Golang Kqueue Snippet

gistfile1.go

// helpful links:
// https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man2/EV_SET.2.html
// http://julipedia.meroh.net/2004/10/example-of-kqueue.html

// create kqueue
kq, err := syscall.Kqueue()
if err != nil {
	log.Println("Error creating Kqueue descriptor!")
	return
}
// open folder
fd, err := syscall.Open("/home/test", syscall.O_RDONLY, 0)
if err != nil {
	log.Println("Error opening folder descriptor!")
	return
}
// build kevent
ev1 := syscall.Kevent_t{
	Ident:  uint64(fd),
	Filter: syscall.EVFILT_VNODE,
	Flags:  syscall.EV_ADD | syscall.EV_ENABLE | syscall.EV_ONESHOT,
	Fflags: syscall.NOTE_DELETE | syscall.NOTE_WRITE,
	Data:   0,
	Udata:  nil,
}
// configure timeout
timeout := syscall.Timespec{
	Sec:  0,
	Nsec: 0,
}
// wait for events
for {
	// create kevent
	events := make([]syscall.Kevent_t, 10)
	nev, err := syscall.Kevent(kq, []syscall.Kevent_t{ev1}, events, &timeout)
	if err != nil {
		log.Println("Error creating kevent")
	}
	// check if there was an event
	for i := 0; i < nev; i++ {
		// log
		log.Printf("Event [%d] -> %+v", i, events[i])
	}
}