你的第一个C/S程序

socket

socket基础知识

服务端代码

import socket
import threading
import time

MSG_LENGTH = 64
DISCONNECTED = '!CONNECTION CLOSED'
connections = 0

#定义服务器地址
server_ip = socket.gethostbyname(socket.gethostname())
server_port = 5555
server_addr = (server_ip, server_port)

#创建服务器套接字并绑定到工作地址
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.bind(server_addr)

def handle_client(client_socket, client_addr):
    print(f'新连接建立，远程客户机地址是：{client_addr}'+'\n')
    connected = True
    while connected:
        try:
            msg_len = client_socket.recv(MSG_LENGTH).decode('utf-8') #接收消息长度
        except ConnectionResetError:
            global connections
            connections -= 1
            print(f'远程客户机{client_addr}关闭了连接,活动连接数量是：{connections}')
            break;
        msg_len = int(msg_len)
        if msg_len > 0:
            msg = client_socket.recv(msg_len).decode('utf-8') # 接收消息内容
            if msg == DISCONNECTED: # 收到客户机断开连接的消息
                connected = False
                print(f'客户机：{client_addr}断开了连接！')
                connections -= 1
                print(f'服务器当前活动连接数量是：{connections}')
            print(f'来自客户机{client_addr}的消息是：{msg}')
            # 回送消息
            echo_message = f'服务器{client_socket.getsockname()}收到消息：{msg},时间：{time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())}'
            client_socket.send(echo_message.encode('utf-8'))
    client_socket.close() # 关闭会话连接

server_socket.listen()
print(f'服务器开始在{server_addr}侦听...')

while True:
    new_socket, new_addr = server_socket.accept()
    client_thread = threading.Thread(target=handle_client, args=(new_socket, new_addr))
    client_thread.start()
    connections += 1
    print(f'服务器当前活动连接数量是：{connections}')

客户端代码

import socket

MSG_LENGTH = 64
DISCONNECTED = '!CONNECTION CLOSED'

remote_ip = socket.gethostbyname(socket.gethostname())
remote_port = 5555
remote_addr = (remote_ip, remote_port)

client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect(remote_addr)
print(f'客户机工作地址：{client_socket.getsockname()}')

def send_recv(msg):
    message = msg.encode('utf-8') # 消息编码 发消息需编码
    msg_len = len(message) # 消息长度
    str_len = str(msg_len).encode('utf-8') # 长度编码
    str_len += b' ' * (MSG_LENGTH - len(str_len)) # 空白处补空格
    client_socket.send(str_len) # 发送消息长度
    client_socket.send(message) # 发送消息内容
    echo_message = client_socket.recv(1024).decode('utf-8') # 接收服务器消息
    print(echo_message)

while True:
    inputStr = input('请输入待发送的字符串(Q:结束会话）：')
    if inputStr.lower() == 'q':
        break
    send_recv(inputStr) # 发送消息和接收消息

send_recv(DISCONNECTED)
client_socket.close()

执行结果

启动服务端：

启动客户端1并发送消息：

启动客户端2并发送消息：

启动客户端3并发送消息：

关闭客户机2：