经测试可以勉强使用的netcat模拟器，python3代码，书上原来是python2的 做了一些小修改

import sys

import socket

import getopt

import threading

import subprocess

listen = False

command = False

upload = False

excute = ""

target = ""

upload_destination = ""

port = 0

def usage():
print("BHP net tool")
print("Usage:netcat.py -t -target_host -p port")
print("-l  --listen  -listen on [host]:[port] for incoming connection   ")
print("-e  --excute=file_to_run  -excute the given file upon receiving a connection")
print("-c --command  -initialize a command shell")
print("-u  --upload=destination  -upon receiving connection upload a file and write to [destination]")
print("Example:")
print("netcat.py -t 192.168.0.1 -p 5555 -l -c")
print("netcat.py -t 192.168.0.1 -p 5555 -l -u=c:\\target.exe")
print("netcat.py -t 192.168.0.1 -p 5555 -l -e=\"cat /etc/passwd\"")
print("echo 'ABCDEFGHI' | ./netcat.py -t 192.168.11.12 -p 135")
sys.exit(0)

def main():
global listen
global excute
global command
global upload_destination
global target
global port

if not len(sys.argv[1:]):
usage()

try:
opts,args = getopt.getopt(sys.argv[1:],"hle:t:p:cu",["help","listen","execute","target","port","command","upload"])
except getopt.GetoptError as err:
print(str(err))
usage()

for o,a in opts:
if o in ("-h","--help"):
usage()
elif o in ("-l","--listen"):
listen = True
elif o in ("-e","--excute"):
excute = a
elif o in ("-c","--command"):
command = True
elif o in ("-u","--upload"):
upload_destination = a
elif o in ("-t","--target"):
target = a
elif o in ("-p","--port"):
port = int(a)

else:
print("Unhandled option")
usage()

if not listen and len(target) and port>0:
bufer = sys.stdin.read()
client_sender(bufer)
if listen:
server_loop()

def client_sender(bufer):
print("into client_sender")
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
try:
client.connect((target,port))
if len(bufer):
client.send(bufer.encode())

while True:
recv_len = 1
response = ""
print("waiting for message return")
while recv_len:
data = client.recv(4096).decode('gb2312')
recv_len = len(data)
response += data
print("receive length")
if recv_len<4096:
break
print(response)
bufer = input("")
bufer += "\n"

client.send(bufer.encode())

except Exception as e:
print(e)
print("Exception! Exiting.")
client.close()

def server_loop():
print("into server_loop")
global target
if not len(target):
target = "0.0.0.0"
server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
print(target)
print(port)
server.bind((target,port))
server.listen(5)
while True:
client_socket,addr = server.accept()
client_thread = threading.Thread(target = client_handler,args=(client_socket,))
client_thread.start()

def run_command(command):
print("into run_command")
command = command.rstrip()
try:
output = subprocess.check_output(command,stderr=subprocess.STDOUT,shell=True)
except:
output = "Failed to excute command.\r\n"
return output

def client_handler(client_socket):
global upload
global excute
global command

print("into client_handler")
if len(upload_destination):
file_buffer = ""

while True:
data = client_socket.recv(1024)
if not data:
break
else :
file_buffer += data
try:
file_descriptor = open(upload_
4000
destination,"wb")
file_descriptor.write(file_buffer)
file_descriptor.close()

client_socket.send(("Successfully saved file to "+upload_destination).encode())
except:
client_socket.send(("Failed saved file to "+upload_destination).encode())

if len(excute):
output = run_command(excute)

client_socket.send(output)

if command:
while True:
client_socket.send("<netcat:#>".encode())
# print("send netcat")
cmd_buffer = ""
while "\n" not in cmd_buffer:
cmd_buffer += client_socket.recv(1024).decode()
print(cmd_buffer)
response = run_command(cmd_buffer)
print(response)
client_socket.send(response)

main()