Mod CGI problems with POST

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

Good day bretheren. I am trying to use mod CGI with POST input and am getting a stange error. Here is the (simplified) code:

#!/usr/bin/perl -w
use strict;
use HTTP::Daemon;
use CGI qw/:standard/;
my $d = HTTP::Daemon->new(LocalPort => 8080) || die;
while (my $c = $d->accept) {
    while (my $r = $c->get_request) {
        my $uri = $r->uri;
        $ENV{REQUEST_METHOD} = $r->method;
        $ENV{CONTENT_TYPE}   = join('; ', $r->content_type) || '';
        $ENV{CONTENT_LENGTH} = $r->content_length  || '';
        $ENV{SCRIPT_NAME}    = $uri->path  || 1;
        $ENV{QUERY_STRING}   = $uri->query || '';   
        my $q = new CGI;
        my $reply;
        my $scriptname = $ENV{'SCRIPT_NAME'};
        #$q =  new CGI;
        if ($scriptname =~ /start/) {
            $reply = $q->header;
            open(IN,"test.htm") or die "Can't open input: $!\n";
            while(<IN>) {
                $reply .= $_;
            }
            close IN;
        }
        elsif ($scriptname eq '/process') {
            my @params = $q->param;
            $reply = $q->header;
            $reply .= $q->start_html.$q->h2("Parameters").join('<br>',
+@params).$q->end_html;          
        }
        $c->send_response($reply);
    }
    $c->close;
    undef($c);
}
[download]

and here is the test.htm it uses

<html>
<body>
<form method="post" action="process" enctype="multipart/form-data">
<input type="checkbox" name="cb" value="on" /><input type="text" name=
+"label" value="foobar" size="40" />
<input type="submit" name=".submit" />
</form>
</body>
</html>
[download]

I get the initial page with localhost:8080/start. Upon clicking SUBMIT I get error Use of uninitialized value in pattern match (m//) at (eval 22)[C:/Perl/site/lib/CGI.pm:829] line 4.. If I step through the code with the (Komodo) debugger, it goes into an infinite wait at my $q = new CGI;. I found that if I delete the enctype argument from the form tag in the htm file, I get no error and the infinite wait, debugger or no.

I found this thread that seems to discuss a similar problem, but it's talking about file uploads and anyway is four years old so I would think that this particular bug has been worked out by now.

Anyone know what the problem is here?

Thx...Steve

Edit: g0n - corrected link format

Update: In the code above I commented out the second CGI constructor, a mistake caught by Chromatic. But that didn't fix the problem. Also based on his opinion that CGI didn't have the proper filehandle, and the old thread linked above, I tried inserting local *main::STDIN = $c; right before the CGI constructor, and that didn't fix things either.

Comment on Mod CGI problems with POST Select or Download Code

Replies are listed 'Best First'.
Re: Mod CGI problems with POST by chromatic (Archbishop) on May 31, 2007 at 00:33 UTC
The problem is that you're creating two CGI objects: `my $q = new CGI; ... q = new CGI;` [download] Only the first one can read the POST body from `STDIN`. When the second one tries to read it, the stream is gone, and you've overwritten the original object, so the data is gone too.	[reply] [d/l] [select]
Re^2: Mod CGI problems with POST by cormanaz (Deacon) on May 31, 2007 at 01:20 UTC
Good catch, but I removed the second one and the problem persists.	[reply]
Re^3: Mod CGI problems with POST by chromatic (Archbishop) on May 31, 2007 at 06:07 UTC
Oh, right. I overlooked HTTP::Daemon. The problem now is that CGI expects to read from STDIN, but you have another filehandle from which you want to read. I sent Lincoln a patch a long, long time ago to pass in a filehandle from which CGI should read, but I don't know if he ever applied it. I remember doing something similar with CGI::Simple instead.	[reply]
Re^4: Mod CGI problems with POST by cormanaz (Deacon) on May 31, 2007 at 14:45 UTC
Re^5: Mod CGI problems with POST by chromatic (Archbishop) on May 31, 2007 at 18:10 UTC
Re: Mod CGI problems with POST by derby (Abbot) on May 30, 2007 at 23:54 UTC
Well ... what's on line 829 of CGI.pm (on my version 3.15 it's nothing). More than likely it's the line where $ENV{CONTENT_TYPE} is checked as to whether or not the data is application/x-www-form-urlencoded or multipart/form-data. Is that being sent by your client (or set by your server)? -derby Update: Normally that infinite loop in CGI is when CGI thinks it's in DEBUG mode and no GET nor POST data is sent (or none was recognized - bad content type) - it's waiting for input on STDIN.	[reply]
Re^2: Mod CGI problems with POST by cormanaz (Deacon) on May 31, 2007 at 01:19 UTC
I've got ver 3.20 and lines 827 thru 831 are `eval "package $pack; $code"; if ($@) { $@ =~ s/ at .*\n//; croak("$AUTOLOAD: $@"); }` [download] this is in sub _compile. If the content_type is as set by the FORM tag in the sample HTML file, the the content_type that comes through in the environment variable is `multipart/form-data; boundary=---------------------------24805226817341` and the behavior is as I described with either the pattern match error or infininte wait if I debug. If I delete that parameter from the FORM statement the content_type is application/x-www-form-urlencoded and I get the infinite wait whether I run straight through or debug.	[reply] [d/l] [select]
Re: Mod CGI problems with POST by stonecolddevin (Parson) on May 30, 2007 at 22:36 UTC
Ignore this b.s. didn't check to make sure it was accurate. You can't create a CGI object when you're using the `:standard` function oriented interface. Change `use CGI qw/:standard/;` to `use CGI;` and your object will be created properly meh.	[reply] [d/l] [select]