hmm... as noted above your question is vague, but considering this:
there must be a text/string based way (can't save A::D::diff output without serializing it) without files and without asking the shell for help.
I think you want to take a look at Text::Diff.

By the way, revisions in relational databases might be harder than you think, considering the "relational" part of the database. Diff et al only fix the "easy" part of the problem.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re: Revision control in relational databases by Joost
in thread Revision control in relational databases by Your Mother

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