使用golang实现目录的监控过程

GO实现文件夹监控

收获

• 查看 watcher.go, 看出实现一个系统event的监控，代码不过 625行；
• 执行exec.Cmd(), cmd.Run()， 可以获得shell的执行状态；
• 开始阅读github上的开源代码， 代码特别精简；

说明

项目组有一个需求，即当团队人员更新Gitbook到服务器的时候，服务器的gitbook目录下需要pull操作；

通过了解，当成员提交push内容到服务器的时候， git/objects目录下内容会create, modify, access等事件；

前期通过shell+inotifywait实现，但是总存在push的时候获取不到，或者上push之后频繁更新gitbook；

本次使用 github.com/radovskyb/watcher 来使用；

其中在本地执行如下命令, 获取watcher的库；

go get github.com/radovskyb/watcher

通过范例，结合自己的脚本 pull.book.sh; 完成git book的操作；

package main

import (
	"fmt"
	"log"
	"os/exec"
	"time"

	"github.com/radovskyb/watcher"
)

func main() {
	w := watcher.New()

	// SetMaxEvents to 1 to allow at most 1 event's to be received
	// on the Event channel per watching cycle.
	//
	// If SetMaxEvents is not set, the default is to send all events.
	w.SetMaxEvents(1)

	// Only notify rename and move events.
	//  w.FilterOps(watcher.Rename, watcher.Move)
	w.FilterOps(watcher.Create, watcher.Write, watcher.Chmod)

	go func() {
		for {
			select {
			case event := <-w.Event:
				fmt.Println(event) // Print the event's info.
				c := "pull.book.sh"
				cmd := exec.Command(c, "")
				err := cmd.Run()
				fmt.Printf("Command finished with error: %v\n", err)
			case err := <-w.Error:
				log.Fatalln(err)
			case <-w.Closed:
				return
			}
		}
	}()

	// Watch this folder for changes.
	if err := w.Add("/srv/git/objects"); err != nil {
		log.Fatalln(err)
	}

	// Watch test_folder recursively for changes.
	if err := w.AddRecursive("/srv/git/objects"); err != nil {
		log.Fatalln(err)
	}

  /*
	// Print a list of all of the files and folders currently
	// being watched and their paths.
	   for path, f := range w.WatchedFiles() {
	     fmt.Printf("%s: %s\n", path, f.Name())
	   }

	   fmt.Println()
	*/

	// Trigger 2 events after watcher started.
	go func() {
		w.Wait()
		w.TriggerEvent(watcher.Create, nil)
		w.TriggerEvent(watcher.Write, nil)
		w.TriggerEvent(watcher.Chmod, nil)
	}()

	// Start the watching process - it'll check for changes every 100ms.
	if err := w.Start(time.Millisecond * 100); err != nil {
		log.Fatalln(err)
	}
}