为下一个项目作准备，先写客户端的前半部分

package main

import (
	"bufio"
	"fmt"
	"io"
	"io/ioutil"
	"os"

	"path/filepath"
)

func GetAllFile(pathname string, files []string) ([]string, error) {
	fromSlash := filepath.FromSlash(pathname)
	//fmt.Println(fromSlash)
	rd, err := ioutil.ReadDir(fromSlash)
	if err != nil {
		//log.LOGGER("Error").Error("read dir fail %v\n", err)
		fmt.Println("read dir fail:", err)
		return files, err
	}
	for _, fi := range rd {
		if fi.IsDir() {
			fullDir := filepath.Join(fromSlash, fi.Name())
			files, err = GetAllFile(fullDir, files)
			if err != nil {
				fmt.Println("read dir fail:", err)
				//log.LOGGER("Error").Error("read dir fail: %v\n", err)
				return files, err
			}
		} else {
			fullName := filepath.Join(fromSlash, fi.Name())
			files = append(files, fullName)
		}
	}
	return files, nil

}

func WritetoFile(fileName string, content []string) error {
	f, err := os.OpenFile(fileName, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
	if err != nil {
		fmt.Printf("create map file error: %v\n", err)
		return err
	}
	defer f.Close()

	w := bufio.NewWriter(f)

	for _, item := range content {
		fmt.Fprintln(w, item)
	}
	return w.Flush()
}

func ReadFromFile(fileName string) ([]string, error) {
	content := []string{}
	fi, err := os.Open(fileName)
	if err != nil {
		fmt.Printf("Error: %s\n", err)
		return nil, err
	}
	defer fi.Close()

	br := bufio.NewReader(fi)
	for {
		item, _, c := br.ReadLine()
		if c == io.EOF {
			break
		}
		content = append(content, string(item))
	}
	return content, nil
}

package main

import (
	"fmt"
)

func main() {
	var oldContent, newContent []string
	logFile := "D:\\temp\\log.txt"

	oldContent, err := ReadFromFile(logFile)
	if err != nil {
		panic(err)
	}
	for i, v := range oldContent {
		fmt.Println(i, v)
	}

	newContent, err = GetAllFile("D:\\software", newContent)
	if err != nil {
		panic(err)
	}
	err = WritetoFile(logFile, newContent)
	if err != nil {
		panic(err)
	}

}