my %dispatch = (
  'sub_one' => \&sub_one,
  'sub_two' => \&sub_two
);


$dispatch{'sub_one'}('arg');
$dispatch{'sub_two'}('arg');

sub sub_one {
  $a = shift;
  print "Got to sub one: $a\n";
}

sub sub_two {
  $a = shift;
  print "got to sub two $a\n";
}