CLIENT-SERVER Communicator v1.0

README.md

#CLIENT-SERVER Communicator v1.0

• Author: Rohit Dua
• Email: 8ohit.dua AT gmail DOT com
• LICENSE : GNU GENERAL PUBLIC LICENSE Version 3

The program dipicts a simple client server program using socket programming. The client accepts arguments('sender' or 'receiver') The server accepts connections from client via a separate thread.

###Usage:

• Run the server (python my_server.py)
• Run the sender client (python my_client.py sender)
• Run the receiver client (python my_client.py receiver)

###Contribution: For contributions we follow PEP8 rules for python formatting(yapl for automating it). Please report all bugs and issues on Github.

LICENSE

                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

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                       TERMS AND CONDITIONS

  0. Definitions.

  "This License" refers to version 3 of the GNU General Public License.

  "Copyright" also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.

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work under this License, and how to view a copy of this License.  If
the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.

  1. Source Code.

  The "source code" for a work means the preferred form of the work
for making modifications to it.  "Object code" means any non-source
form of a work.

  A "Standard Interface" means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming la

my_client.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# @author Rohit Dua <8ohit.dua AT gmail DOT com>

# For Sender client: python my_client.py sender
# For Receiver client: python my_client.py receiver

import my_socket
import time
import sys
from sys import stdout


def main():
    if len(sys.argv) < 2:
        print "Insufficient arguments"
        sys.exit(1)
    if 'sender' in sys.argv[1].lower():
        client_type = 2
        print "SENDER CLIENT\n============="
    elif 'receiver' in sys.argv[1].lower():
        client_type = 1
        print "RECEIVER CLIENT\n==============="
    else:
        print "Invalid argument.\nChoose sender or receiver"
        sys.exit(1)
    c = my_socket.Client(client_type=client_type)
    if client_type == 2:
        while True:
            data = raw_input(">>")
            c.send(data)
    else:
        while True:
            data = c.receive()
            try:
                stdout.write(data.next())
                stdout.flush()
            except StopIteration:
                time.sleep(0.1)
                continue


if __name__ == '__main__':
    sys.exit(main())

my_server.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# @author Rohit Dua <8ohit.dua AT gmail DOT com>

import my_socket
import time
import sys
from sys import stdout


def main():
    print "SERVER\n======"
    s = my_socket.Server()
    while True:
        data = s.receive()
        try:
            ch = data.next()
            stdout.write(ch)
            stdout.flush()
        except StopIteration:
            time.sleep(0.1)
            continue
        s.send(ch)


if __name__ == '__main__':
    sys.exit(main())

my_socket.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# @author Rohit Dua <8ohit.dua AT gmail DOT com>

import socket
import sys
import threading
import time
from random import randint
from sys import stdout

HOST = socket.gethostname()
PORT = 2  # random runtime generated


def print_it(data, verbose):
    if verbose:
        print data


class Server:
    def __init__(self, host=HOST, verbose=True):
        self.verbose = verbose
        global PORT
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try_ports = True
        while try_ports is True:
            try:
                PORT = randint(1025, 9000)
                s.bind((host, PORT))
                f = open('.port', 'w')
                f.write(str(PORT))
                f.close()
                try_ports = False
                print_it("Listening on port " + str(PORT), self.verbose)
            except socket.error as msg:
                if msg[0] == 98:  # Port already in use
                    continue
                else:
                    print_it('Error Code:: ' + str(msg[0]) + ', Message ' +
                             msg[1], self.verbose)
                    sys.exit()
        self.s = s
        self.running = True
        t = threading.Thread(target=self.handle_requests)
        t.start()
        self.t = t
        self.clients = []
        self.receiver_client = None
        self.sender_client = None

    def handle_requests(self, max_queue=1):
        """Accept client requests(run in thread)"""
        self.s.listen(max_queue)
        self.s.settimeout(10)
        while self.running:
            try:
                c, addr = self.s.accept()
                client_type = self.receive(client=c, limit=1)
                print_it("\nNew client connected:", self.verbose)
                if client_type.next() in (1, '1'):
                    print_it("Type: Receiver", self.verbose)
                    self.receiver_client = c
                else:
                    print_it("Type: Sender", self.verbose)
                    self.sender_client = c
            except:
                pass

    def send(self, data, client=None):
        """Send data to sender client"""
        if client is None:
            return self.receiver_client.send(data)
        else:
            return client.send(data)

    def receive(self, client=None, limit=0):
        """Receive data from receiver client"""
        received_data = ""
        while self.sender_client is None and limit != 1:
            time.sleep(1)
        while True:
            if client is None:
                ch = self.sender_client.recv(1)
            else:
                ch = client.recv(1)
            if limit == 1:
                yield ch
                return
            yield ch

    def close(self):
        self.running = False
        self.s.shutdown(socket.SHUT_RDWR)


class Client:
    def __init__(self, host=HOST, client_type=2, verbose=True):
        """Requests server for connection and identify as sender/receiver"""
        f = open('.port', 'r')
        port = int(f.read())
        f.close()
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((host, port))
        self.s = s
        if client_type == 2:
            self.send('2')
        else:
            self.send('1')

    def send(self, data):
        return self.s.send(data)

    def receive(self):
        received_data = ""
        while True:
            ch = self.s.recv(1)
            yield ch

    def close(self):
        self.s.close()

my_unit_test.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# @author Rohit Dua <8ohit.dua AT gmail DOT com>

import unittest
import time

from my_socket import Server, Client


class MyTest(unittest.TestCase):
    def setUp(self):
        self.server = Server(verbose=False)
        self.sender_client = Client(client_type=2, verbose=False)
        self.receiver_client = Client(client_type=1, verbose=False)
        time.sleep(0.001)

    def test_server_send(self):
        self.assertEqual(self.server.send('foo'), 3)

    def test_client_send(self):
        self.assertEqual(self.sender_client.send('foo'), 3)

    def test_server_receive(self):
        self.sender_client.send("bar")
        recv = self.server.sender_client.recv(3)
        self.assertEqual(recv, "bar")

    def test_client_receive(self):
        self.server.send("bar")
        recv = self.receiver_client.s.recv(3)
        self.assertEqual(recv, "bar")

    def tearDown(self):
        self.server.close()
        self.sender_client.close()
        self.receiver_client.close()


if __name__ == '__main__':
    unittest.main()