scoket模块 粘包问题 tcp协议特点

1 用打电话的流程快速描述socket通信
2 服务端和客户端加上基于一次连接的循环通信
3 客户端发送发空，卡主，证明是从那一个位置卡的

服务端：
from socket import *

phone =socket(AF_INET，SOCK_STREAM)
phone.bind((‘127.0.0.1‘,8081))
phone.listen(5)

conn,addr =phone.accept()
while True:
    data =conn.recv(1024)
    print(‘server===>‘)
    print(data)
    conn.send(data.upper())
conn.close()
phone.close()

客户端：
from socket import *

phone=socket(AF_INET,SOCK_STREAM)
phone.connect((‘127.0.0.1‘,8081))

while True:
    msg=input(‘>>: ‘).strip()
    phone.send(msg.encode(‘utf-8‘))
    print(‘client===>‘)
    data=phone.recv(1024)
    print(data)

说明卡的原有：缓冲区为空recv就卡主，引出原理图

简单演示udp
服务端
from socket import *
phone =socket(AF_INET,SOCK_DGRAM)
phone.bind((‘127.0.0.1‘,8082))

while True:
    msg,addr =phone.recvfrom(1024)
    phone.sendto(msg.upper(),addr)


# 客户端
from socket import *
phone =socket(AF_INET,SOCK_DGRAM)
while True:
    msg=input(‘>>: ‘)
    phone.sendto(msg.encode(‘utf-8‘),(‘127.0.0.1‘,8082))
    msg,addr =phone.recvfrom(1024)
    print(msg)
  
udp客户端可以并发演示
udp客户端可以输入为空演示

import socket

server = socket.socket() #买手机
server.bind((‘127.0.0.1‘,8080)) #插手机卡  bind（（ip,port))

server.listen(5)  #开机  半整数池

conn , addr =server.accept()  #待机等待接电话
print(conn)  #双向通道
print(addr)  #地址  (‘127.0.0.1‘, 52942)

data = conn.recv(1024)  #接听别人说话 只接收1024个字节 bytes

print(data)   #b‘hello how much?‘
conn.send(b‘hello big baby!‘)  #跟别人说话

conn.close()   #关闭通信连接
server.close()  #关闭服务端

import socket

#t套接字对象
client = socket.socket()

client.connect((‘127.0.0.1‘,8080))  #找服务器 拨电话

client.send(b‘hello how much?‘)  #给服务器发信息
data = client.recv(1024)    #接收服务器发来的信息
print(data)

client.close()   #关闭客户端

import socket
ip_port=(‘127.0.0.1‘,8081)#电话卡
BUFSIZE=1024
s=socket.socket(socket.AF_INET,socket.SOCK_STREAM) #买手机
s.bind(ip_port) #手机插卡
s.listen(5)     #手机待机


while True:                         #新增接收链接循环,可以不停的接电话
    conn,addr=s.accept()            #手机接电话
    # print(conn)
    # print(addr)
    print(‘接到来自%s的电话‘ %addr[0])
    while True:                         #新增通信循环,可以不断的通信,收发消息
        msg=conn.recv(BUFSIZE)             #听消息,听话

        # if len(msg) == 0:break        #如果不加,那么正在链接的客户端突然断开,recv便不再阻塞,死循环发生

        print(msg,type(msg))

        conn.send(msg.upper())          #发消息,说话

    conn.close()                    #挂电话

s.close()                       #手机关机

import socket
ip_port=(‘127.0.0.1‘,8081)
BUFSIZE=1024
s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)

s.connect_ex(ip_port)           #拨电话

while True:                             #新增通信循环,客户端可以不断发收消息
    msg=input(‘>>: ‘).strip()
    if len(msg) == 0:continue
    s.send(msg.encode(‘utf-8‘))         #发消息,说话(只能发送字节类型)

    feedback=s.recv(BUFSIZE)                           #收消息,听话
    print(feedback.decode(‘utf-8‘))

s.close()                                       #挂电话

import socket

server = socket.socket()
server.bind((‘127.0.0.1‘,8808))

server.listen(5)  #半连接池 等待连接的最大的客户端数

conn,addr = server.accept()

