# Accepts one argument: the full path to a directory.
# Returns: A list of files that end in '.html'.
sub get_new_htmls {
    my $path    = shift;

    opendir (my $dh, $path)
        or die "Unable to open $path: $!";

    my @files =
        map { $path . '/' . $_ }
        grep { !/^\.{1,2}$/ }
        readdir ($dh);

    # Rather than using a for() loop, we can just
    # return a directly filtered list.
    return
        grep { (/\.html$/) &&
               (! -l $_) }
        map { -d $_ ? get_new_htmls ($_) : $_ }
        @files;
}