Question

We have a custom site written in Perl that uses a slightly modified version of CGI.pm. During server updates, CGI.pm may be overwritten when it is updated. My goal is to be able to update the server without affecting the site – i.e. change the code that relies on the modified CGI.pm. Unfortunately I am not very familiar with Perl syntax or best practice.

Here is a diff of the modified CGI.pmn (line numbers are off from the most recent version of CGI.pm):

--- CGI.pm.orig Tue Nov  7 12:14:09 2006
+++ CGI.pm      Tue Nov  7 12:13:29 2006
@@ -3386,7 +3386,7 @@ sub read_multipart {
               if (defined $self->{'.upload_hook'})
                {
                   $totalbytes += length($data);
-                   &{$self->{'.upload_hook'}}($filename ,$data, $totalbytes, $self->{'.upload_data'});
+                   &{$self->{'.upload_hook'}}($filename ,$data, $totalbytes, $self->{'.upload_data'}, $param, $header{'Content-Type'});
               }
               print $filehandle $data if ($self->{'use_tempfile'});
           }

The code that relies on this diff follows:

my %file_hash = ();
my $page = new CGI(\&file_reader, \%file_hash, 0);

my $session = &get_session($page);


foreach my $param_name (keys %file_hash) {
        my $notes_param = $param_name . "_notes";
        &store_file($file_hash{$param_name}, $page->param($notes_param),
                    &get_session_name($session));
}

Without the diff, when the file is stored, the $param_name variable appears to be empty.

What is the best way to handle this? As I said before, my main goal is to simplify updates to the server; is there some way to either

a) (preferably) get %file_hash to work properly without a modified version of CGI.pm
b) prevent updates to CGI.pm (and is this a bad idea)

Answer 1

Have you tried submitting this to the CGI RT as a desired improvement? It seems reasonable to pass $param and \%header (rather than $header{'Content-Type'}) to the callback.

To answer your question, you could install CGI in a local directory. The directories in the PERL5LIB env var are searched first, so your CGI version would be found instead of the one installed by the Ubuntu.