This snippet of code:

my($boundary) = $ENV{'CONTENT_TYPE'} =~ /boundary=\"?([^\";,]+)\"?/;
[download]

Is common to both CGI and CGI::Simple. Do you have a complete test case that generates the hang? That would make it easier to debug.....

Just fire this up and point your browser to localhost. Then submit one of the last two forms and watch the hang

#!/usr/bin/perl -w

use strict;

use Cwd qw( cwd );

use File::Spec;
$ENV{DOCUMENT_ROOT} = cwd();
chdir $ENV{DOCUMENT_ROOT};

use Data::Dumper;
use HTTP::Daemon;
use HTTP::Status;
use CGI::Simple();
use CGI();

my $port    = shift || 80;
my $docroot = shift || $ENV{DOCUMENT_ROOT};

my $d = HTTP::Daemon->new(
    Reuse     => 1,
    LocalPort => $port,
) or die "No daemon: $!\n";

warn "Ready to go!\n";
while (my $conn = $d->accept())
{
    handle_uri( $conn, $conn->get_request( 1 ));
}

sub handle_uri
{
    my ($conn, $req) = @_;
    my $uri  = $req->uri();
    
    if ($uri =~ /images/)
    {
        serve_image( $conn, $req, $uri );
    }
    else
    {
        serve_everything( $conn, $req, $uri );
    }
}

sub serve_everything
{
    my ($conn, $req) = @_;
    my $uri = $req->uri;

    $ENV{REQUEST_METHOD} = $req->method;
    $ENV{CONTENT_TYPE}   = join('; ', $req->content_type ) || '';
    $ENV{CONTENT_LENGTH} = $req->content_length || '';
    $ENV{HTTP_USER_AGENT} = join('; ', $req->user_agent ) || '';
    $ENV{SCRIPT_NAME}    = $uri->path  || 1;
    $ENV{QUERY_STRING}   = $uri->query || '';
    $ENV{HTTP_HOST} = $req->header('host');
    $ENV{REMOTE_ADDR} = $conn->peerhost();
    $ENV{REMOTE_PORT} = $conn->peerport();

    foreach my $c (qw( cookie cookies ))
    {
        $ENV{uc $c} = join(';', $req->header( $c ) ) || '';
    }

    my $cgi;
    {
#        warn '$ENV{CONTENT_LENGTH} = ',$ENV{CONTENT_LENGTH},$/;
#        local $_;
#        warn "read ", sysread($conn, $_, $ENV{CONTENT_LENGTH}, 0);
#        warn $_,$/,$/;
        local *main::STDIN = $conn;
        $cgi = CGI::Simple->new();
#        $cgi = CGI->new(); # CGI works, CGI::Simple hangs :(
    }

    $conn->send_response(
        HTTP::Response->new(
            200, 'OK',
            HTTP::Headers->new(
            Set_Cookie => $cgi->cookie(
                        -name =>'sessionID',
                        -value =>'xyzzy',
                        -expires =>'+1y',
                        -path =>'',
                        -domain => $ENV{HTTP_HOST},
                        -secure => 0
                    ),
            Content_Type => "text/html"),
            "<font size=2><pre>".
                CGI::Simple->escapeHTML(
                    scalar Dumper(
                        $conn, $req, \%ENV, $cgi
                    )
                ).
qq|
</font></pre>
<hr>
<FORM
  METHOD="GET"
  ACTION="$ENV{SCRIPT_NAME}"
  ENCTYPE="application/x-www-form-urlencoded">
    <input type="text" name"f">
    <input type="reset" name=".reset" />
    <input type="submit" name=".submit" />
</form>
<FORM
  METHOD="POST"
  ACTION="$ENV{SCRIPT_NAME}"
  ENCTYPE="application/x-www-form-urlencoded">
    <input type="text" name"f">
    <input type="reset" name=".reset" />
    <input type="submit" name=".submit" />
</form>
<FORM
  METHOD="POST"
  ACTION="$ENV{SCRIPT_NAME}"
  ENCTYPE="multipart/form-data">
    <INPUT TYPE="file" NAME="upload_file1" SIZE="42">
    <INPUT TYPE="file" NAME="upload_file2" SIZE="42">
    <input type="reset" name=".reset" />
    <input type="submit">
</FORM>
|
        )
    );

    $conn->print( 'nope', $@ ) if $@;
}

sub serve_image
{
    my ($conn, $req, $uri) = @_;
    my $file = File::Spec->catfile( $docroot, $uri );
    $conn->send_status_line( (-e $file ? 200 : 404 ) );
    $conn->send_file_response( $file );
}
[download]

MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"

I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).

** The third rule of perl club is a statement of fact: pod is sexy.

The problem per se is that there is no eof reaching CGI::Simple. As a result it blocks (hangs) on the read here:

sub _read_data {
   read ( STDIN, my $buffer, 16 );  # nb changed buf size for testing
 return $buffer;
}
[download]

In essence the difference between the way CGI.pm reads data and what I did in this module is that CGI stops when it gets what it expects, thus it is not eof dependent.

It is actually quite interesting what happens. If you increase the buffer size on the read so it can slurp the data in one pass it works fine. It is only if you read bytewise that read (or sysread) fails to recognise the end of the data stream.

cheers

tachyon