Hello Monks,

I'm using Safe->reval to check if a generated perl expression is true.
I want to allow that perl expression to use a method from a custom perl module.
This method also uses Safe->reval (in a new compartment).
I can't get the nested reval to work (it works fine if called directly).

Here is the code:

The method in the custom module WOU_Util 
my $compartment = new Safe;  # module level

$compartment->permit(qw());  # module level

sub date_compare {
    my ($date, $op, $refdate) = @_;

    my ($mm_date, $dd_date, $yyyy_date) = split(/\//, $date);
    my ($mm_ref, $dd_ref, $yyyy_ref) = split(/\//, $refdate);

    my $date_str = $yyyy_date . $mm_date . $dd_date;
    my $ref_str  = $yyyy_ref  . $mm_ref  . $dd_ref;

    $compartment->reval( qq{
        ($date_str $op $ref_str) || return 0;

         # fall-through
         return 1;
    } );
}

[download]


And here's some test code that calls the method: 
#!/usr/bin/perl -w

use strict;
use Safe;
use WOU_Util;

my $compartment = new Safe;


$compartment->share_from('WOU_Util', [ 'date_compare' ] );
$compartment->permit( qw() );
  
my ($date1, $op, $date2);

$date1 = '01/02/2004';
$date2 = '01/01/2004';
$op    = 'gt';

# this prints
$compartment->reval( "print 'greater' if \"$date1\" $op \"$date2\"" );

$op = '>';
# this doesn't print, throws error
$compartment->reval( "print 'greater' if date_compare(\"$date1\",\"$op
+\",\"$date2\")" );

[download]


The error is:
Use of uninitialized value in null operation at /usr/lib/perl5/5.6.1/i386-linux/Safe.pm line 222.
(in cleanup) Undefined subroutine &Safe::Root0:: called at /usr/lib/perl5/5.6.1/i386-linux/Safe.pm line 222.

In reply to nested Safe->reval and method from custom Module by jeremyh

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.