Welcome to the Perl Tutor!

Special commands are:
(H)elp      Get online help.
(L)oad      Load and evaluate the contents of the file.
(V)ars      Look at the present values of variables.
(C)lear     Clears the values of all variables and removes all undo data.
(B)lock     Type in more than one line of code at a time.
(U)ndo      Undo last Perl command.
(Q)uit      Quit the Perl Tutor.

Anything which is not a special command will be evaluated as Perl code.
> sub foo { $_ = shift; return $_ x 3 }

> $bar = foo("42 ");

> @baz = (1, 2, 3, 4);

> %quux = @baz

> vars
$bar = "42 42 42 "
@baz = (1, 2, 3, 4)
sub foo { ... }
%quux = (1 => 2, 3 => 4)
> undo
Successfully executed `undo' command.
> vars
$bar = "42 42 42 "
@baz = (1, 2, 3, 4)
sub foo { ... }
> quit