Python学习笔记1：简单实现ssh客户端和服务端

实现基于python 3.6。

server端：

__author__ = "PyDev2018"

import socket,os
server = socket.socket()
server.bind(('127.0.0.1',10090))

server.listen()

while True:
    conn,addr = server.accept()
    print("New conn: ",addr)
    while True:
        data = conn.recv(1024)
        if not data:
            print("客户端已断开！")
            break
        print("执行指令：",data)
        cmd_res = os.popen(data.decode('utf-8')).read()
        print("命令返回值size：",len(cmd_res)) #这里数据有可能为空
        if len(cmd_res) == 0:
            cmd_res = "cmd has no output!"
        conn.send(str(len(cmd_res.encode('utf-8'))).encode("utf-8"))  #先把回显的大小发给客户端,回显可能有中文，先decode一次，防止len错误
        conn.send(cmd_res.encode('utf-8'))
        print("命令返回值发送完毕！")
server.close()

client端：

__author__ = 'PyDev2018'

import socket
client = socket.socket()

client.connect(('localhost',10090))

while True:
    cmd = input(">>>:").strip()
    if len(cmd) == 0:continue
    client.send(cmd.encode("utf-8"))
    cmd_res_size = client.recv(1024) #接受返回值的大小
    print("命令返回值的大小为：",cmd_res_size)
    received_size = 0 #已经接收到的数据大小
    received_data = b'' 
    while received_size < int(cmd_res_size.decode()):
        data = client.recv(1024)
        received_size += len(data) #这里记录总接收的数据
        received_data += data
        
    else:
        print(received_data.decode("utf-8"))
        print("接收返回值ok!",received_size)
        

client.close()