golang把文件复制到另一个目录

//本程序 主要功能是把A文件夹下的文件与B目录下文件对比，如果找到就覆盖到B相应的目录下。 
// 用法： merge A目录 B目录 
// merge.go
package main



import (

    "flag"

    "fmt"

    "os"

    "path/filepath"

    "strings"

    "time"

        "github.com/Unknwon/com"

)



const (

    IsDirectory = iota

    IsRegular

    IsSymlink

)



type sysFile struct {

    fType  int

    fName  string

    fLink  string

    fSize  int64

    fMtime time.Time

    fPerm  os.FileMode

}



type F struct {

    files []*sysFile

}



func (self *F) visit(path string, f os.FileInfo, err error) error {

    if f == nil {

        return err

    }

    var tp int

    if f.IsDir() {

        tp = IsDirectory

    } else if (f.Mode() & os.ModeSymlink) > 0 {

        tp = IsSymlink

    } else {

        tp = IsRegular

    }

    inoFile := &sysFile{

        fName:  path,

        fType:  tp,

        fPerm:  f.Mode(),

        fMtime: f.ModTime(),

        fSize:  f.Size(),

    }

    self.files = append(self.files, inoFile)

    return nil

}



func main() {

    flag.Parse()

    sourcedir := flag.Arg(0)

    decdir := flag.Arg(1)



    source := F{

        files: make([]*sysFile, 0),

    }

    err := filepath.Walk(sourcedir, func(path string, f os.FileInfo, err error) error {

        return source.visit(path, f, err)

    })



    if err != nil {

        fmt.Printf("filepath.Walk() returned %v\n", err)

    }



    dec := F{

        files: make([]*sysFile, 0),

    }

    err = filepath.Walk(decdir, func(path string, f os.FileInfo, err error) error {

        return dec.visit(path, f, err)

    })



    if err != nil {

        fmt.Printf("filepath.Walk() returned %v\n", err)

    }



    for _, v := range source.files {



        if com.IsFile(v.fName) == true {



            tmp1 := strings.Split(v.fName, "\\")

            sourcename := tmp1[len(tmp1)-1]



            for _, r := range dec.files {

                if com.IsFile(r.fName) == true {



                    tmp2 := strings.Split(r.fName, "\\")

                    decname := tmp2[len(tmp2)-1]



                    if sourcename == decname {

                        fmt.Printf("the same file: %s\n", sourcename)

                        com.Copy(v.fName, r.fName)

                    }

                }

            }



        }

    }



}