# Remove leading and trailing whitespace.
    $str =~ s{\A \* | \s* \z}{}gxm;
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That doesn't actually remove leading whitespace, it removes a leading   *   character. You probably want s{\A \s+ | \s+ \z}{}gx instead.

if ($str =~ /nbk[A-z0-9]{4}/ or /nbd[A-z0-9]{4}/ or /root/){
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The character class [A-z0-9] also matches the characters   [ \ ] ^ _ `    Did you intend to include those characters or did you really mean to use [A-Za-z0-9]?