客户端与服务端交互的基本流程

1. 服务端server

   #!/usr/bin/env python
   
   # -*- coding;utf-8 -*-
   
   import socket
   
   sk = socket.socket()
   
   sk.bind(("127.0.0.1", 9999))
   
   sk.listen(5)
   
   while True:
   
       conn, address = sk.accept()
   
       conn.sendall(bytes("欢迎访问老男孩！",encoding="utf-8"))
   
       while True:
   
           ret_bytes = conn.recv(1024)
   
           ret_str = str(ret_bytes, encoding="utf-8")
   
           print(ret_str)
   
           if ret_str == "q":
   
               break
   
           conn.sendall(bytes("答：" + "好！", encoding="utf-8"))

2. 客户端client

   #!/usr/bin/env python
   
   # -*- coding;utf-8 -*-
   
   import socket
   
   obj = socket.socket()
   
   obj.connect(("127.0.0.1", 9999))
   
   ret_bytes = obj.recv(1024)
   
   ret_str = str(ret_bytes, encoding="utf-8")
   
   print(ret_str)
   
   while True:
   
       inp = input("请输入内容：\n 问：")
   
       obj.sendall(bytes(inp, encoding="utf-8"))
   
       if inp == 'q':
   
           break
   
       else:
   
           ret = str(obj.recv(1024), encoding="utf-8")
   
           print(ret)
   
   obj.close()

粘包问题解决方案：一个类型文件发送完毕之后进行一次确认信息交互。

1. server(粘包)

   #!/usr/bin/env python
   
   # -*- coding;utf-8 -*-
   
   import socket
   
   sk = socket.socket()
   
   sk.bind(("192.168.1.107", 9999,))  # 传入元组
   
   sk.listen(5)  # 监听客户端请求，最多有五个客户端请求等待)
   
   # 连接，客户端的地址信息（IP,port)
   
   while True:
   
       conn, address = sk.accept()  # accept表示阻塞，等待连接请求
   
       conn.sendall(bytes("欢迎访问老男孩！", encoding="utf-8"))
   
       file_size = str(conn.recv(1024), encoding="utf-8")
   
       print(file_size)
   
       conn.sendall(bytes("开始吧！", encoding="utf-8"))
   
       total_size = int(file_size)
   
       has_recv = 0
   
       with open("c11.py", "wb") as f:
   
           i = 0
   
           while True:
   
               if total_size == has_recv:
   
                   print("接收完毕！")
   
                   break
   
               data = conn.recv(1024)
   
               f.write(data)
   
               has_recv += len(data)
   
   obj.close()

2. client（粘包）

   #!/usr/bin/env python
   
   # -*- coding;utf-8 -*-
   
   import socket
   
   import os
   
   obj = socket.socket()
   
   obj.connect(("192.168.1.107", 9999))
   
   result_bytes = obj.recv(1024)  # 等待发送消息
   
   result_str = str(result_bytes, encoding="utf-8")
   
   print(result_str)
   
   # 发送当前文件大小
   
   file_size = os.stat("client(粘包).py").st_size
   
   print("文件大小：" + str(file_size))
   
   obj.sendall(bytes(str(file_size), encoding="utf-8"))
   
   obj.recv(1024)
   
   with open("client(粘包).py", "rb") as f:
   
       seed_size = 0
   
       for i, line in enumerate(f, 1):
   
           obj.sendall(line)
   
           seed_size += len(line)
   
           if seed_size == file_size:
   
               print("发送完毕！")
   
   obj.close()
   

IO多路复用在socket中的运用：针对老用户和新用户，服务器做出不同的响应

1. server服务端

   #!/usr/bin/env python
   
   # -*- coding;utf-8 -*-
   
   """
   
   IO多路复用socket实例代码
   
   """
   
   import socket
   
   import select
   
   sk1 = socket.socket()
   
   sk1.bind(("127.0.0.1", 8001))
   
   sk1.listen(5)
   
   inputs = [sk1, ]
   
   info_sender = []
   
   message = {}
   
   while True:
   
       # select自动监听文件描述符，发生变化则放入r_list列表中
   
       r_list, w_list, e_list = select.select(inputs, info_sender, [], 1)
   
       # print("正在监听的对象数量：%d" % len(inputs))
   
       for sk in r_list:
   
           # sk 表示每个连接对象
   
           if sk == sk1:
   
               # 有新用户建立连接
   
               conn, address = sk.accept()
   
               conn.sendall(bytes("hello", encoding="utf-8"))
   
               inputs.append(conn)
   
               message[conn] = []
   
           else:
   
               # 有老用户发送信息
   
               try:
   
                   date = str(sk.recv(1024), encoding="utf-8")
   
               except Exception as e:
   
                   e_list.append(sk)
   
               else:
   
                   if sk not in info_sender:
   
                       info_sender.append(sk)
   
                   message[sk].append(date)
   
       for sk in w_list:
   
           re = message[sk][0]
   
           del message[sk][0]
   
           sk.sendall(bytes(re + "hello", encoding="utf-8"))
   
           # 给我发送信息的对象，我回复了信息就要把它排除，不然前面有while循环，和for循环，就会不断给对方回复消息！
   
           info_sender.remove(sk)
   
       for sk in e_list:
   
           inputs.remove(sk)
   

2. 客户端client(client1，client2，client3):当用户第一次连接时执行相同的操作，支持多用户与服务器交互，客户端断开连接，服务器不受影响

   #!/usr/bin/env python
   
   # -*- coding;utf-8 -*-
   
   import socket
   
   sk1 = socket.socket()
   
   sk1.connect(("127.0.0.1", 8001))
   
   while True:
   
       content1 = str(sk1.recv(1024), encoding="utf-8")
   
       a = []
   
       print(content1)
   
       while True:
   
           inp = input(">>>")
   
           if inp == "q":
   
               a.append(inp)
   
               break
   
           else:
   
               sk1.sendall(bytes(inp, encoding="utf-8"))
   
               content2 = str(sk1.recv(1024), encoding="utf-8")
   
               print(content2)
   
       if a == ["q"]:
   
           break
   
   sk1.close()