#!usr/bin/perl

use Parallel::ForkManager;

my $MAX_PROCESSES=10;

$pm = new Parallel::ForkManager($MAX_PROCESSES);

$pm->run_on_finish(
    sub {
      my ($pid, $exit_code, $ident, $signal, $core) = @_;
      print "$pid $exit_code $ident $signal $core\n";
    }
  );

foreach ( a .. f ) {
  my $pid = $pm->start($_) and next;
  my $exit_code = 40;
  $pm->finish($exit_code);
}