由网友(发现你的脸和我巴掌好般配)分享简介：据的gz的文件大小被保存在一个.gz的文件的最后4字节的specifiction According to the specifiction of gz the filesize is saved in the last 4bytes of a .gz file.我已经创建了2个文件dd if=/dev/uran...

据的gz的文件大小被保存在一个.gz的文件的最后4字节的specifiction

According to the specifiction of gz the filesize is saved in the last 4bytes of a .gz file.

我已经创建了2个文件

dd if=/dev/urandom of=500M bs=1024 count=500000
dd if=/dev/urandom of=5G bs=1024 count=5000000

我gziped它们

I gziped them

gzip 500M 5G

我检查了最后4个字节做

I checked the last 4 bytes doing

tail -c4 500M|od -I      (returns 512000000 as expected)
tail -c4 5G|od -I        (returns 825032704 as not expected)

似乎击中无形的32位屏障，使写进ISIZE完全胡说八道的价值。这是比较烦人，比他们用了一些错误，而不是位。

It seems that hitting the invisible 32bit barrier, makes the value written into the ISIZE completely nonsense. Which is more annoying, than if they had used some error bit instead.

有谁知道的一种方式来获得pssed。广州从.gz的文件大小的uncom $ P $无解压呢？

Does anyone know of a way to get the uncompressed .gz filesize from the .gz without extracting it?

感谢

说明： http://www.gzip.org/zlib/rfc-gzip.html

编辑： 如果任何人都可以尝试一下，你可以使用/ dev / zero的，而不是为/ dev / urandom的

edit: if anyone to try it out, you could use /dev/zero instead of /dev/urandom

推荐答案

没有一个。

要得到一个COM pressed流的确切大小是实际去DECOM preSS（即使你写的一切到/ dev / null的，只是算个字节）的唯一方法。

The only way to get the exact size of a compressed stream is to actually go and decompress it (even if you write everything to /dev/null and just count the bytes).

其值得注意的是，ISIZE被定义为

Its worth noting that ISIZE is defined as

ISIZE（输入大小）               这包含原始（uncom pressed）输入的大小               数据模2 ^ 32。

ISIZE (Input SIZE) This contains the size of the original (uncompressed) input data modulo 2^32.

在GZIP RFC 所以它不是真正的破的在32位的障碍，你看到的是预期的行为。

in the gzip RFC so it isn't actually breaking at the 32-bit barrier, what you're seeing is expected behavior.