while ( my @ready = $select->can_read()) { 
  ...
};

##</code><code>##

sleep 2; # give time to child process
while ( my @ready = $select->can_read()) { 
  ...
};

##</code><code>##

my @children = get_child_pids(); # fake
while (@children) {
  while ( my @ready = $select->can_read()) { 
    ...
  };
  @children = get_child_pids(); # fake
  sleep 5; # let's see if the remaining children will produce output
};