my %data;
foreach my $file (@file_list)
{
     open (INPUT, $file) || warn "Could not read $file\n";
     while (<INPUT>)
     {
          chomp;
          my ($start,$end,$name) = split (/,/);
          push (@{$data{$name}}, "$start,$end");
     }
     close (INPUT);
}

foreach (sort keys %data)
{
     print "@{$data{$_}},$_\n";
}

##</code><code>##

use Socket;
my %data;

foreach my $file (@file_list)
{
     open (INPUT, $file) || warn "Could not read $file\n";
     while (<INPUT>)
     {
          chomp;
          my ($start,$end,$name) = split (/,/);
          $start = inet_aton($start);
          $end   = inet_aton($end);
          if (defined $data{$name}{$start})
          {
                 # Resolve conflict?
          }
          else
          {
                $data{$name}{$start} = $end;
          }
     }
     close (INPUT);
}

foreach my $name (sort keys %data)
{
     foreach my $start (sort keys %{$data{$name}})
     {
          print join (',',
                      inet_ntoa($start),
                      inet_ntoa($end),
                      $name),
                "\n";
     }
}