关于socket编程 解析数据包数据python版本

需求：服务端 接收客户端数据存入到本地 数据包格式 包头前4个字节是一个int 解析出来指的是后面跟随的数据的大小 (字节数)

这里我们就要解析包头 存入数据

其实这个思路很简单 就是用socket接收4个字节 解析出int 数据包的大小为x 再去接收x个字节的数据存入到本地就可以了

注意： 由于网络可能会有延迟 recv不一定能完全接收到相应大小的数据 比如 要接收2000个数据 结果只接收了1900个 所以要写个循环判断不断接收到相应字节数为止 包头的那4个字节也要写相同的判断 虽然4个字节漏的概率很小 但是考虑到安全性

下面我给出的是python代码

import socket
import struct

'''
The code is server for receiving a voice data, and save in a file 
'''

#create server

s = socket.socket(socket.AF_INET,socket.SOCK_STREAM,0)  # create socket

HOST = '0.0.0.0' # set host ip 127.0.0.1 will failed so set 0.0.0.0
PORT = 8888 # set host port
s.bind((HOST,PORT)) # bind host and port

s.listen(5) # begin listenging , can conneted max host number is 1

'''
       The following function ensure the packdata can reavice right
       pack_date is received packet data
       pack_date_len is now haved receiving data
       need_packetdata_len is we then need add packet data length for ensuring pack_data complete 
       packet_len is packet head tell us the packet data length
       file for write the voice bit
       
       algorithm：
       if recv data is less packet_len we need, we should add packet we should need until the we received data complete
       
       function use:
       parameter initialize: packet_data_len initialize 0 for while can run, and need_packetdata_len should be packet_len for begining receive
'''
def ReceiveData(packet_data_len,packet_len,need_packetdata_len,file):
    while (packet_data_len < packet_len):
        packet_data = con.recv(need_packetdata_len)
        packet_data_len = len(packet_data) + packet_data_len
        need_packetdata_len = packet_len - packet_data_len
        print("now have receive packet_data len is", packet_data_len)
        file.write(packet_data)

'''
    This function algorithm is same as upper function
    packet_head_len need us to write how long the packet head    
    return the packet len for know the following data length
'''
def ParsingPacketHead(packet_head_len):
    packet_head = con.recv(packet_head_len)
    recv_packet_head_len = len(packet_head)
    while (recv_packet_head_len < packet_head_len):
        need_add_length = packet_head_len - recv_packet_head_len
        packet_head = packet_head + con.recv(need_add_length)
        packet_head_len = len(packet_head)
        print("now packet head len is ",len(packet_head))
    print("break while, packet head len = ",len(packet_head))
    packet_len, = struct.unpack('i', packet_head)  # unpack byte to int
    return packet_len

while(True):
    con, addr = s.accept()  # build client connection, con received new socket object, addr received client ip and  process
    file = open("test.pcm", mode='wb')  # create file for saving binary file
    while(True):
        print('client infomation is ', addr)
        packet_len = ParsingPacketHead(4)
        print("packet_len is ",packet_len)
        ReceiveData(0,packet_len,packet_len,file)

    file.close()
   

 嘿嘿 英文很菜 linux的pycharm中文不太兼容 就随便写的注释 代码很短 还是参考代码为主