# data = conn.recv(1024)
# print(data)
 #b‘hellohellohello‘ 接收的小于1024的 所有的客户端发来的信息

data = conn.recv(4)
print(data)
  #b‘hell‘

data = conn.recv(5)
print(data)
 #b‘ohell‘   #会先接收上次没接收完的信息

data = conn.recv(5)
print(data)
 #b‘ohell‘   #会先接收上次没接收完的信息
conn.close()

server.close()

import socket

client = socket.socket()

client.connect((‘127.0.0.1‘,8808))


client.send(b‘hello‘)
client.send(b‘hello‘)
client.send(b‘hello‘)
#tcp协议的优化特点 发送数据量小的间隔时间短 会一起发送
#会将数据量比较小的并且时间间隔比较短的数据一次性打包发送给接收端

client.close()

import socket
import subprocess
import struct
import json

server =socket.socket()
server.bind((‘127.0.0.1‘,8081))
server.listen(5) #半连接池

while True:
    conn ,addr =server.accept()  #等待电话
    while True:
        try:
            data = conn.recv(1024).decode(‘utf-8‘)
            if len(data) == 0:break
            obj = subprocess.Popen(data,shell=True,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE)
            stdout = obj.stdout.read()
            stderr = obj.stderr.read()
            print(len(stderr+stdout))

            header_dic = {
                ‘filename‘:‘cls.av‘,
                ‘len‘:len(stdout+stderr)
            }

            header_bytes = json.dumps(header_dic).encode(‘utf-8‘)

            #制作报头
            header = struct.pack(‘i‘,len(header_bytes))

            conn.send(header)
            conn.send(header_bytes)

            conn.send(stdout)
            conn.send(stderr)
                #conn.send(stdout+stderr) 字符串拼接 从新拷贝一份占内存
                #  和单独发也是一样的 间隔时间短的接收到的也是一起的
        except  ConnectionResetError:
            break

    conn.close()
server.close()

import socket,struct,json

client = socket.socket()

client.connect((‘127.0.0.1‘,8081))

while True:
    msg = input(‘>>>: ‘).encode(‘utf-8‘)
    if len(msg)==0:continue

    client.send(msg)

    header = client.recv(4)  #接收字典打包后的4个长度的字节 精确接收
    print(header,‘这是报头的长度‘)

    head_len = struct.unpack(‘i‘,header)[0] #对这个头进行解包，获取原来的字典的字节数长度
    print(head_len,‘这是字典的字节数‘)

    head_dic =json.loads(client.recv(head_len).decode(‘utf-8‘))
               # 反序列化       接收字典的长度(精确接收）解码
                #得到字典
    print(head_dic,‘这是字典‘)
    #对需要接受的数据 进行循环接收
    total_size = head_dic[‘len‘]
    recv_size=0
    res=b‘‘
    while recv_size < total_size: #字符
        data = client.recv(1024)  #每次接收到的信息
        res +=data
        recv_size +=len(data)
    print(res.decode(‘gbk‘))

client.close()

import socket
server=socket.socket(type=socket.SOCK_DGRAM)
server.bind((‘127.0.0.1‘,8080))

while True:
    msg,addr =server.recvfrom(1024)
    print(addr,msg.decode(‘utf-8‘))
    data=input(‘服务端回复：‘).encode(‘utf-8‘)
    server.sendto(data,addr)

import socket

client =socket.socket(type=socket.SOCK_DGRAM)

server_addr =(‘127.0.0.1‘,8080)

while True:
    msg = input(‘输入消息：‘)
    msg = ‘客服端1的消息:%s‘ % msg
    client.sendto(msg.encode(‘utf-8‘),server_addr)
    data,addr =client.recvfrom(1024)
    print(data.decode(‘utf-8‘))

import socket

client =socket.socket(type=socket.SOCK_DGRAM)

server_addr =(‘127.0.0.1‘,8080)

while True:
    msg = input(‘输入消息：‘)
    msg = ‘客服端2的消息:%s‘ % msg
    client.sendto(msg.encode(‘utf-8‘),server_addr)
    data,addr =client.recvfrom(1024)
    print(data.decode(‘utf-8‘))

import socket

client =socket.socket(type=socket.SOCK_DGRAM)

server_addr =(‘127.0.0.1‘,8080)

while True:
    msg=input(‘输入消息：‘)
    msg=‘客服端3的消息：%s‘%msg
    client.sendto(msg.encode(‘utf-8‘),server_addr)
    data,addr =client.recvfrom(1024)
    print(data.decode(‘utf-8‘))

import socket
import subprocess
import struct

‘‘‘
服务端必备三要素：
    1 要有固定的ip和port
    2 要能24小时提供服务
    3 能承受高并发
        并发：看上去像同时进行
‘‘‘
server=socket.socket()
server.bind((‘127.0.0.1‘,8080))
server.listen(5)

while True:
    conn,addr =server.accept()
    while True:
        try:
            cmd =conn.recv(1024).decode(‘utf-8‘)
            if len(cmd)==0:break #针对linux mac系统
            obj=subprocess.Popen(cmd,shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)

            stdout=obj.stdout.read()
            stderr=obj.stderr.read()

