간단한 프록시 서버 구현을 위한 Python

#/bin/env python 
#coding:utf-8 
import socket,select,sys,time 
import thread 
s_list = [] 
def loop(cs,addr,s_ip,s_port): 
 print '%s %d connected.' % addr 
 ts = socket.socket() 
 try: 
  ts.connect((s_ip,s_port)) 
 except: 
  cs.close() 
  print '%s %d closed.' % addr 
  sys.exit(0) 
 while True: 
  rl,wl,xl = select.select([cs.fileno(),ts.fileno()],[],[cs.fileno(),ts.fileno()]) 
  if len(xl) > 0: 
   cs.close() 
   ts.close() 
   print '%s %d closed.' % addr 
   sys.exit(0) 
  if len(rl) > 0: 
   if rl[0] == cs.fileno(): 
    rs = ts 
    ws = cs 
   else: 
    rs = cs 
    ws = ts 
   try: 
    buffer = ws.recv(10000) 
    if len(buffer) == 0: 
     raise 
    rs.send(buffer) 
   except: 
    rs.close() 
    ts.close() 
    print '%s %d closed.' % addr 
    sys.exit(0) 
def mainserver(l_port,s_ip,s_port): 
 global s_list 
 try: 
  ss = socket.socket() 
  ss.bind(('0.0.0.0',l_port)) 
  ss.listen(10) 
  s_list.append((l_port,s_ip,s_port))   
 except: 
  sys.exit(0) 
 while True: 
  cs,addr = ss.accept() 
  thread.start_new_thread(loop,(cs,addr,s_ip,s_port)) 
def manager(l_port): 
 global start,s_list 
 ss = socket.socket() 
 ss.bind(('0.0.0.0',l_port)) 
 ss.listen(10) 
 while True: 
  cs,addr = ss.accept() 
  cs.send("""trans server 1.0\r
type 'help' to get help\r
""")
  buffer = '' 
  while True: 
   buf = cs.recv(10000) 
   if len(buf) == 0: 
    cs.close() 
    break 
   if buf[-1] not in ('\r','
'): 
    buffer += buf 
    continue 
   buffer += buf 
   cmd = buffer.strip() 
   buffer = '' 
   if cmd == 'exit': 
    cs.close() 
    break 
   elif cmd == 'stop': 
    start = 0 
    cs.close() 
    sys.exit(0) 
   elif cmd == 'list': 
    b = '' 
    for l in s_list: 
     b += '%4d %s:%d\r
' % l 
    if len(b) > 0: 
     cs.send(b) 
   elif cmd in ('help','?'): 
    cs.send("""-------------------------------------------\r
exit\r 
 exit telnet\r 
start localport serverip:serverport\r 
 start a new server\r 
list\r 
 list all server\r 
-------------------------------------------\r 
""") 
   else: 
    cmds = cmd.split(" ",1) 
    if len(cmds) > 1 and cmds[0] == 'start': 
     args = cmds[1].strip().split(" ",1) 
     if len(args) != 2: 
      cs.send('start localport serverip:serverport\r
') 
      continue 
     arg = args[1].split(":",1) 
     if len(arg) != 2: 
      cs.send('start localport serverip:serverport\r
') 
      continue 
     try: 
      l_port = int(args[0]) 
      s_ip = arg[0] 
      s_port = int(arg[1]) 
     except: 
      cs.send('start localport serverip:serverport\r
') 
      continue 
     thread.start_new_thread(mainserver,(l_port,s_ip,s_port)) 
     cs.send('start OK!\r
') 
    else: 
     cs.send('no command [%s]\r
' % cmd) 
     continue 
def main(): 
 global start 
 if len(sys.argv) == 3: 
  try: 
   l_port = int(sys.argv[1]) 
   s_ip,s_port = sys.argv[2].split(":") 
   s_port = int(s_port) 
   thread.start_new_thread(mainserver,(l_port,s_ip,s_port)) 
  except: 
   pass 
 start = 1 
 thread.start_new_thread(manager,(9000,)) 
 while start: 
  time.sleep(1) 
if __name__ == '__main__': 
 start = 0 
 main()