# Modify the input array in-place
foreach my $elem (@in) {
  my ($count, $file) = split /\s+/, $elem;

  $file =~ s/^$in_prefix//;

  my ($campaign, $month, $fname) = split |/|, $file;

  $elem = {
         campaign => $campaign,
         month => $month,
         file => $fname,
         count => $count,
         sort => "$campaign:$month:$file"
  };
}