基于UDP/TCP协议的套接字

1.UDP

UDP的数据报协议特点是不粘包，非可靠传输

服务端

import socket
server=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
server.bind(('127.0.0.1',8080))
while True:
    data,client_addr=server.recvfrom(1024)
    print(data)
    print(client_addr)
    server.sendto(data.upper(),client_addr)
server.close()

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客户端

import socket
client=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)

while True:
    msg=input(':').strip()
    client.sendto(msg.encode('utf-8'),('127.0.0.1',8080))
    data,server_addr=client.recvfrom(1024)
    print(data)

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2.TCP

客户端

from socket import *
import struct
import json

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

# 通信循环
while True:
    cmd=input('>>: ').strip()
    if len(cmd) == 0:continue
    client.send(cmd.encode('utf-8'))
    #1. 先收4bytes,解出报头的长度
    header_size=struct.unpack('i',client.recv(4))[0]

    #2. 再接收报头,拿到header_dic
    header_bytes=client.recv(header_size)
    header_json=header_bytes.decode('utf-8')
    header_dic=json.loads(header_json)
    print(header_dic)
    total_size=header_dic['total_size']

    #3. 接收真正的数据
    cmd_res=b''
    recv_size=0
    while recv_size < total_size:
        data=client.recv(1024)
        recv_size+=len(data)
        cmd_res+=data

    print(cmd_res.decode('gbk'))

client.close()

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服务端

# 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 *
import subprocess
import struct
import json

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:
            cmd = conn.recv(1024)  # cmd=b'dir'
            if len(cmd) == 0: break  # 针对linux系统
            obj = subprocess.Popen(cmd.decode('utf-8'),
                                   shell=True,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE
                                   )
            stdout = obj.stdout.read()
            stderr = obj.stderr.read()
            # 1. 先制作报头
            header_dic = {
                'filename': 'a.txt',
                'md5': 'asdfasdf123123x1',
                'total_size': len(stdout) + len(stderr)
            }
            header_json = json.dumps(header_dic)
            header_bytes = header_json.encode('utf-8')

            # 2. 先发送4个bytes(包含报头的长度)
            conn.send(struct.pack('i', len(header_bytes)))
            # 3  再发送报头
            conn.send(header_bytes)

            # 4. 最后发送真实的数据
            conn.send(stdout)
            conn.send(stderr)
        except ConnectionResetError:
            break

    conn.close()

server.close()

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3.socketserver模块的使用

TCP的服务端

import socketserver

class MyTCPhandler(socketserver.BaseRequestHandler):
    def handle(self):
        while True:
            try:
                data=self.request.recv(1024)
                if len(data)==0:break
                print('收到客户端信息：',data)
                self.request.send(data.upper())
            except ConnectionResetError:
                break
        self.request.close()

if __name__ == '__main__':
    server=socketserver.ThreadingTCPServer(('127.0.0.1',8080),MyTCPhandler)
    server.serve_forever()

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UDP的客户端

import socketserver
class MyUdphandler(socketserver.BaseRequestHandler):
    def handle(self):
        data,sock=self.request
        print(data)
        sock.sendto(data.upper(),self.client_address)
if __name__ == '__main__':
    server=socketserver.ThreadingUDPServer(('127.0.0.1',8080),MyUdphandler)
    server.serve_forever()

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