my $fh;
  open($fh,'<',$file);
  while (<$fh>) {
    print "line: $_\n";
  }

##</code><code>##

  my $fh;
  $fh = cacheout('<',$file);
  while (<$fh>) {
    print "line: $_\n";
  }

##</code><code>##

readline() on unopened filehandle 1 at ...
readline() on unopened filehandle 2 at ...
readline() on unopened filehandle 3 at ...
...