5：golang获取文件夹大小

//getFileSize get file size by path(B)
func DirSizeB(path string) (int64, error) {
    var size int64
    err := filepath.Walk(path, func(_ string, info os.FileInfo, err error) error {
        if !info.IsDir() {
            size += info.Size()
        }
        return err
    })
    return size, err
}

//getFileSize get file size by path(B)
func getFileSize(path string) int64 {
    if !exists(path) {
        return 0
    }
    fileInfo, err := os.Stat(path)
    if err != nil {
        return 0
    }
    return fileInfo.Size()
}

//exists Whether the path exists
func exists(path string) bool {
    _, err := os.Stat(path)
    return err == nil || os.IsExist(err)
}