use Algorithm::Loops qw( Filter );
my @lines = grep defined, Filter {
    s/^\s+//;
    if( /^#/ ) {
        undef $_;
    } else {
        s/\s+$//;
    }
} <$in>;

##</code><code>##

s/^\s+//, s/\s+$//
    for my @lines= grep ! /^\s*#/, <$in>;