Go 复制文件到另一个目录

func CopyFile(dstFileName string, srcFileName string) (written int64, err error) {
	srcFile, err := os.Open(srcFileName)
	if err != nil {
		fmt.Printf("open file err=%v\n", err)
	}
	defer srcFile.Close()

	//通过srcfile，找到Reader
	reader := bufio.NewReader(srcFile)
	//打开dstFileName
	dstFile, err := os.OpenFile(dstFileName, os.O_WRONLY|os.O_CREATE, 0666)
	if err != nil {
		fmt.Printf("open file err=%v\n", err)
		return
	}
	//通过dstFile,找到Writer
	writer := bufio.NewWriter(dstFile)
	defer dstFile.Close()
	return io.Copy(writer, reader)
}