Python 3.x--Socket实现简单的ssh和文件下载功能

*****************SSH*********************

---------------服务器端----------------

import os,socket

server = socket.socket()
server.bind(('127.0.0.1',6666))
server.listen()

while True:
    conn, addr = server.accept()
    print("new addr:",addr)
    while True:
        data = conn.recv(1024)
        if not data:
            print("客户端已断开。。。")
            break
        print("执行指令。。。",data)
        res = os.popen(data.decode()).read()   #接受命令，并返回结果
        if len(res)==0:
            res = "cmd has no output..."
        conn.send(str(len(res.encode('utf-8'))).encode('utf-8'))               #发送输出结果的大小
        sleep_recv = conn.recv(1024)
        print("缓冲...",sleep_recv.decode())    #两条send命令可能会出现粘包的情况
        conn.send(res.encode('utf-8'))

server.close()

---------------客户端----------------

import socket

client = socket.socket()
client.connect(('127.0.0.1',6666))

while True:
    cmd = input(">>>:").strip()
    if len(cmd)==0:
        continue
    client.send(cmd.encode('utf-8'))   #发送命令
    res_size = client.recv(1024)          #接收第一个结果：字节长度
    print("命令结果大小：",res_size)
    client.send("已准备好接收命令结果。。。".encode("utf-8"))
    res_size_init = 0
    res_data = b''
    while res_size_init != int(res_size.decode()):
        data = client.recv(1024)   #不一定能接收到正好1024字节的数据
        print(len(data))
        res_size_init += len(data)
        res_data += data
    else:
        print("res_data receive done...",res_size_init)
        print(res_data.decode())

client.close()

运行结果：

 ---------------服务器端----------------

 ---------------客户端----------------

 *****************文件下载*********************

---------------服务器端----------------

import os,socket,hashlib

server = socket.socket()
server.bind(('localhost',6666))
server.listen()

while True:
    conn, addr = server.accept()
    print("new addr:",addr)
    while True:
        data = conn.recv(1024)
        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("utf-8"))   #发送文件大小
            conn.recv(1024)   #等待回复
            for line in f:
                m.update(line)
                conn.send(line)
            print("file md5:",m.hexdigest())
            f.close()
            conn.send(m.hexdigest().encode("utf-8"))   #发送MD5，与上面的“conn.send(line)”可能出现粘包
        print("send done...")

server.close()

---------------客户端----------------

import socket,hashlib

client = socket.socket()
client.connect(('localhost', 6666))

while True:
    cmd = input(">>>:").strip()
    if len(cmd)==0:
        continue
    if cmd.startswith("get"):
        filename = cmd.split()[1]   #获取文件名
        client.send(cmd.encode("utf-8"))
        server_resp_size = client.recv(1024)   #接收文件总的大小
        file_total_size = int(server_resp_size.decode())
        print("file size:", server_resp_size)
        client.send(b"ready to recv file...")
        f = open(filename+".new","wb")
        recv_size = 0
        m = hashlib.md5()
        while recv_size < file_total_size:
            if file_total_size - recv_size > 1024:   #判断最后一次，之前接收大小设置为1024
                size = 1024
            else:                                    #最后一次不足1024，则只接收文件剩余的部分，不包含MD5
                size = file_total_size - recv_size
                print("the last size:",size)
            data = client.recv(size)
            recv_size += len(data)
            f.write(data)
            m.update(data)
        else:
            client_md5 = m.hexdigest()
            print("recv done...")
            print("total size:", file_total_size, "had been received:", recv_size)
            server_md5 = client.recv(1024)
            print("server md5:", client_md5, "server md5:", server_md5.decode())
            f.close()

client.close()

运行结果：