Develop Reference

Send/Read data to/from a socket SQL Server/Python

Using SQL 2016 & Python 3.7
I currently have two python programs:
A server that receives input from a socket and returns output
A client that sends a prompt to the socket, reads the response and then outputs.
I then have a script in SQL Server that uses xp_cmdshell to run the client and read the results. I'd like to be able to remove the client from the process by using SQL Server to directly access the socket. Unfortunately since you can access SQL Server as a socket, my searches are receiving a high level of noise and not giving me the results I need.
If I upgrade to SQL2017 I can use the internal python option to run the client locally, however upgrading will not be an option for some of our cients and I need a one size fits all solution.
Example Server: SimpleSocket.py:
import socket
from _thread import *
HEADER_LENGTH = 10
def threaded(local_client_socket):
command_header = local_client_socket.recv(HEADER_LENGTH)
command_length = int(command_header.decode("utf-8"))
command = local_client_socket.recv(command_length).decode("utf-8")
if not command:
print('Connection closed by client')
print("Received from client:", command)
reply = f"You sent me '{command}' This is my reply.".encode("utf-8")
reply_header = str(len(reply)).zfill(HEADER_LENGTH).encode("utf-8")
local_client_socket.send(reply_header + reply)
local_client_socket.close()
def open_sockets():
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(("127.0.0.1", 9878))
print("Socket bound to port", 9878)
s.listen(16)
print("Socket is listening")
print("-" * 80)
while True:
client_socket, address = s.accept()
print('Connected to :', address[0], ':', address[1])
start_new_thread(threaded, (client_socket,))
if __name__ == '__main__':
open_sockets()
Example Client: SimpleClient.py
import socket
import sys
HEADER_LENGTH = 10
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect(("127.0.0.1", 9878))
command = "Text I'm sending to server".encode("utf-8")
command_header = str(len(command)).zfill(HEADER_LENGTH).encode("utf-8")
client_socket.send(command_header + command)
reply_header = client_socket.recv(HEADER_LENGTH)
if not len(reply_header):
print("Done")
sys.exit()
reply_length = int(reply_header.decode("utf-8"))
reply = client_socket.recv(reply_length).decode(("utf-8"))
print("Reply from server:", reply)
client_socket.close()
Example SQL Call:
DECLARE #Python_Location NVARCHAR(255) = N'c:\ProgramData\Anaconda3\envs\Search\python.exe'
, #Python_Script NVARCHAR(255) = N'c:\PythonScripts\Search\SimpleClient.py'
, #Command NVARCHAR(255)
SET #Command = N'"' + #Python_Location + N' ' + #Python_Script + '"'
PRINT #Command;
EXECUTE AS USER = 'cmdshell';
EXEC xp_cmdshell #stmt = #Command;
REVERT;
I have used OLE Automation in the past to pull data from a webservice, so was wondering if that may be an option. It's not really an area I know well and my searches haven't turned up anything relevant.
I'd be interested in knowing any options available to me, and all offerings gratefully received. Even if you don't have a full answer, any help may send me in a good direction, or help me structure my search queries to be more relevant. I may even be able to adjust the python code to output the result set to a different format if there's an efficient option.
Many thanks.

