for $file (@files){
     $string = "open (A$file, \"perl part2.pl $file|\")";
     eval $string; # Error checking omitted for simplicity
 }

##</code><code>##

  use Symbol qw( gensym );
  for $file (@files){
      open( my $fh= gensym(), "perl part2.pl $file |" );
      # Error checking omitted for simplicity
  }

##</code><code>##

  for $file (@files){
      system( 1, "perl part2.pl $file" );
      # Error checking omitted for simplicity
  }