...
   foreach (@jobs) {
      &process($_);
   }
   ...

##</code><code>##

   ...
   foreach (@jobs) {
      die "Fork failed: $!\n" unless defined (my $pid = fork);
      exit &process($_) unless $pid;
   }
   1 until -1 == wait;
   ...

##</code><code>##

   ...
   my $max = 4;
   my $c   = 0;
   foreach (@jobs) {
      wait unless ++$c <= $max;
      die "Fork failed: $!\n" unless defined (my $pid = fork);
      exit &process($_) unless $pid;
   }
   1 until -1 == wait;
   ...