You can just try to decode it as UTF-8, and fall back to cp-1252 if it didn't work. See Encode, section "Handling Malformed Data".
Perl 6 - second systems done right

In reply to Re: What's the best way to detect character encodings, Windows-1252 v. UTF-8? by moritz
in thread What's the best way to detect character encodings, Windows-1252 v. UTF-8? by Jim

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