for (sort third_field <INPUT>) {
  print "Record: $_";
}

sub third_field {
  my $x = (split ' ', $a)[2];
  my $y = (split ' ', $b)[2];
  $x <=> $y;
}

##</code><code>##

for (by_third_field <INPUT>) {
  print "Record: $_";
}

sub by_third_field {
  map $_->[0],
  sort { $a->[3] <=> $b->[3] }
  map { [ $_, split ] }
  @_;
}