use subs 'open';
sub open {
  print @_ . " parameters: @_\n";
  my $filehandle = shift;
  CORE::open($filehandle,@_[0..$#_]);
}
sub open2 {
    print @_ . " parameters: @_\n";
    CORE::open(@_[0..$#_]);
}

my $result;

print "Testing open...\n";
print open(TEST),$/;
print open(TEST, "test.txt"),$/;
print open(TEST, "<test.txt"),$/;
print open(TEST, "<", "test.txt"),$/;
print $/;
print "Testing open2...\n";
print open2(TEST),$/;
print open2(TEST, "test.txt"),$/;
print open2(TEST, "<test.txt"),$/;
print open2(TEST, "<", "test.txt"),$/;
print $/;