), EVFILT_VNODE,
          EV_ADD,
          NOTE_DELETE | NOTE_ATTRIB | NOTE_WRITE, 0, 0);

  //产生一个queue
  if ( (kq=kqueue()) < 0) exit(2);

  //在queue中注册event
  if ( (n = kevent(kq, event, 1, NULL, 0, &ts) < 0) exit(3);

  //ts为NULL, 相当于wait吧, 要poll的话可以还用之前的ts
  n = kevent(kq, NULL, 0, event, 1, NULL);
  if ( n == 0 ) {
     printf("Nothing to do with it\n");
  } else {
    if (event->filter == EVFILT_VNODE && event->fflags == NOTE_DELETE) {
       printf("deleting...\n");
    }
    else if (event->filter == EVFILT_VNODE && event->fflags == NOTE_ATTRIB) {
       printf("attribution changed..\n");
    }
    else if (event->filter == EVFILT_VNODE && event->fflags == NOTE_WRITE) {
       printf("write to it..\n");
    }
  }
  return 0;
}