今日内容

　　1、基于TCP协议（通信循环）

　　2、基于TCP协议（连接循环）

　　3、粘包问题

　　4、模拟SSH实现远程执行命令

服务器端

###############################################################################################

from socket import *
import json
import struct

Sever = socket(AF_INET, SOCK_STREAM)
IP = '192.168.13.131'
PORT = 8084
Sever.bind((IP, PORT))

Sever.listen(5)
while True: #这里说明了循环链接问题的实现方式，在Sver.accept()上面加一个循环可以使得在客户端断开连接后，服务器再次回到这里继续处于阻塞状态，等待下一个客户端请求连接
    conn, address = Sever.accept()
    while True:#这里说明了通信循环问题的实现方式，在data = conn.recv(1024)上面这样服务器可以循环的接收客户端的消息，客户端也是要做相同的循环
        try:
            data = conn.recv(1024)
            num = data.decode('utf-8')[0]
            if num == '1':
                print('从客户端接收到的数据：', data.decode('utf-8'))
　　　　　　　　　#解决粘包问题，在数据前面添加一个报头
                with open(r'%s' % data[1::].decode('utf-8'), mode='rb') as f:
                    msg = b''
                    for i in f.readlines():
                        msg += i
                    file_size = len(msg)
                    header_dic = {
                        'file_name': 'aaa',
                        'file_number': '123456',
                        'file_size': file_size
                    }
                    header_json = json.dumps(header_dic)
                    header = struct.pack('i', len(header_json))
                    conn.send(header)
                    conn.send(header_json.encode('utf-8'))
                    conn.send(msg)
            elif num =='2':
                header = conn.recv(4)
                header_size = struct.unpack('i', header)[0]
                header_json = conn.recv(header_size)
                header_dic = json.loads(header_json)
                total_size = header_dic['file_size']
                print(header_dic)
                file_msg = b''
                recv_size = 0
                with open(r'E:\code\GoodDog\day32\文件上传下载之终极版本\服务器端接收', 'wb') as f:
                    while recv_size < total_size:
                        data = conn.recv(1024)
                        recv_size += len(data)
                        file_msg += data
                        f.write(data)
        except ConnectionResetError:
            break
    conn.close()

################################################################################################

客户端

#####################################################################################################

from socket import *
import json
import struct

PC = socket(AF_INET,SOCK_STREAM)
IP='192.168.13.131'
PORT = 8084
PC.connect((IP,PORT))

while True:
    msg = input('文件地址：').strip()
    if len(msg) == 0:continue
    PC.send(msg.encode('utf-8'))
    if msg[0] == '1':
        header = PC.recv(4)
        header_size = struct.unpack('i', header)[0]
        header_json = PC.recv(header_size)
        header_dic = json.loads(header_json)
        total_size = header_dic['file_size']
        print(header_dic)
        file_msg = b''
        recv_size = 0
        with open(r'E:\code\GoodDog\day32\文件上传下载之终极版本\客户端接收.txt', 'wb') as f:
            while recv_size < total_size:
                data = PC.recv(1024)
                recv_size+=len(data)
                file_msg+=data
                f.write(data)
    elif msg[0] == '2':
        with open(r'E:\code\GoodDog\day32\文件上传下载之终极版本\客户端接收.txt', mode='rb') as f:
            msg = b''
            for i in f.readlines():
                msg += i
            file_size = len(msg)
            print(file_size)
            header_dic = {
                'file_name': 'aaa',
                'file_number': '123456',
                'file_size': file_size
            }
            header_json = json.dumps(header_dic)
            header = struct.pack('i', len(header_json))
            PC.send(header)
            PC.send(header_json.encode('utf-8'))
            PC.send(msg)
            print(msg)

#####################################################################################################

模拟SSH实现远程执行命令

服务器

#######################33##############################################################################

import socket
import subprocess
import struct
Sever = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
ip = '127.0.0.7'
port = 3312
Sever.bind((ip,port))

Sever.listen(2)
while True:
    conn,address = Sever.accept()
    while True:
        try:
            msg = conn.recv(1024)
            obj = subprocess.Popen(r'%s'%msg.decode('utf-8'), shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
            stdout = obj.stdout.read()
            stderr = obj.stderr.read()
            header = struct.pack('i', len(stdout) + len(stderr))
            conn.send(header)
            conn.send(stdout)
            conn.send(stderr)
        except ConnectionResetError:
            break
    conn.close()

Sever.close()

#######################################################################################################

客户端

################################################################################################################

import socket
import struct
PC= socket.socket(socket.AF_INET,socket.SOCK_STREAM)
ip = '127.0.0.7'
port = 3312
PC.connect((ip,port))
while True:
    m = input('请输入：').strip()
    PC.send(m.encode('utf-8'))
    header = PC.recv(4)
    total_size = struct.unpack('i',header)[0]
    cmd_res = b''
    recv_size = 0
    while recv_size < total_size:
        date = PC.recv(1024)
        recv_size+=len(date)
        cmd_res+=date
    print(cmd_res.decode('gbk'))

################################################################################################################