Python3 RSPI3 Serial Object Programming

I'm using today for a project a GSM/GPRS RSPI module. My job is to send, with AT commands, files to a FTP server (it's working by a simple program in Python or with putty by sending all AT commands one by one).
Today, to simplify my code, i chose to translate the code in object.
Also, i create my class with all my methods like send SMS, connectGPRS, sendFTP... (these methods do not appear to simplify the code)
But when i'm launching my program, i don't receive my confirm's reply from the module.
When isReady() start, the program send serial command to test the module. But i don't have any reply. My serial port configuration seems like right (debug() return ttyAMA0), and i can control my module by using Putty. But when i'm doing a short circuit with Tx and Rx, i can't see the request from the program on Putty.
Then my program stop in line sys.exit(0) with ser.isReady() returning false.
So my question is : It is possible to use Serial port, like i used it, in object programming ? Or do i make a mistake in my code ?
Regards. (sry btw for my frenchglish)
import serial
print("Reset du module")
resetModem()
time.sleep(5)
ser = ConnexionModule(SERIAL_PORT, 9600, 5)
if not ser.isReady():
print("Failed reboot, maybe a another program connected on serial, or the device isn't lauched")
sys.exit(0)
#debug() is a print function
def debug(text):
if VERBOSE:
print("Debug:---", text)
# This class is in reality in a another file imported in main
class ConnexionModule():
def __init__(self,serial_port,baudrate,timeout):
self.ser = serial.Serial(serial_port, baudrate, timeout)
# Testing if the module is ready to be used
def isReady(self):
# Resetting to defaults
cmd = 'ATZ\r'
# When i send 'ATZ' the module return 'OK'
debug("Cmd: " + cmd)
self.serialwrite(cmd,2)
reply = self.ser.read(self.ser.inWaiting())
reply = reply.decode("utf-8")
time.sleep(8) # Waiting for a reply
debug("Reply: " + reply)
return ("OK" in reply)
def serialwrite(self,cmd,slp):
debug("Sending:")
debug(self.ser.port)
debug(cmd)
self.ser.write(cmd.encode())
time.sleep(slp)
This code working :
import serial
print("Reset du module")
resetModem()
ser = serial.Serial(SERIAL_PORT, baudrate = 9600, timeout = 5)
if not isReady(ser):
print("Fail reboot")
sys.exit(0)
def isReady(pserial):
# Resetting to defaults
cmd = 'ATZ\r'
debug("Cmd: " + cmd)
serialwrite(pserial,cmd,2)
reply = pserial.read(pserial.inWaiting())
reply = reply.decode("utf-8")
time.sleep(8)
debug("Reply: " + reply)
return ("OK" in reply)
def debug(text):
if VERBOSE:
print("Debug:---", text)
def resetModem():
GPIO.setmode(GPIO.BOARD)
GPIO.setup(P_RESET, GPIO.OUT)
GPIO.output(P_RESET, GPIO.LOW)
time.sleep(0.5)
GPIO.output(P_RESET, GPIO.HIGH)
time.sleep(0.5)
GPIO.output(P_RESET, GPIO.LOW)
time.sleep(3)

Client socket not receiving data correctly

I've tried looking about for an answer but I can't seem to find one that answers my specific problem.
Perhaps I don't know how to articulate the problem correctly.
I think I've pinpointed what it is, but the thing is I just don't know how to fix it.
EDIT: I was trying to use two clients on one TCP Socket. Can't do that. I'll have to think of another way. Solved, I guess.
So what I've got is are
1: Two Clients
2: One Server
The objective is this:
Have the server distribute new usernames to all the clients as they connect.
This is what happens when I run the program:
Server: Define Host, and Port, initialize it. Check
Client 1: Connects to the server. Check
Client 1: Once connected, sends a string to the server. Check
Server: Receives a string, checks if the string is in a list is created. If it is: Pass, if it's not, send to everyone the new string. Check
Client 1: [Now waiting to receive data] Recieves data, checks if the string received matches the one it sent. If it does, print("It's one of ours!"), else, make the new string = to Client 2 Username. Check
Client 2: Connects to server: Check
Server: [If it receives a string, prints it.] (Works) Checks if the new string is in the list. [It isn't] So It sends the new username to everyone, and then prints ("Sent to everyone") Check
But, when client 2 receives the string, it prints it. However, client 1 never recives the string.
And when running client one in IDLE, I noticed something went wrong as Client 1 tried to receive the data. (The while loop that the data = s.recv began looping real fast, instead of waiting)
I've asked around in chat, but it seems nobody's around right now. I've tried looking this up but I really can't find an answer. What I suspect is happening is that when my server sends to 'connection' the second time, it somehow overrides the original client connection.
Here's my server code:
from socket import *
import threading
import os
import csv
Username_List = []
host = input("Host: ")
port = input("Port: ")
ss = socket(AF_INET,SOCK_STREAM)
ss.bind((host,int(port)))
ss.listen(2)
while True:
try:
connection,address = ss.accept()
data = connection.recv(1024)
if data:
translated_data = data.decode()
print(translated_data)
if translated_data in Username_List:
pass
else:
Username_List.append(translated_data)
connection.sendall(translated_data.encode())
print("Sent new username to everyone")
except IOError:
connection.close()
print("An exception with a connected user occured")
break
And here is my client code: [The only difference between client 1 and 2 is I changed the username variable]
# Sample Username Client Service Handler.
from socket import *
import threading
import os
import csv
Username = ("Owatch")
host = input("Host: ")
port = input("Port: ")
try:
ss = socket(AF_INET,SOCK_STREAM)
ss.connect((host,int(port)))
except IOError:
print("Aw no man")
ss.send(Username.encode())
while True:
try:
print("Waiting to Recieve Data")
data = ss.recv(1024)
if data:
translated_data = data.decode()
print(translated_data)
if translated_data == Username:
print("It's one of ours!")
else:
Client_Username = translated_data
print (Client_Username)
except Exception as e:
print (vars(e))
If you could please help I'd be grateful.
If you know of an answer to my question that's already been asked, please tell me and I'll remove this post to avoid breaking rules. Thanks!

