#!/usr/bin/perl
#tcpserver.pl
use Switch;
use IO::Socket::INET;
	$o=0;
	$| = 1;
	$i=0; 				
	
my ($socket,$client_socket);
my ($peer_address,$peer_port);

$socket = new IO::Socket::INET ( #LocalHost => '127.0.0.1',
								  LocalPort => '5000',
								  Proto => 'tcp',
								  Listen => 5,
								  Reuse => 1) or die "ERROR in Socket Creation : $!\n";
		$timeData = scalar(localtime);
		print $timeData."\n"; 
		print "SERVER Waiting for client connection on port 5000";
		$n=0;
		$times_connected=0; # number of client connection
		$t=0;
		@connects=("");
		while(1)
		{
	# waiting for new client connection.
			$client_socket = $socket->accept();
			my $gotdata="";
			# get the host and port number of newly connected clients.
			$peer_address = $client_socket->peerhost();
			$peer_port = $client_socket->peerport();
			$_=received($peer_address,$peer_port);
		if($_)
			{
				print"\n\nCLIENT ADDRESS\t CLIENT PORT\n";
				foreach $_(0..$#client)
				{
					print $client[$_]{addr}."\t".$client[$_]{port}."\n"; 
					#Prints the list of connected clients (dumped in the array so far).
				}
			}
		else
			{ 
				sleep(20);
			}
		$times_connected++;


			print "\nAccepted New Client Connection[$times_connected] From : $peer_address, $peer_port\n at".scalar(localtime)."\n";
			while(defined(my $data=<$client_socket>))
			{
				chomp($data);
				$gotdata.=$data;
			}
			process($times_connected,$gotdata,$peerport); # processes each client details and suitably directs them.
			print "\n Data Received from Client : $gotdata\n";
			###print $client_socket $status;
		}
		$socket->close();
	
	# Process : Interprets the packet from client and instructs it do the next step
	sub process
	{
		my $client_no=shift;
		my $data=shift;
		my $port=shift;
		my @client_details=(id=>$client_no,info=>$data,port=>$port);
		my @dataElements = split(//, $data);
		if($dataElements[0] eq 0)		
		{
			if($client_no eq 1)							#if Its the very first client pinging
				{
				$status="write and get your own Md5";
				print "Get your own MD5";
				}
			else
				{ $status="take this Md5 and verify with others";
					print "verify this MD5 with already existing others";
				}

		}
		if($dataElements[0] eq 1)
		{ $status="write and Get your own MD5 ";
			print "write and Get your own MD5 ";
			#verify(@verified);
		}
		if($dataElements[0] eq 2)
		{	$status="Thanks for verifying";
			print "Thanks for verifying";
			
		}
	
	}

	# Checks for redundant client connections.
sub received
{
	$addr=shift;
	$port=shift;
	if($o eq 0)
	{	
		push @client,{addr=>$addr,port=>$port};
	}
	else
	{
		if(grep $client[$_]{port} eq $port,@client)
			{
				print "Value already exists";
				$ret=0;
			}
		else
			{
				$ret=1;
			}
 $o++;
 return $ret;
	}
}


##</code><code>##

#!/usr/bin/perl
#tcpclient.pl

use IO::Socket::INET;
my($status,$md_self,@md_others);

	$status=0;			 	
	$md=0; 				     
	@md_others=("0");        
	$md_others=join(' ',@md_others);
	$| = 1;
	
	my ($socket,$client_socket);
	print "TCP Connection Success.\n";
	# creating object interface of IO::Socket::INET modules which internally creates
	# socket, binds and connects to the TCP server running on the specific port.
	$socket = new IO::Socket::INET (PeerHost => '127.0.0.1',
									PeerPort => '5000',
									Proto => 'tcp',
									) or die "ERROR in Socket Creation : $!\n";

	
	# write on the socket to server.
	$_=join(' ',$status,$md,$md_others);
	@data=split(" ",$_);
	foreach $_(0..$#data)
	{ 
		print $socket $data[$_];
	}
	###$data=<$socket>; 
	###print $data;     
	$socket->close();