G'day kcott,

just wondering:

    my @keeps = qw{a b};
    my %to_keep = map { $_ => 1 } @keeps;
...
        delete @$sms_ref{ grep { ! exists $to_keep{$_} } keys %$sms_re
+f };
[download]

using exists is a bit redundant if you already intialize the hash with true values...

so either dropping the exists

...
        delete @$sms_ref{ grep { ! $to_keep{$_} } keys %$sms_ref };
[download]

or initializing with undef

    my %to_keep;
    @to_keep{ qw{a b} } = ();
...
[download]

should have the same effect.

Or am I missing something?