Python Forum

I have a client-server system set up on two Raspberry Pi's on the same network. When I run the echo program below (client sends the server a message, server sends the message back, client prints received message) I get no errors and everything works great. When I run the "GPS" program below (just sends a message to client) the client recieves and prints the messaage no problem but the server gives me the error

BrokenPipeError: [Errno 32] Broken pipe

and exits the program. The only thing I can think of causing this would be the buffer size on the client side message-receiving code since everything else is pretty much the same but I'm not sure how to approach this. Anyone have any solutions?

Echo Server:

# Echo server program
import socket
import sys

# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Bind the socket to the port
server_address = ('ip address', 50007)
print ('starting up on %s port %s' % server_address)
sock.bind(server_address)

# Listen for incoming connections
sock.listen(1)

while True:
    # Wait for a connection
    print('waiting for a connection')
    connection, client_address = sock.accept()

    try:
        print ('connection from', client_address)

        # Receive the data in small chunks and retransmit it
        while True:
            chunk = 1024
            data = connection.recv(chunk)
            dec_data = data.decode('utf-8')
            print('received "%s"' % dec_data)
            if dec_data:
                print('sending data back to the client')
                connection.sendall(data)
            else:
                print('no more data from', client_address)
                break

    finally:
        # Clean up the connection
        connection.close()

Echo Client:

# Echo client program
import socket
import sys

# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Connect the socket to the port where the server is listening
server_address = ('ip address', 50007)
print('connecting to %s port %s' % server_address)
sock.connect(server_address)

try:
    # Send data
    message = ('This is the message.  It will be repeated.')
    enc_mes = message.encode('utf-8')
    print('sending "%s"' % message)
    sock.sendall(enc_mes)

    # Look for the response
    amount_received = 0
    amount_expected = len(message)

    while amount_received < amount_expected:
        chunk = 1024
        data = sock.recv(chunk)
        amount_received += len(data)
        dec_data = data.decode('utf-8')
        print('received "%s"' % dec_data)

finally:
    print('closing socket')
    sock.close()

GPS Server:

# GPS server program
import socket
import sys

# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Bind the socket to the port
server_address = ('ip address', 50007)
print ('starting up on %s port %s' % server_address)
sock.bind(server_address)

# Listen for incoming connections
sock.listen(1)

while True:
    # Wait for a connection
    print('waiting for a connection')
    connection, client_address = sock.accept()

    try:
        print ('connection from', client_address)

        # Message transmission
        while True:
            # Send GPS data
            gps_data = ('Pretend GPS Data').encode('utf-8')
            connection.sendall(gps_data)

    finally:
        # Clean up the connection
        connection.close()

GPS Client:

# GPS client program
import socket
import sys

# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Connect the socket to the port where the server is listening
server_address = ('ip address', 50007)
print('connecting to %s port %s' % server_address)
sock.connect(server_address)

try:
    # Look for the response
    bufsize = 2048
    data = sock.recv(bufsize)
    dec_data = data.decode('utf-8')
    print('received "%s"' % dec_data)

finally:
    print('closing socket')
    sock.close()

(Nov-15-2018, 09:22 PM)Pflaumboy Wrote: [ -> ]

        while True:
            # Send GPS data
            gps_data = ('Pretend GPS Data').encode('utf-8')
            connection.sendall(gps_data)

I don't know a lot about sockets, but sending an infinite amount of data sounds like something that should be throwing errors.

maybe giving a time delay will fix the issue

this happens when the receiving end of the pipe closes the pipe then the sending end writes a buffer to the pipe. handle or ignore that exception. i usually just ignore it (pass). this can happen on stdout or stderr if the scripts are run in a pipeline.