I'm using UTF8 mode and '\W' to evaluate the UTF8 correctness of documents. Some documents have been corrupted by previous processing. I'm stepping through the UTF8 document using a match such as 
use utf8;
$read_buf =~ m/^\W/;
$utf8_char = $&;

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When it gets to an invalid non-UTF8 character the message "Malformed UTF-8 character (byte0xff) in pattern match (m//) ... , but the match does not fail and $& holds the bad characters plus some subsequent bytes. How can I get the match to fail so I can remove the first char in the buffer.

In reply to UTF8 matches by Anonymous Monk

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