# the HTML
<input type="submit" name="option" value="first option">

# the Perl
use CGI;
my $q = CGI->new();
my $option = $q->query('option');
[download]

The Net::Pcap, Net::PcapUtils and NetPacket module provides this kind of functionality. However, they will only parse the network layers. You're gonna have to assemble the packets and parse the HTTP headers yourself.

Here is some sample code that uses those modules to build a simple sniffer that dumps out all HTTP packets (port 80) to the screen. You must be root to run Pcap utilities since they have to open network interfaces in promiscuous mode.

#!/usr/bin/perl -w

  use strict;
  use Net::PcapUtils;
  use NetPacket::Ethernet;
  use NetPacket::IP;
  use NetPacket::TCP;
  use Data::HexDump;

  Net::PcapUtils::loop(\&process_pkt, FILTER => 'port 80');
  my $i=0;

  sub process_pkt {
    my ($user_data,$hdr,$pkt)=@_;
    my $eth=NetPacket::Ethernet->decode($pkt);
    if($eth->{type} == 2048){
      my $ip=NetPacket::IP->decode($eth->{data});
      if($ip->{proto} == 6){
        my $tcp=NetPacket::TCP->decode($ip->{data});
        print "\n\n$i $ip->{src_ip}($tcp->{src_port}) -> $ip->{dest_ip
+}($tcp->{dest_port})\n";
        print HexDump $ip->{data};
        $i++;
      }
    }
  }
[download]

They are probably voting it down because they have no idea what you are trying to ask (it wasn't me - I'm out of votes for another 12 hours or so :) I don't think it is necessarily worth voting down, but you should probably edit the original post and make the question clearer. Using the chatterbox is also an excellent technique when you want to ask a question and are not sure how to phrase it. Don't worry so much about the negative votes - just clean it up a bit, perhaps give feedback to those ho have already answered it below, and it will rise up again. Negative votes on a post can be very disheartening, but it happens to all of us. (Except vroom of course)

Getting upset at how people vote will likely get you voted down further... People tend to dislike haveing their judgement called into question like that.
Not that I've voted at all on this thread, I just started reading it, really this is an FYI for you, Macphisto.

Regards,
spectre

I wasn't commenting on their vote, I was commenting on their lack of explination. Voting me down without explaining why is just useless. It helps neither them, me, nor anyone who reads the thread.
Regards,
Macphisto

The beatings will continue until morale raises.

Macphisto: well, if it makes you feel better, I just voted this last node down because of the profanity. I appreciate that you are here and are willing to participate in the community and to be honest, I don't have any problem with profanity. My concern is that Perlmonks doesn't turn into another /. Therefore, any post with profanity, insults, or comments in a similar vein I tend to vote down on the theory that this might discourage this tendency. Other than that, it's nothing personal.

Update: This node just got voted down. I wonder who would have done that. Hmm...

Update #2: Macphisto swears that it wasn't him and for what it's worth, I believe him. We must have some scoundrel lurking in the shadows. Come out, you vile beast, and show your loathesome face!

Reminder to self: cut back on the caffeine.</font.

Ovid marches in with vroom and a couple of Friars

"There's your loathesome scoundrel, vroom!"

"Let's get that mask off, and see who it REALLY is!"

vroom yanks the ski mask from the bound monk...

*gasp* "It's Mr. Ferguson, the server maid!"

"That's right! And I would have gotten away with it, too, if it weren't for these meddling kids!"

- email Ozymandias

Note to self... take Ridalyn