use subs 'open';
sub open {
  my $params = scalar @_;
  print "received $params parameters...\n";
  my $filehandle = shift;
  print "received filehandle $filehandle...\n";
  print "received list @_[0..$#_]...\n";
  my $return;
  $return = CORE::open($filehandle,@_[0..$#_]);
  return $return;
}
my $result;
$result = open(TEST);
print $result,$/;
close(TEST);
$result = open(TEST, "test.txt");
print $result,$/;
close(TEST);
$result = open(TEST, "<test.txt");
print $result,$/;
close(TEST);
$result = open(TEST, "<", "test.txt");
print $result,$/;
close(TEST);