# $logfilename being defined previously....
  my (%errors);
  open(LOGFILE, $logfilename) or die(qq{Can't open $logfilename for input: $!\n});
    while (my $line = <LOGFILE>) {
      # example format: mon day time server program[pid]: message
      my @lineparts = split(/\s+/, $line, 6);
      if ($lineparts[5] =~ m/^Error:/) {
        $errors{$lineparts[5]}{count}++;
        push(@{$errors{$lineparts[5]}{linenumber}}, $.);
      }
    }
  close(LOGFILE);