Python : 2 sockets, sending from A to B and from B to A
Question: I've been working on this for 2 days and still I do not manage to get it to
work properly.

I wanted to write an application that uses 2 sockets with a medium in the
middle

This medium is this script that should read from socketA and write to SocketB
and read from SocketB and write to SocketA.

However it seems I can not nail it.

My script when running accepts connections, but it will not allow me to input
something on the telnet screen.

I am using 2 shared lists between the sockets to pass data.

    
    
        #!/usr/bin/env python
        import sys
        import arduinoReadThread
        import arduinoWriteThread
        import socket
        import thread
    
    
    
        bolt = 0
        socketArray=list()
        HOST =""
        HOST2=""
        PORT1 =50115
        PORT2 =50125
    
    
    
        s1=socket.socket(socket.AF_INET, socket.SOCK_STREAM ) #create an INET, STREAMing socket
        s1.bind((HOST,PORT1)) #bind to that port
        s1.listen(2) #listen for user input and accept 1 connection at a time.
        socketArray.append(s1)
        s2=socket.socket(socket.AF_INET, socket.SOCK_STREAM ) #create an INET, STREAMing socket
        s2.bind((HOST2,PORT2)) #bind to that port
        s2.listen(2) #listen for user input and accept 1 connection at a time.
        socketArray.append(s2)
        print "sockets set up"
    
        s1ToWriteList = list()
    
    
        s2ToWriteList = list()
    
    
        def socketFunctionWrite1():
                while(bolt == 0):
                    client, address = s1.accept()
    
                    print "Writing connections"
                    if len(s1ToWriteList) > 0:
                        client.send(s1ToWriteList.pop(0))
    
    
        def socketFunctionRead1():
                while(bolt == 0):
                    client2, address = s2.accept()
    
                    f = client2.recv(1024)
    
                    print "reading connection"
                    s1ToWriteList.append(f)
                    print len(s1ToWriteList)
    
        def socketFunctionWrite2():
                while(bolt == 0):
                    client2, address = s2.accept()
                    print "Writing connections"
                    if len(s2ToWriteList) > 0:
                        client2.send(s2ToWriteList.pop(0))
    
    
    
        def socketFunctionRead2():
                while(bolt == 0):
                    client, address = s1.accept()
                    f = client.recv(1024)
                print "reading connection"
                s2ToWriteList.append(f)
                print len(s2ToWriteList)
    
    
    
    
    def shutDown():
            test = raw_input("Quit ?")
            if(test =="y"):
                bolt = 1
            else:
                shutDown()
    
    def spreadSockets():
    
    
            thread.start_new_thread(socketFunctionRead1,())
            print "launch 1"
            thread.start_new_thread(socketFunctionRead2,())
            print "launch 2"
            thread.start_new_thread(socketFunctionWrite1,())
            print "launch 3"
            thread.start_new_thread(socketFunctionWrite2,())
    
            print "launch 4"
    
    
    
    
    spreadSockets()
    while(True):
            pass
    


Answer: Used your exact code and it worked for me. I think what you might be doing
wrong is telnet'ing to the wrong IP. Dont use 'localhost' or 127.0.0.1, you
need to use the actual (internal) IP of your box.

If on linux, you can see if with `ifconfig -a`, or `ipconfig /all` on windows.

Running your code exactly, no modification (except for removing the 2 unknown
imports at the top):

Launched script:

    
    
    [ 15:01 jon@hozbox.com ~/SO/python ]$ ./sock.py
    sockets set up
    launch 1
    launch 2
    launch 3
    launch 4
    Writing connections
    Writing connections
    ^CTraceback (most recent call last):
      File "./sock.py", line 93, in <module>
        time.sleep(1)
    KeyboardInterrupt
    

Then telnet'd:

    
    
    [ 15:01 jon@hozbox.com ~ ]$ telnet 10.10.1.11 50115
    Trying 10.10.1.11...
    Connected to 10.10.1.11.
    Escape character is '^]'.
    Hello, World!
    Hello 2
    ^]
    telnet> quit
    Connection closed.
    [ 15:02 jon@hozbox.com ~ ]$ telnet 10.10.1.11 50125
    Trying 10.10.1.11...
    Connected to 10.10.1.11.
    Escape character is '^]'.
    Hello 50125!
    Hi!
    ^]
    telnet> quit
    Connection closed.
    [ 15:02 jon@hozbox.com ~ ]$
    

My internal interface config (`inet addr:10.10.1.11`):

    
    
    [ 15:07 jon@hozbox.com ~/SO/python ]$ ifconfig eth0
    eth0      Link encap:Ethernet  HWaddr **:**:**:**:**:**
              inet addr:10.10.1.11  Bcast:10.10.1.255  Mask:255.255.255.0
              ...
    

