Echo-Server Ver1.0

from socket import *
from signal import *
import time

def sigint_handler(signum, frame):
global is_sigint_up
is_sigint_up = True
print 'interrupt signal is up, server is cleaning up...'

signal(SIGINT, sigint_handler)
is_sigint_up = False

identify = lambda addr: '%s:%d' % (addr[0], addr[1])
local_id = identify
peer_id = identify
curr_time = lambda struct_time: '(%d-%d-%d %d:%d:%d)' % \
         (struct_time[0], \
          struct_time[1], \
          struct_time[2], \
          struct_time[3], \
          struct_time[4], \
          struct_time[5])
host = '127.0.0.1'
port = 8000
serv_addr = (host, port)
backlog = 5
buff_size = 8192
listen_sock = socket(AF_INET, SOCK_STREAM)
listen_sock.bind(serv_addr)
listen_sock.listen(backlog)
print 'echo-server is running at (%s)' % local_id(serv_addr)
conn_sock = None
peer_addr = ''

try:
while not is_sigint_up:
  conn_sock, peer_addr = listen_sock.accept()
  print 'request from %s   ...accepted' % peer_id(peer_addr)
  print 'session with %s   ...started' % peer_id(peer_addr)
  print
  
  while True:
   recv_data = conn_sock.recv(buff_size) # except socket.error
   if not recv_data: break   # for tcp, receiving none data on blocking socket
                             # means that peer has closed.
   print peer_id(peer_addr), curr_time(time.localtime())
   print ' ', recv_data
   print
   
   conn_sock.sendall(recv_data) # except socket.error
   print local_id(serv_addr), curr_time(time.localtime())
   print ' ', recv_data
   print
   
  conn_sock.close()
  print 'session with %s ending   ...finished' % peer_id(peer_addr)
  
except error, (sock_error_no, sock_error_msg):
conn_sock.close()
print sock_error_msg + '!'
print 'session with %s broken...' % peer_id(peer_addr)
print 'serve closed connect-socket!'
print

except KeyboardInterrupt:  # KeyboardInterrupt has no-effect!
                           # KeyboardInterrupt is concerned to I/O.
pass

finally:
listen_sock.close()
print 'echo-server has quited smoothly!'

raw_input('hit to quit')