in reply to Re^2: Monitor directories or files have any change
in thread Monitor directories or files have any change

That's probably because there is a ctrl-Z (ascii 26) somewhere in the zip file. When you renamed it to .txt, it got treated as a non-binary file and only the contents upto the (first) ctrl-Z got processed. When you appended an 'a' to it an ran it again, the same thing happened. Only the first part of the data to the first ^Z was processed. Hence the md5 didn't change.

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