Socket傳輸簡單的信息以及粘包問題的解決

　　1、簡單的socket程序——傳輸簡短文字：

# -*- coding: utf-8  -*-
# -*- Author: WangHW -*-
import socket

whw_client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
whw_client.connect(('127.0.0.1',9001))
while 1:
    cmd = input('>>>:').strip()
    if not cmd:
        continue
    whw_client.send(cmd.encode('utf-8'))
    recv_data = whw_client.recv(1024)
    data = recv_data.decode('utf-8')
    print('server data:',data)

client

# -*- coding: utf-8  -*-
# -*- Author: WangHW -*-
import socket

whw_server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
whw_server.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
whw_server.bind(('127.0.0.1',9001))
whw_server.listen(5)
print('listening......')
conn,addr = whw_server.accept()
#通訊循環
while 1:
    try:
        recv_data = conn.recv(1024)
        data = recv_data.decode('utf-8')
        print('client data:',data)
        conn.send(data.swapcase().encode('utf-8'))
    except ConnectionResetError:
        break
conn.close()

server

　　演示以下：

2、模擬SSH命令——解決粘包問題版：

　　關於粘包問題的解決方案：

　　在服務器端，因爲解析出來的命令結果很是多，因此咱們在發送結果以前須要先給客戶端發送一個「報文」，這個報文保存着具體的命令結果的信息——其中關鍵的信息就是結果的長度，客戶端只有知道這個結果的長度後，才能制定相應的接收規則：

# -*- coding: utf-8  -*-
# -*- Author: WangHW -*-
import socket
import json
import struct

whw_client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
whw_client.connect(('127.0.0.1',9000))
while 1:
    try:
        cmd = input('>>>:').strip()
        if not cmd:
            continue
        #發命令
        whw_client.send(cmd.encode('utf-8'))
        #1.收報頭長度
        obj = whw_client.recv(10)
        #注意structunpack出來的[0]值爲長度信息
        header_size = struct.unpack('i',obj)[0]
        #2.收報頭——根據報頭長度來收
        header_bytes = whw_client.recv(header_size)
        #3.從報頭中解析出'total_size'
        header_json = header_bytes.decode('utf-8')
        header_dic = json.loads(header_json)
        total_size = header_dic['total_size']
        #根據total_size開始接收真實的數據
        recv_size = 0
        recv_data = b''
        while recv_size < total_size:
            res = whw_client.recv(1024)
            recv_data += res
            recv_size += len(res)
        print('命令結果:\n',recv_data.decode('gbk'))
    except Exception as e:
        whw_client.close()

client

# -*- coding: utf-8  -*-
# -*- Author: WangHW -*-
import socket
import subprocess
import json
import struct

whw_server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
whw_server.bind(('127.0.0.1',9000))
whw_server.listen(5)
print('Listening......')
conn,addr = whw_server.accept()
while 1:
    try:
        #收命令
        cmd_recv = conn.recv(1024).decode('utf-8')
        #解析命令
        obj = subprocess.Popen(cmd_recv,shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
        stdout = obj.stdout.read()
        stderr = obj.stderr.read()
        #將命令返回給客戶端
        #1.製做固定報頭——注意報頭裏面要包含數據的總長度！
        header_dic = {'filename':'whw','total_size':len(stdout)+len(stderr)}
        header_json = json.dumps(header_dic)
        header_bytes = header_json.encode('utf-8')
        #2.發送報頭長度——struct:把數字打成固定長度
        conn.send(struct.pack('i',len(header_bytes)))
        #3.發送報頭
        conn.send(header_bytes)
        #4.發送真實數據
        conn.send(stdout)
        conn.send(stderr)
    except ConnectionResetError:
        break

conn.close()

server

　　演示以下：