1.画图整理

三次握手建立连接

四次挥手断连接

2.基于TCP开发一款远程CMD程序

​ 客户端连接服务器后，可以向服务器发送命令
​ 服务器收到命令后执行，无论执行是否成功，无论执行几遍，都将执行结果返回给客户端

注意: 执行系统指令使用subprocess模块完成.
# server.py

import socket
import subprocess

server = socket.socket()
server.bind(
    ('127.0.0.1', 8888)
)

server.listen(5)

while True:
    conn, addr = server.accept()
    print(addr)

    while True:
        try:
            cmd = conn.recv(1024).decode('utf-8')
            print('来自客户端的命令：', cmd)

            if len(cmd) == 0:
                continue

            if cmd == 'q':
                break

            res = subprocess.Popen(cmd, shell=True,
                                   stderr=subprocess.PIPE,
                                   #stdin=subprocess.PIPE,
                                   stdout=subprocess.PIPE)
            data1 = res.stdout.read()
            data2 = res.stderr.read()


            conn.send(data1 + data2)
            print('客户端中内容为：\n', (data1+data2).decode('gbk'))

        except Exception as e:
            print(e)
            break

    conn.close()
    
    
    
# client
import socket

client = socket.socket()
client.connect(
    ('127.0.0.1', 8888)
)

while True:
    cmd = input('输入命令：')
    client.send(cmd.encode('utf-8'))

    if cmd== 'q':
        break

    data = client.recv(1024).decode('gbk')
    print(data)

client.close()