use strict;
use warnings;

use Getopt::Long;

my @wanted = ();

GetOptions(q{want=s}, \@wanted);
push @wanted, q{.} unless @wanted;

my $rxWanted;
{
    local $" = q{|};
    $rxWanted = qr{@wanted};
}
...
for my $key ( grep { m{$rxWanted} } keys %$info }
{
...
}