$ perl -wle'
use HTML::Template::Compiled;
my $htc = HTML::Template::Compiled->new(
    plugin => [qw(::HTML_Tags)],
    scalarref => \"<%html_option switch_ips %>",
);
$htc->param(
    switch_ips => [undef, "127.0.0.1", "127.0.0.2", "127.0.0.3", "127.0.0.4"] 
);
print $htc->output'
<option value="127.0.0.1" >127.0.0.1</option>
<option value="127.0.0.2" >127.0.0.2</option>
<option value="127.0.0.3" >127.0.0.3</option>
<option value="127.0.0.4" >127.0.0.4</option>