Right then I started with what you had then changed it till it worked what I've done is created a client class which starts a thread with each connection and adds it to a list of threads (please if I'm doing something horribly wrong smarter people correct me), the thread runs gets some data checks if that's in the list of user names if its not sends out a message to all the clients in the thread list with that name then the thread just chills out. Anyway on to the code.
SERVER!!!
import csv
class client(threading.Thread):
Username_List = []
def __init__(self, conn):
super(client, self).__init__()
self.conn = conn
def run(self):
print "Client thread started"
data = self.conn.recv(1024)
print "Received: {0}".format(data)
if data in client.Username_List:
self.send_msg("Welcome Back!")
else:
for cnt in threadz:
cnt.send_msg(data)
print("Sent new username to everyone")
client.Username_List.append(data)
while True:
# dont need nothing now
pass
def send_msg(self,msg):
self.conn.send(msg)
host = input("Host: ")
port = input("Port: ")
ss = socket() #AF_INET,SOCK_STREAM)
ss.bind((host,int(port)))
print "Server Opening on port: {0}".format(port)
ss.listen(2)
threadz = []
print "Begining Wait for connections"
while True:
try:
connection, address = ss.accept()
print "Got ONE!"
c = client(connection)
print "Recevied connection from:{0} On port:{1}".format(address[0],address[1])
c.start()
threadz.append(c)
print "Client appended to threadz, currently {0} threadz active".format(len(threadz))
except IOError,KeyboardInterrupt:
connection.close()
print("An exception with a connected user occured")
break
The CLIENT:
# Sample Username Client Service Handler.
from socket import *
import threading
import os
import csv
Username = ("ShyGuy")
host = input("Host: ")
port = input("Port: ")
try:
ss = socket() #AF_INET,SOCK_STREAM)
ss.connect((host,int(port))) #I was using ("localhost",1234) for testing
ss.send(Username)
except IOError:
print("Aw no man")
print("Waiting to Recieve Data")
while True:
try:
data = ss.recv(1024)
if data:
translated_data = data.decode()
print(translated_data)
if translated_data == Username:
print"Name: {0} has been registered on server!".format(translated_data)
else:
Client_Username = translated_data
print "New client name received: {0}".format(Client_Username)
except Exception as e:
print (vars(e))
That works on python 2.7 with two clients locally. Needs to use a semaphore to stop the threads printing at the same time as the main server loop prints: http://en.wikipedia.org/wiki/Semaphore_(programming)
This code does nothing graceful with client disconnects, but once you can work with the exceptions that a raised when that happens I'm sure you'll learn some more.

My chat client freezes up after beginning threads

I made a better chat client following help from people:
They told me that if I didn't want to be blocked on .recv when waiting for messages, I would need to use threads, classes, functions, and queues to do so.
So I followed some help a specific person gave me where I created a thread from a class and then defined a function that was supposed to read incoming messages and print them.
I also created a function that allows you to enter stuff to be sent off.
Thing is, when I run the program. Nothing happens.
Can somebody help point out what is wrong? (I've asked questions and researched for 3 days, without getting anywhere, so I did try)
from socket import *
import threading
import json
import select
print("Client Version 3")
HOST = input("Connect to: ")
PORT = int(input("On port: "))
# Create Socket
s = socket(AF_INET,SOCK_STREAM)
s.connect((HOST,PORT))
print("Connected to: ",HOST,)
#-------------------Need 2 threads for handling incoming and outgoing messages--
# 1: Create out_buffer:
Buffer = []
rlist,wlist,xlist = select.select([s],Buffer,[])
class Incoming(threading.Thread):
# made a function a thread
def Incoming_messages():
while True:
for i in rlist:
data = i.recv(1024)
if data:
print(data.decode())
# Now for outgoing data.
def Outgoing():
while True:
user_input=("Your message: ")
if user_input is True:
Buffer += [user_input.encode()]
for i in wlist:
s.sendall(Buffer)
Buffer = []
Thanks for taking a look, thanks also to Tony The Lion for suggesting this

