serv.pl

use strict;
use IO::Socket;

my $serv = IO::Socket::INET->new(Listen => 10, LocalPort => 8080)
	or die $@;

my $header = join(
	"\r\n",
	"HTTP/1.1 200 OK",
	"Server: nginx/1.0.4",
	"Date: Thu, 06 Oct 2011 16:14:01 GMT",
	"Content-Type: text/html",
	"Transfer-Encoding: chunked",
	"Connection: keep-alive",
	"Vary: Accept-Encoding",
	"X-Powered-By: PHP/5.3.6",
	"\r\n"
);

my @chunks = (
	'This is the data in the first chunk ',
	'and this is the second one ',
	'con',
	'sequence'
);

while (my $client = $serv->accept()) {
	my $req;
	while ($req !~ /\r\n\r\n$/) {
		$client->sysread($req, 1024, length $req) or die $!;
	}
	
	$client->syswrite($header);
	for my $c (@chunks) {
		$client->syswrite(sprintf("%x\r\n", length $c));
		sleep 1;
		$client->syswrite($c."\r\n");
	}
	$client->syswrite("0\r\n\r\n");
}

t.pl

use strict;
use Net::HTTP::NB;
use Data::Dumper;

my $s = Net::HTTP::NB->new(Host => "localhost:8080") || die $@;
$s->write_request(GET => "/", 'User-Agent' => "Mozilla/5.0");

use IO::Select;
my $sel = IO::Select->new($s);
 
READ_HEADER: {
   die "Header timeout" unless $sel->can_read(10);
   my($code, $mess, %h) = $s->read_response_headers;
   redo READ_HEADER unless $code;
   
   print Dumper $code, $mess, \%h;
}

while (1) {
   die "Body timeout" unless $sel->can_read(10);
   my $buf;
   my $n = $s->read_entity_body($buf, 1024);
   last unless $n;
   print $buf;
}