How to compare a .gz and a txt file

[Peng Yu]

Suppose I have a file xxx.txt.gz and a file xxx.txt, I'm wondering how
to compare the content inside xxx.txt.gz with xxx.txt without first
explicitly gunzip xxx.txt.gz (I want to avoid creating a temp file
because both xxx.txt.gz and xxx.txt are huge). Is there just one
command allowing me to compare xxx.txt.gz and xxx.txt?

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Regards,
Peng