I beg the indulgence of the Monks. I posted this last week under the heading of XML::Twig->parse() error under CGI and I am resubmitting this issue under the above heading to provide some additional data, and to see if we can have another look at this issue. As mirod has pointed out, XML::Twig is not involved with the problem that I am having except as a messenger of the bad news.

The Situation:

I have written a module that reads in log files (which are in XML) and parses them for various conditions to provide some reporting on my EAI engine (all Perl, all the time). The package uses mirod's XML::Twig to set up handlers for different conditions to report on, and I use it to create a web page that our users can view to see errors and successes, and to post-process the results.
After I developed the module I tested it with a script and everything works just fine. When I call the same package from a CGI program I get an error from XML::Expat

The Problem:

Here is the error message that I am getting from XML::Expat:

Can't use string ('<myXMLString><myElement name="foo"-') as a 
symbol ref while "strict refs" in use at 
.../perl5/site_perl/5.6.0/sun4-solaris-thread/XML/Parser/Expat.pm 
line 456.
[download]

If you look at the code at that point, you will see the following:

sub parse {
  my $self = shift;
  my $arg = shift;
  croak "Parse already in progress (Expat)" if $self->{_State_};
  $self->{_State_} = 1;
  my $parser = $self->{Parser};
  my $ioref;
  my $result = 0;

  if (defined $arg) {
    if (ref($arg) and UNIVERSAL::isa($arg, 'IO::Handle')) {
      $ioref = $arg;
    } elsif (tied($arg)) {
      my $class = ref($arg);
      no strict 'refs';
      $ioref = $arg if defined &{"${class}::TIEHANDLE"};
    }
    else {
      eval {
        $ioref = *{$arg}{IO};  # This is line 456
      };
      undef $@;
    }
  }
[download]

So the offending line is where "$ioref = *{$arg}{IO};". In this case, $arg happens to be my XML string, which is the correct thing for it to be. If you push the scripty version of this though the debugger, all values appear correct, and the globbing works fine under use strict.

My thoughts:

• Some have suggested that the version of XML::Expat is one that the web-server is using, and is therefore different than my test script. I don't think that this is true, due to the fact that the error message explicitly has the path of the version of Expat.pm that I expect, and know is the right path.
• It is possible that the version of Perl is different on the command line that the one the webserver calls, even though the include path is fine. Might this have an impact? If so I can rebuild the Perl that Apache uses. Does the kerbang in my .pl have any bearing on which Perl the webserver uses?
• I suppose I can take the "no strict 'refs';" line and copy it into the section in the Expat.pm or move it up block-wise. I would like to avoid this, since when I move the code into production, that could be a difficult luxury.

If anyone else has any ideas I would appreciate it. Thanks so much to those who have already made suggestions.

Brian - a.k.a. DrSax

Edited 2001-05-29 by Ovid

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