NAME
    Safe::Hole - make a hole to the original main compartment in the Safe
    compartment

SYNOPSIS
      use Safe;
      use Safe::Hole;
      $cpt = new Safe;
      $hole = new Safe::Hole {};
      sub test { Test->test; }
      $Testobj = new Test;
      # $cpt->share('&test');  # alternate as next line
      $hole->wrap(\&test, $cpt, '&test');
      # ${$cpt->varglob('Testobj')} = $Testobj;  # alternate as next line
      $hole->wrap($Testobj, $cpt, '$Testobj');
      $cpt->reval('test; $Testobj->test;'); 
      print $@ if $@;
      package Test;
      sub new { bless {},shift(); }
      sub test { my $self = shift; $self->test2; }
      sub test2 { print "Test->test2 called\n"; }

DESCRIPTION
      We can call outside defined subroutines from the Safe compartment
    using share(), or can call methods through the object that is copied
    into the Safe compartment using varglob(). But that subroutines or
    methods are executed in the Safe compartment too, so they cannot call
    another subroutines that are dinamically qualified with the package
    name such as class methods nor can they compile code that uses opcodes
    that are forbidden within the compartment.

      Through Safe::Hole, we can execute outside defined subroutines in the 
    original main compartment from the Safe compartment. 

      Note that if a subroutine called through Safe::Hole::call does a
    Carp::croak() it will report the error as having occured within
    Safe::Hole.  This can be avoided by including Safe::Hole::User in the
    @ISA for the package containing the subroutine.

  Methods
    new [NAMESPACE]
        Class method. Backward compatible constructor. NAMESPACE is the
        alternate root namespace that makes the compartment in which call()
        method execute the subroutine. Default of NAMESPACE means the
        current 'main'. This emulates the behaviour of Safe-Hole-0.08 and
        earlier.

    new \%arguments
        Class method. Constructor. The constructor is called with a hash
        reference providing the constructor arguments. The argument ROOT
        specifies the alternate root namespace for the object. If the ROOT
        argument is not specified then Safe::Hole object will attempt
        restore as much as it can of the environment in which it was
        constrtucted. This includes the opcode mask, %INC and @INC. If a
        root namespace is specified then it would not make sense to restore
        the %INC and @INC from main:: so this is not done. Also if a root
        namespace is given the opcode mask is not restored either.

    call $coderef [,@args]
        Object method. Call the subroutine refered by $coderef in the
        compartment that is specified with constructor new. @args are passed
        as the arguments to the called $coderef. Note that the arguments are
        not currently passed by reference although this may change in a
        future version.

    wrap $ref [,$cpt ,$name]
        Object method. If $ref is a code reference, this method returns the
        anonymous subroutine reference that calls $ref using call() method
        of Safe::Hole (see above). If $ref is a class object, this method
        makes a wrapper class of that object and returns a new object of the
        wrapper class. Through the wrapper class, all original class methods
        called using call() method of Safe::Hole. If $cpt as Safe object and
        $name as subroutine or scalar name specified, this method works like
        share() method of Safe. When $ref is a code reference $name must
        like '&subroutine'. When $ref is a object $name must like '$var'.
        Name $name may not be same as referent of $ref. For example:
        $hole->wrap(\&foo, $cpt, '&bar'); $hole->wrap(sub{...}, $cpt,
        '&foo'); $hole->wrap($objfoo, $cpt, '$objbar');

    root
        Object method. Return the namespace that is specified with
        constructor new(). If no namespace was then root() returns 'main'.

  Warning
    You MUST NOT share the Safe::Hole object with the Safe compartment. If
    you do it the Safe compartment is NOT safe.

    This module provides a means to go from a state where an opcode is
    denied back to a state where it is not. Reasonable care has been taken
    to ensure that programs cannot simply manipulate the internals to the
    Safe::Hole object to reduce the opmask in effect. However there may
    still be a way that the authors have not considered. In particular it
    relies on the fact that a Perl program cannot change stuff inside the
    magic on a Perl variable. If you install a module that allows a Perl
    program to fiddle inside the magic then this assuption breaks down. One
    would hope that any system that was running un-trusted code would not
    have such a module installed.

AUTHORS
    Sey Nakajima <nakajima@netstock.co.jp> (Initial version)

    Brian McCauley <nobull@cpan.org> (Maintenance)

    Todd Rinaldo <toddr@cpan.org> (Maintenance)

SEE ALSO
    Safe(3).