套接字通信底层原理

套接字通信底层原理
由应用程序内存拷贝到操作系统，操作系统遵循TCP协议向对方去发，对方接收到并发送信号

from socket import *

client = socket(AF_INET, SOCK_STREAM)
client.connect(('127.0.0.1', 8081))

# 通信循环
while True:
    msg=input('>>: ').strip() #msg=''
    if len(msg) == 0:continue
    client.send(msg.encode('utf-8')) #client.send(b'')
    print('has send')
    data=client.recv(1024)
    print('has recv')
    print(data)

client.close()

# 服务端必须满足至少三点:
# 1. 绑定一个固定的ip和port
# 2. 一直对外提供服务,稳定运行
# 3. 能够支持并发
from socket import *

server = socket(AF_INET, SOCK_STREAM)
server.bind(('127.0.0.1', 8081))
server.listen(5)

# 链接循环
while True:
    conn, client_addr = server.accept()
    print(client_addr)

    # 通信循环
    while True:
        try:
            data = conn.recv(1024)
            if len(data) == 0: break  # 针对linux系统
            print('-->收到客户端的消息: ', data)
            conn.send(data.upper())
        except ConnectionResetError:
            break

    conn.close()

server.close()