integrate inotify syscalls

internal/inotify/watcher.go

@@ -0,0 +1,25 @@
+package inotify
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/unix"
+)
+
+const events = unix.IN_ALL_EVENTS
+
+type watcher struct {
+	wd  int
+	dir string
+}
+
+func newWatcher(fd int, dir string, ping chan struct{}) (*watcher, error) {
+	wd, errno := unix.InotifyAddWatch(fd, dir, events)
+	if wd == -1 {
+		return nil, fmt.Errorf("adding watcher on %s: %d", dir, errno)
+	}
+	return &watcher{
+		wd:  wd,
+		dir: dir,
+	}, nil
+}