ViceRaid has asked for the wisdom of the Perl Monks concerning the following question:

hello

I've got a directory full of perl scripts that declare functions. These files are loaded into a Perl app-server when it starts up, but if any of the files either have compile errors, or don't end in a true value, the app server will stop but not start => stressed developers, grumpy editors.

To avoid this unhappy scenario, I wrote a simple test script that slurps each file in turn and uses a Safe to eval the code and catch errors before someone presses the big red restart button. I used Safe rather than eval because I wanted to prepare and manage the namespace in which the files are run, and protect the test's own namespace. I trust the code, um, morally, but I'm pretty suspicious of a lot of the older code's habit of stomping around in main::.

However, I'm finding what works in Safe on my own machine (Perl 5.8.0) doesn't work on the production box (5.6.0). I'm doing something like:


#!/usr/bin/perl

use Safe;
use Opcode;

my $code;
{ local $/; $code = <DATA> }

my $box = Safe->new();
$box->permit(Opcode::full_opset);
my $return_code = $box->reval($code);

__DATA__
use strict;
use vars qw($foo @bar);
$foo = "Friday 13th: unlucky for some";

[download]

Though this works fine in 5.8, when I run this is 5.6, it complains that '@bar requires explicit package name'. It seems that although Safe is allowing the 'use strict' declaration, it's blocking 'use vars qw(....)'.

My petition is: how can I get round this? I don't properly understand opcodes, have I done something wrong here? Or can I run this test in a different way? I'm not averse to using eval, so long as the test can control the namespace of the tested eval, and, crucially, that I don't introduce any ordering dependency into running the tests.

With thanks
ViceRaid

Replies are listed 'Best First'.
Re: Strict, safely
by broquaint (Abbot) on Jun 13, 2003 at 09:53 UTC
    That works fine for me here (v5.6.1 built for i386-linux). Which version of Safe are you using and are you using 5.6.0 or 5.6.1 (the output of perl -v would be helpful)? This doesn't appear to be an opcode issue as Safe usually issues a ... trapped by operation mask if there's a problem with the opcodes.
    HTH

    _________
    broquaint

[reply]

      No problems on:

      [alexf@localhost ~]$ perl -v
This is perl, v5.8.0 built for i386-linux-thread-multi
[alexf@localhost ~]$ perl -MSafe -e 'print $Safe::VERSION'
2.07

      [download]

      but not happy on:

      [alexf@otherhost ~]$ perl -v
This is perl, v5.6.1 built for sun4-solaris
[alexf@otherhost ~]$ perl -MSafe -e 'print $Safe::VERSION'
2.06

      [download]

      Thanks
      ViceRaid

[reply]
[d/l]
[select]
Re: Strict, safely
by ViceRaid (Chaplain) on Jun 13, 2003 at 15:05 UTC

    With thanks to broquaint, it seems like it might be down to differences in the versions of Safe installed. Unfortunately, I can't seem to find the CHANGES file for Safe on CPAN to verify whether or not this is the case.

[reply]
      Is this what you are looking for? Looks like the 2.09 version included a change which Made it work on 5.6 atleast, maybe even on 5.005?, so that may be what was causing your problems.
[reply]
[d/l]

        Thanks, but not quite. I was looking for the changes between 2.06 and 2.07, as these are the versions which aren't and are working, respectively. I tried moving the newer version (2.07) onto the older, but the newer version doesn't like to play with the older version of Opcode. Thanks again for the link.

        ViceRaid

[reply]

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