Question

我正在为自己制作一个迷你库来压缩和提取ZIP文件。到目前为止，我没有the documentation的任何重大问题，除了我没有得到ZIP文件中的“磁盘”以及如何计算磁盘的数量：

4.3.16中央目录记录结束：

end of central dir signature    4 bytes  (0x06054b50)

number of this disk             2 bytes   <= What does "disk" mean here?

number of the disk with the
start of the central directory  2 bytes   <= What does "disk" mean here?

total number of entries in the
central directory on this disk  2 bytes   <= What does "disk" mean here?

total number of entries in
the central directory           2 bytes

size of the central directory   4 bytes

offset of start of central
directory with respect to
the starting disk number        4 bytes   <= What does "disk" mean here?

.ZIP file comment length        2 bytes

.ZIP file comment       (variable size)

Answer 1

术语disk在分割和跨越ZIP文件的上下文中引用软盘（参见您提供的the documentation第8.0章;强调我的）：

8.1.1跨越是分割ZIP文件的过程多个可移动媒体。这种支持通常只有为DOS格式的软盘提供。

如今，实现通常不再支持拆分和跨越（例如here（请参阅限制）或here（请参阅过程finish_zip()）），因为软盘甚至是光盘已经消失时尚如果您没有支持拆分和跨越（首先），您可以按如下方式设置值：

number of this disk             2 bytes   <=  You only have one disk/file, so set it to 1.

number of the disk with the
start of the central directory  2 bytes   <=  You only have one disk/file, so set it to 1.

total number of entries in the
central directory on this disk  2 bytes   <=  Set it to the overall number of records.

offset of start of central
directory with respect to
the starting disk number        4 bytes   <=  Set this offset (in bytes) relative to
                                              the start of your archive.

如果要支持拆分或跨越，则每次开始写入新磁盘/文件时都必须增加磁盘数。重置每个新磁盘/文件的total number of entries in the central directory on this disk。计算相对于文件开头的偏移量。

在这个ZIP文件结构的上下文中有什么“磁盘”？

1 个答案: