Expanding a bit on what robartes said, using a precompiled regular expression (qr//) might speed up the iterative loop. Because $_ is changing through each iteration of the loop:

$error=~/$_/
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/$_/ must be re-compiled each time the value of $_ changes. Though this won't matter much in this instance, because of the relatively few number of iterations, a better way to do this would be to change the contents of @regex from:

my @regex=('\bcannot verify',
             '\bcorrupt file',
             '\bskipped',
            );
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to:

my @regex=(
   qr/\bcannot verify/,
   qr/\bcorrupt file/,
   qr/\bskipped/,
);
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or even:

my @regex = map qr/$_/, (
   '\bcannot verify',
   '\bcorrupt file',
   '\bskipped',
);
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