Running Perl in Safe Mode

gistfile1.txt

use strict;
use warnings;

use lib "lib";
use Safe;
use Data::Dumper;
use Ar;

my $compartment = new Safe;
$compartment->permit(":load",qw(pack sort print));


our $state = {};        # Maintain state between calls.
our $debug = "";        # Debug information to print at the end.

our $ar = Ar->new({id => 1});

sub w_print {
    my ($val) = @_;
    print $val;
}

$compartment->share('w_print');
$compartment->share('$state');
$compartment->share('$ar');
$compartment->share('$debug');

my $code = <<'EOT';
    use strict;
    use warnings;

    my $s = $state;

    if (not $s->{init}) {
        $s->{init} = 1;
        $s->{counter} = 1;
    }
    else {
        $s->{counter}++;
    }
    $s->{ar} = $ar->triple_id;
    $s->{double} = $ar->double($s->{counter});
    $debug = "state: { init: ".$state->{init}.", counter: ".$state->{counter}.", double: ".$state->{double}.", }";
EOT

for (my $i = 0; $i < 10; $i++) {
    my $result = $compartment->reval($code);
    if ($@) {
        print "ERROR: $@";
        exit;
    }
}

print 'result: '.Dumper($state);

print 'debug: '.$debug."\n";
1;