my $ref->{number} = 123;
my $arg = shift ( @ARGV ) ;
my $regex = qr/(one|two|three|four)/;

for (1..10) {
  if ( ref $ref eq 'HASH' and $arg =~ /$regex/ig ) {
    print "$arg matches\n";
  } else {
    print "$arg doesn't match\n";
  }
}