Re: Passing argument into STDIN inside safe.pm reval

[7stud]

You can insert your program's STDIN filehandle into the compartment like this:

use strict;
use warnings;
use 5.012;

use Safe;

if($ARGV[0]) {
    my $code = $ARGV[0];
    my $compartment = Safe->new;
    my $namespace_name = $compartment->root();
      
    {
        no strict;
        *{$namespace_name . "::STDIN"} = *main::STDIN;
    }


    $compartment->deny_only(qw(chdir));  #<----CHECK THIS***
    $compartment->reval($code);

    if ($@) {
        print "Unsafe code detected: $@";
    }

}

--output:--
$ $ perl 2.pl '
print "Enter some stdin: ";
my $line = <STDIN>;
print "From STDIN: $line";
'
Enter some stdin: hello
From STDIN: hello

But I can't figure out how to permit_only() what is necessary for the line input operator(<$infile>) to work. I tried permit_only(qw{ print <> }), which produced the error:

Unknown operator prefix "<>"

And because perlop says:

<FILEHANDLE> may also be spelled readline(*FILEHANDLE). 

I tried permit_only(qw{ print readline }), but that produced this error:

Unsafe code detected: 'private value' trapped by operation mask at (ev
+al 5) line 1.


use strict;
use warnings;
use 5.012;

use Safe;

if($ARGV[0]) {
    my $code = $ARGV[0];
    my $compartment = Safe->new;
    my $namespace_name = $compartment->root();
      
    {
        no strict;
        *{$namespace_name . "::STDIN"} = *main::STDIN;
    }


    $compartment->permit_only(qw(print readline));
    $compartment->reval($code);

    if ($@) {
        print "Unsafe code detected: $@";
    }

}

--output:--
$ perl 2.pl '
print "Enter some stdin: ";
my $line = readline *STDIN;
print "From STDIN: $line";
'
Unsafe code detected: 'private value' trapped by operation mask at (ev
+al 5) line 1.