Take a look at this revised version of your code: (in python3.3)
from socket import *
import threading
import json
import select
print("client")
HOST = input("connect to: ")
PORT = int(input("on port: "))
# create the socket
s = socket(AF_INET, SOCK_STREAM)
s.connect((HOST, PORT))
print("connected to:", HOST)
#------------------- need 2 threads for handling incoming and outgoing messages--
# 1: create out_buffer:
out_buffer = []
# for incoming data
def incoming():
rlist,wlist,xlist = select.select([s], out_buffer, [])
while 1:
for i in rlist:
data = i.recv(1024)
if data:
print("\nreceived:", data.decode())
# now for outgoing data
def outgoing():
global out_buffer
while 1:
user_input=input("your message: ")+"\n"
if user_input:
out_buffer += [user_input.encode()]
# for i in wlist:
s.send(out_buffer[0])
out_buffer = []
thread_in = threading.Thread(target=incoming, args=())
thread_out = threading.Thread(target=outgoing, args=())
thread_in.start() # this causes the thread to run
thread_out.start()
thread_in.join() # this waits until the thread has completed
thread_out.join()
in your program you had various problems, namely you need to call the threads; to just define them isn't enough.
you also had forgot the function input() in the line: user_input=input("your message: ")+"\n".
the "select()" function was blocking until you had something to read, so the program didn't arrive to the next sections of the code, so it's better to move it to the reading thread.
the send function in python doesn't accept a list; in python 3.3 it accepts a group of bytes, as returned by the encoded() function, so that part of the code had to be adapted.

socket in python

i tried to do client and server and look what i do
#Server
import socket
Host=''
Port=305
OK=socket.socket()
OK.bind((Host,Port))
OK.listn(1)
OK.accept()
and another one for client
#Client
impot socket
Host='192.168.1.4'
Port=305
OK=socket.socket()
OK.connect((Host,Port))
First thing : for now every thing is ok but i want when client connect to server :
server print "Hello Admin" in client screen
second thing : i want make like input command ! like
COM=raw_input('enter you command system:')
then client enter dir for example then server print the result in client screen

Look here, this is a simple echo server written in Python.
http://ilab.cs.byu.edu/python/socket/echoserver.html

When you create a connection, the story isn't over. Now it's time to send data over the connection. Create a simple "protocol" (*) and use it to transfer data from client to server and/or back. One simple example is a textual protocol of commands separated by newlines - this is similar to what HTTP does.
(*) Protocol: an agreement between two parties on the format of their communication.

I think you might want to do something like this:
client, addr = OK.accept()
client.send("Hello Admin")
And then use
data = client.recv(1024)
to get data from the client.
If you want to get command input from the client, you just need to execute the commands the client sends and send the output back back to the client.
from commands import getoutput
client.send(getoutput(client.recv(1024)))
Thats about the easiest solution possible.

For Client:
import os
import sys
impot socket
Host=raw_input ("Please enter ip : ")
Port=raw_input ("please Enter port :")
OK=socket.socket()
OK.connect((Host,Port))
print " Enter Command")
cmd = raw_input()
os.system(cmd)

I think that your codes has an issue:
you seem to have OK = socket.socket(), but I think it should be:
OK = socket.socket(socket.AF_INET, socket.STREAM), which would help if your making a connection. And your server has a problem: OK.listn(1) should be OK.listen(1). And, don't forget about send() and recv().
#Client
import socket
Host='192.168.1.4'
Port=305
OK=socket.socket(socket.AF_INET, socket.STREAM)
OK.connect((Host,Port))
while True:
com = raw_input("Enter your command: ")
OK.send(com)
data = OK.recv(5000) #Change the buffer if you need to, I have it setup to run 5000
print "Received:\n" + data
which should work for the client
#Server
import socket
import os
Host=''
Port=305
OK=socket.socket(socket.AF_INET, socket.STREAM)
OK.bind((Host,Port))
OK.listen(1)
conn, addr = OK.accept()
while True:
data = conn.recv(2048) #Change the buffer if needed
if data == "":
break
r = os.system(data)
conn.send(str(r)) #Note this will send 0 or 1, 0 = ran, 1 = error
Note: These fixes would work for Windows, I don't know about Unix systems.*