Python recv loop

Ihsan Junaidi Ibrahim ihsan at
Mon Feb 11 01:48:24 CET 2013


I'm implementing a python client connecting to a C-backend server and am currently stuck to as to how to proceed with receiving variable-length byte stream coming in from the server.

I have coded the first 4 bytes (in hexadecimal) of message coming in from the server to specify the length of the message payload i.e. 0xad{...}

I've managed to receive and translate the message length until I reach my second recv which I readjusted the buffer size to include the new message length.

However that failed and recv received 0 bytes. I implemented the same algorithm on the server side using C and it work so appreciate if you can help me on this.

# receive message length
    print 'receiving data'
    mlen = sock.recv(4)
        nbuf = int(mlen, 16)
    except ValueError as e:
        print 'invalid length type'
        return -1

    while True:
        buf = sock.recv(nbuf)

        if not buf:

    slen = len(buf)
    str = "{0} bytes received: {1}".format(slen, buf)
    print str

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