Select Code to Download

my $re_single = qr/
    (?:\A|[\r\n]) # either the start of text or newline
...
        (?:\z|(?:\r\n|\n\r|\r|\n)\z) # last nl or eof
    )
/xs;

my $re_single = qr/
   ^ ( .* \n? \z )
...
/mx;

$String =~ s/\r\n|\n\r|\r|\n/\n/g;

my $re_single = qr/
    (?:\A|[\r\n]) # either the start of text or newline
...
        return( "" );
    }
}

sub Last_N_Lines {
    my ( $str, $n ) = @_;
...
}

$String =~ s/\r\n|\n\r|\r|\n/\n/g;