#!/usr/bin/perl
use locale;

my @list = ('maceira', 'mac alister', 'mac loughlin', 'san esteban', 'sangregorio', 'san zoilo');

sub keeping_spaces {
  my $aa = $a;
  my $bb = $b;
  for ($aa) {
    tr/ /A/;
  }
  for ($bb) {
    tr/ /A/;
  }
  return $aa cmp $bb;
}

print "$_\n" for sort keeping_spaces @list;

##</code><code>##

mac alister
mac loughlin
maceira
san esteban
san zoilo
sangregorio