Well, after you asked the question I looked back at the code and found it actually looked like the follow (more code context included): 

$buf = "hello\nworld";
$l = length($buf);

for ($x = 0; $x < $l; $x++) {
    $piece = substr($buf, $x, 1);
    $i = ord($piece);
 
    if ($i =~ m/[ -~]/) {
        $rhs .= $i;
    } else {
        $rhs .= ".";
    }
}

[download]

So, the error is actually mine and works fine when using the right variable, $piece, as: 

    if ($piece =~ m/[ -~]/)

[download]

Sorry for the wasted space to post this question.

In reply to Re^2: regex incorrectly matching newline by bfdi533
in thread regex incorrectly matching newline by bfdi533

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