            #制作固定报头
            header=struct.pack(‘i‘,len(stderr+stdout))
            #发送固定长度的报头
            conn.send(header)

            #发送真是数据
            conn.send(stdout)
            conn.send(stderr)
        except ConnectionResetError:
            break
    conn.close()

import socket
import struct

client =socket.socket()
client.connect((‘127.0.0.1‘,8080))

while True:
    cmd =input(‘>>:‘).encode(‘utf-8‘)
    if len(cmd)==0:continue
    client.send(cmd)

    header=client.recv(4)
    #解析报头获取真是数据的长度
    total_size=struct.unpack(‘i‘,header)[0]
    recv_size=0
    data=b""
    while recv_size<total_size:
        res=client.recv(1024)
        recv_size+=len(res)
        data+=res

    print(data.decode(‘gbk‘))

import socket


client =socket.socket()
client.connect((‘127.0.0.1‘,8080))

while True:
    client.send(b‘hello world‘)
    data= client.recv(1024)

    print(data)

import socketserver


class MyBaby(socketserver.BaseRequestHandler):
    def handle(self):
        #通信循环
        while True:
            #self.request相当于你的conn通信对象
            data= self.request.recv(1024) #收消息
            print(data)
            self.request.send(data.upper())





if __name__ == ‘__main__‘:          #通道循环
    server = socketserver.ThreadingTCPServer((‘127.0.0.1‘,8080),MyBaby)
    server.serve_forever()

import  socket
import time

client =socket.socket(type=socket.SOCK_DGRAM)
server_addr=(‘127.0.0.1‘,8080)

while True:
    client.sendto(b‘hello world‘,server_addr)
    data,addr =client.recvfrom(1024)
    print(data,addr)
    time.sleep(1)

import socketserver

class MyBaby(socketserver.BaseRequestHandler):
    def handle(self):
        #通讯循环
        while True:
            #self.request 相当于conn通讯对象
            data,sock =self.request #收消息
            print(data)
            print(sock)
            sock.sendto(data.upper(),self.client_address)  #self.client_address 客户端地址

if __name__ == ‘__main__‘:
    server=socketserver.ThreadingUDPServer((‘127.0.0.1‘,8080),MyBaby)
    server.serve_forever()

import socket
import struct
import json

server = socket.socket()
server.bind((‘127.0.0.1‘, 8080))
server.listen(5)

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

    while True:
        try:
            # 接收报头
            header = conn.recv(4)
            # 解析报头获取字典长度
            header_len = struct.unpack(‘i‘, header)[0]

            # 接收字典
            header_bytes = conn.recv(header_len)
            header_dic = json.loads(header_bytes.decode(‘utf-8‘))
            print(header_dic)

            # 循环接收文件存储到本地
            file_size = header_dic.get(‘file_size‘)
            file_name = header_dic.get(‘file_name‘)

            recv_size = 0
            # 文件操作
            with open(file_name, ‘wb‘)as f:
                # 循环接收文件
                while recv_size < file_size:
                    data = conn.recv(1024)
                    f.write(data)
                    recv_size += len(data)
            print(header_dic.get(‘msg‘))
        except ConnectionResetError:
            break
    conn.close()

import socket
import os
import json
import struct

client = socket.socket()
client.connect((‘127.0.0.1‘, 8080))

# 文件大小
file_size = os.path.getsize(r‘E:\代码存放位置\第八周\莫文蔚-偷情.mp3‘)

# 文件名字
file_name = ‘歌曲名：偷情- 歌手：莫文蔚.mp3‘

# 定义一个字典
d = {
    "file_name": file_name,
    "file_size": file_size,
    "msg": ‘注意身体哦‘

}

data_bytes = json.dumps(d).encode(‘utf-8‘)

# 制作字典的报头
header = struct.pack(‘i‘, len(data_bytes))

# 发送报头
client.send(header)

# 发送字典
client.send(data_bytes)

# 发送真实数据
with open(r‘E:\代码存放位置\第八周\莫文蔚-偷情.mp3‘, ‘rb‘)as f:
    for line in f:
        client.send(line)