Протоколы TCP и UDP

5.1.1.py

# -*- encoding: utf-8 -*-
"""
Обратный DNS клиент
"""
import sys, socket

try:
    result = socket.gethostbyaddr("66.249.71.15")
    print "Primary hostname:" 
    print "  " + result[0]

    # Display the list of available addresses that is also returned
    print "\nAddresses:" 
    for item in result[2]:
        print "  " + item
except socket.herror, e:
    print "Couldn't look up name:", e

5.1.2.py

# -*- encoding: utf-8 -*-
"""
TCP эхо-сервер
"""
import socket

HOST = ''                 # Symbolic name meaning all available interfaces
PORT = 50007              # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
    data = conn.recv(1024)
    if not data: break
    conn.send(data)
conn.close()

5.1.3.py

# -*- encoding: utf-8 -*-
"""
TCP клиент
"""
import socket

HOST = 'localhost'    # The remote host
PORT = 50007              # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send('Hello, world')
data = s.recv(1024)
s.close()
print 'Received', repr(data)

5.1.4.py

# -*- encoding: utf-8 -*-
"""
UDP эхо-сервер
"""
import socket, traceback

host = ''
port = 51423

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))

while 1:
    try:
        message, address = s.recvfrom(8192)
        print "Got data from", address
        s.sendto(message, address)
    except (KeyboardInterrupt, SystemExit):
        raise
    except:
        traceback.print_exc()

5.1.5.py

# -*- encoding: utf-8 -*-
"""
UDP клиент
"""
import socket, sys, time

host = sys.argv[1]
textport = "80" 

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
port = int(textport)

s.connect((host, port))
print "Enter data to transmit: " 
data = sys.stdin.readline().strip()
s.sendall(data)
s.shutdown(1)
print "Looking for replies; press Ctrl-C or Ctrl-Break to stop." 
while 1:
    buf = s.recv(2048)
    if not len(buf):
        break
    print "Received: %s" % buf