python - Python套接字：可以发送字符串但不能发送“输出”（从套接字断开）

Question

我是一名 Python 初学者，我正在基于中央服务器和两个客户端（一个发送命令，另一个接收命令并发送输出）编写这个远程 shell。

操作系统是 Windows 10 64 位，Python 是 3.7。

如果我将字符串或简单变量从一个发送到另一个是可以的，但是当例如我想发送 file.read() 或子进程的输出时，我与中央服务器断开连接：

你已经与服务器断开连接

我在这里缺少什么？

服务器代码：

import socket
import threading

#Variables for holding information about connections
connections = []
total_connections = 0

#Client class, new instance created for each connected client
#Each instance has the socket and address that is associated with items
#Along with an assigned ID and a name chosen by the client
class Client(threading.Thread):
    def __init__(self, socket, address, id, name, signal):
        threading.Thread.__init__(self)
        self.socket = socket
        self.address = address
        self.id = id
        self.name = name
        self.signal = signal

    def __str__(self):
        return str(self.id) + " " + str(self.address)

    #Attempt to get data from client
    #If unable to, assume client has disconnected and remove him from server data
    #If able to and we get data back, print it in the server and send it back to every
    #client aside from the client that has sent it
    #.decode is used to convert the byte data into a printable string
    def run(self):
        while self.signal:
            try:
                data = self.socket.recv(1024)
            except:
                print("Client " + str(self.address) + " has disconnected")
                self.signal = False
                connections.remove(self)
                break
            if data != "":
                print("ID " + str(self.id) + ": " + str(data.decode("utf-8")))
                for client in connections:
                    if client.id != self.id:
                        client.socket.sendall(data)

#Wait for new connections
def newConnections(socket):
    while True:
        sock, address = socket.accept()
        global total_connections
        connections.append(Client(sock, address, total_connections, "Name", True))
        connections[len(connections) - 1].start()
        print("New connection at ID " + str(connections[len(connections) - 1]))
        total_connections += 1

def main():
    #Get host and port
    host = "192.168.1.240"
    port = 9876

    #Create new server socket
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind((host, port))
    sock.listen(5)

    #Create new thread to wait for connections
    newConnectionsThread = threading.Thread(target = newConnections, args = (sock,))
    newConnectionsThread.start()

main()

执行命令并断开连接的客户端代码有一个注释，它断开连接，它与 file.read() 的输出相同

import socket
import threading
import sys
import requests
import subprocess
import time

hisID = "Server:"

def telegram_bot_sendtext(bot_message):

    bot_token = 'xxxxxx'
    bot_chatID = 'xxxxxx'
    send_text = 'https://api.telegram.org/bot' + bot_token + '/sendMessage?chat_id=' + bot_chatID + '&parse_mode=Markdown&text=' + bot_message

    response = requests.get(send_text)

    return response.json()

#Wait for incoming data from server
#.decode is used to turn the message in bytes to a string
def receive(socket, signal):
    while signal:
        try:
            data = socket.recv(1024)
            command = str(data.decode("utf-8"))
            print(command)
            if command == "oof":
                sock.sendall(str.encode("YOU TOLD ME TO oof?"))
                telegram_bot_sendtext("oof")
            elif command == "command": 
                out = subprocess.check_output("dir", shell=True)
                sock.sendall(str.encode(out)) #HERE I GOT DISCONNECTED
            else:
                sock.sendall(str.encode("Command not recognized"))
        except:
            print("You have been disconnected from the server")
            signal = False
            break

#Get host and port
host = "192.168.1.240"
port = 9876

#Attempt connection to server
try:
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((host, port))
except:
    print("Could not make a connection to the server")
    input("Press enter to quit")
    sys.exit(0)

#Create new thread to wait for data
receiveThread = threading.Thread(target = receive, args = (sock, True))
receiveThread.start()

#Send data to server
#str.encode is used to turn the string message into bytes so it can be sent across the network
while True:
    try:
        input()
    except (KeyboardInterrupt, SystemExit):
        sock.close()
        sys.exit()

发送命令的客户端代码

import socket
import threading
import sys
hisID = "Client:"
#Wait for incoming data from server
#.decode is used to turn the message in bytes to a string
def receive(socket, signal):
    while signal:
        try:
            data = socket.recv(1024)
            command = str(data.decode("utf-8"))
            print(hisID + ">" + command )
        except:
            print("You have been disconnected from the server")
            signal = False
            break

#Get host and port
host = "192.168.1.240"
port = 9876

#Attempt connection to server
try:
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((host, port))
except:
    print("Could not make a connection to the server")
    input("Press enter to quit")
    sys.exit(0)

#Create new thread to wait for data
receiveThread = threading.Thread(target = receive, args = (sock, True))
receiveThread.start()

#Send data to server
#str.encode is used to turn the string message into bytes so it can be sent across the network
while True:
    message = input(":>")
    sock.sendall(str.encode(message))

标签： pythonpython-3.xwindowssocketspython-requests

Answer 1

代码中的裸露except隐藏了编码错误。理想情况下，只捕获您期望的错误（套接字错误OSError用作基类），因此不会隐藏意外错误。您也可以将异常原因添加到错误消息中。

except OSError as e:
    print(f"You have been disconnected from the server: {e}")

通过此更改，您将清楚地看到问题：

Traceback (most recent call last):
  File "C:\Python36\lib\threading.py", line 916, in _bootstrap_inner
    self.run()
  File "C:\Python36\lib\threading.py", line 864, in run
    self._target(*self._args, **self._kwargs)
  File "C:\client.py", line 34, in receive
    sock.sendall(str.encode(out)) #HERE I GOT DISCONNECTED
TypeError: descriptor 'encode' requires a 'str' object but received a 'bytes'

错误修复是使用sock.sendall(out).