my $code = 'my $a = shift; warn $a';

my $compartment = Safe->new(':default');
$safe = sub { $compartment->reval($code) || die $@ };
$safe->(42);
[download]

You can by sharing variables. Somehow I didn't manage to do with simply sharing a variable and localizing it, but I'm quite sure it can be done.

This is my workaround for now:

#!/usr/bin/perl
use Safe;
use IO::File;

our @args;

my $code =<<'END';
    my @args = pass_options();
    return "Arguments: @args\n";
END
my $compartment = Safe->new;
sub pass_options { @args };
$compartment->share('&pass_options');
$safe = sub { local @args = @_; $compartment->reval($code) || die $@};
print $safe->(1, 2, 3);
__END__
Arguments: 123
[download]

This takes the sideway of sharing a sub that returns the arguments. Not ideal, but at least it works.

This seems to work. The localised copy is shared into the compartments namespace.

#!/usr/bin/perl

use Safe;
use IO::File;

my $compartment = Safe->new;

my $safe = sub {
             local  @SHAREDARGS = @_;
             $compartment->share('@SHAREDARGS');
             my $code = 'print "Got: ", join (", ", @SHAREDARGS),"\n" 
+';
             $compartment->reval($code) || die "die $@"
           };

print $safe->(42, 47, 11 , "xyz");
__END__
Got: 42, 47, 11, xyz
[download]

What you want is probably:

my $code = 'sub { my $arg = shift; warn $arg; }';
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Update: Since the above looks alot like your original post, here is more.

I've never used Safe but my doc's indicate that you need a namespace as the first arg to Safe->new.

use Safe;

my $code = 'sub { my $arg = shift; warn $arg; }';

my $safe = Safe->new();

my $ssub = $safe->reval( $code) || die ;

$ssub->( "hello$/" );
&$ssub( "hello$/" );
[download]

Be well,
rir