基于socket的文件下载

对socket有基本了解后，写了一个简单的文件下载程序

服务端

import socket,os,hashlib
server = socket.socket()
server.bind(('0.0.0.0',9999))
# 监听socket
server.listen()

while True:
    # 接收客户端消息
    conn,addr = server.accept()
    print('new conn:',addr)
    while True:
        print('等待新指令')
        data = conn.recv(1024)
        # 判断数据是否为空
        if not data:
            print('客户端已断开！')
            break
        cmd,filename = data.decode().split()
        print(filename)
        if os.path.isfile(filename):
           f = open(filename,'rb')
           m = hashlib.md5()
           file_size = os.stat(filename).st_size
           conn.send(str(file_size).encode()) #send file size
           conn.recv(1024) #wait for ack
           for line in f:
              m.update(line)
              conn.send(line)#可能会与后面的md5粘包，在client处理
           print('file md5',m.hexdigest())
           f.close()
           conn.send(m.hexdigest().encode())
        print('send done!')

server.close()

客户端

import socket
import hashlib

client = socket.socket()

client.connect(('localhost',9999))

while True:
    cmd = input('>>:').strip()

    if len(cmd)==0:continue
    # 使用get命令
    if cmd.startswith('get'):
       client.send(cmd.encode('utf-8'))
       # 接收服务器文件大小
       file_size = client.recv(1024)
       print('server_resonse',file_size)
       client.send(b'ready to recv file')
       file_total_size = int(file_size.decode())
       received_size = 0
       filename = cmd.split()[1]
       f = open(filename+'.new','wb')
       m=hashlib.md5()

       while received_size < file_total_size:          # 防止粘包，若数据为1025，则剩下的1可能会与md5一起发>送到client，导致md5写入到文件中。
          if file_total_size - received_size > 1024:
             size = 1024
          else:
             size = file_total_size - received_size
          data = client.recv(size)
          received_size += len(data)
          m.update(data)
          f.write(data)
         # print(file_total_size,received_size)
       else:
          new_file_md5 = m.hexdigest()
          print('file recv done',received_size,file_total_size)
          f.close()
       server_file_md5 = client.recv(1024)
       print('server file md5',server_file_md5)
       print('client file md5',new_file_md5 )

client.close()