Clive, 2nd ed. User's manual. Section 2 
SYNOPSYS

import "clive/fswatch"

func New() (*Watcher, error)
type Watcher struct { ... }
    func New() (*Watcher, error)

DESCRIPTION

file system watcher

CONSTANTS

TYPES

type Watcher struct {
	// contains filtered or unexported fields
}
    Watcher for file system changes (unix; not ZX)

func New() (*Watcher, error)
    Create a new watcher

func (w *Watcher) Add(p string) error
    Add a file to the watcher list. Must be called before watching changes. If
    the file is a directory all the files in it are also watched (w/o recur. for
    subdirs)

func (w *Watcher) Changes() chan string
    Report changes through the returned chan.

func (w *Watcher) Once()
    Arrange for w to be done after the first change reported.

FUNCTIONS

User's manual, 2nd ed. Section 2