As a newcomer (in nodes, if not time since you registered), you may want to read On asking for help and How do I post a question effectively?.

Your post would benefit from actual code as opposed to mere speculation that checksum could satisfy a part of your requirement.

And using search or Super Search or even Google (against this site alone), would lead you to several threads begun with much the same objective.

In reply to Re: checking a file for changes by ww
in thread checking a file for changes by lyle

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