my (%record) = ();
     my ($packed_record);
     my ($packed_record_size) = 4+4+8;

     # Open the file and read a single record out of it.
     open (FILE, "$data_file");
     read (FILE, $packed_record, $packed_record_size);
     close (FILE);

     # Unpack the record to decode it
     ($record{'id'},$record{'time'},$record{'name'})
         = unpack ("lla8", $packed_record);

     # Make a change
     $record{time} = time;

     $packed_record = pack ("lla8", $record{'id'},$record{'time'},$record{'name'});

     open (FILE, ">$data_file");
     print $packed_record;
     close (FILE);