pp2@europa:~/LGRID-Machine/examples/matrixproduct/open2$ sed -ne '153,168p' matrix_grid.pl
foreach (@str_handles) {
  my $pid = $pm->start and next;

  $b = syswrite $_->{handle},
           join(" ",
                  $_->{chunksize},
                  $_->{A_cols},
                  @A_lines[$_->{start}.. $_->{end}],
                  @B_lines,
                  "\cN"
               );
  # Wait until the writing has finished
  # sleep(1);
  $pm->finish;
}