linux - 解压缩连接两个 gzip 文件的结果是否总是等于以原始和解压缩形式连接两个文件的结果？

Question

在我的简短测试中，情况确实如此，但我想知道是否可以依赖该属性。

无论 file1 和 file2 的内容如何，​​file3 是否总是等于 file4？

cat file1 file2 > file3
gzip file1
gzip file2
cat file1.gz file2.gz | gunzip - > file4

# Are file3 and file4 necessarily the same?

Answer 1

根据手册页，是的。这是记录在案的行为。

http://www.gnu.org/software/gzip/manual/html_node/Advanced-usage.html

Advanced usage

Multiple compressed files can be concatenated. In this case, gunzip will extract all members at once. If one member is damaged, other members might still be recovered after removal of the damaged member. Better compression can be usually obtained if all members are decompressed and then recompressed in a single step.

This is an example of concatenating gzip files:

 gzip -c file1  > foo.gz
 gzip -c file2 >> foo.gz Then

 gunzip -c foo is equivalent to

 cat file1 file2