#!/usr/bin/perl -w

my @numbers = (1..24);

print "do some processing:\n";
traverseNumbers( \&doSomeProcessing );
print "do some more processing:\n";
traverseNumbers( \&doSomeMoreProcessing );

sub traverseNumbers {
  my($function) = @_;
  $count = 0;
  for (0 .. $#numbers) {
    $number = $numbers[$_];
    if (&$function($number)) {
      if($count % 10 == 0) { print "  "; }
      print sprintf(" %02d",$number);
      if($count % 10 == 9) { print "\n"; }
      $count = $count + 1;
    }
  }
  print "\n";
}

sub doSomeProcessing {
  my($number) = @_;
  sleep(1);
  return 1;
}
sub doSomeMoreProcessing {
  my($number) = @_;
  `sleep 1`;
  return 1;
}