[Tutor] Re: timer vs. timeout - struct.unpack

[Kent Johnson]

Ah, you are importing socket with
   from socket import *
so the except line should be just
   except error, (errno, strerror):

What version of Python are you using? Python 2.3 has a settimeout() method 
on a socket and timeouts raise socket.timeout instead of socket.error. I 
have used this successfully with TCP sockets to time out an HTTP connection.

Kent

At 09:29 PM 8/9/2004 +0800, S Bobb wrote:
>Thanks for the help.
>
>I've placed the try/except just as you suggested. Now it's coming back with
>another error:
>
>Traceback (most recent call last):
>  File "ipinstalludpclient3.py", line 50, in ?
>    except socket.error, (errno, strerror):
>AttributeError: type object '_socketobject' has no attribute 'error'
>
>The script is still running through properly, it just isn't exiting without
>an exception.
>
>I've figured out another roundabout way to extract the MAC address now, so
>that I don't have to use dnet.
>Does anyone have any other suggestions for creating a UUID? I just read that
>commands is Unix-centric. I'd like to be able to use this script
>cross-platform.
>
>Sean
>
>
>
>
>>From: Kent Johnson <kent_johnson at skillsoft.com>
>>To: "goluptious" <goluptious at hotmail.com>,tutor at python.org
>>Subject: Re: [Tutor] Re: timer vs. timeout - struct.unpack
>>Date: Mon, 09 Aug 2004 08:29:30 -0400
>>
>>Sean Bobb,
>>
>>It looks like maybe the socket module is throwing an exception when the 
>>socket read times out. You can use a try / except block to catch the 
>>exception and close the socket. For example, something like this:
>>
>>sock = ... # set up socket
>>try:
>>   while 1:
>>     messin = sock.recv(236)
>>     # handle data from socket
>>except socket.error, (errno, strerror):
>>   sock.close()
>>   if errno != 11:
>>     raise  # unexpected error, don't hide it
>>
>>You may have to tweak this a bit, I am guessing at what is going on.
>>
>>Kent
>>
>>At 06:31 PM 8/9/2004 +0800, goluptious wrote:
>>>I figured out how to extract the data and and display it, but I still
>>>haven't managed to figure out a proper method to run my loop.
>>>Is there some way to use the Traceback to close the loop so that I can close
>>>the socket?
>>>Is a timer a better option? If so, should I use the threading timer or
>>>create my own using time?
>>>
>>>BTW, after a little more searching I found out that the commId was actually
>>>a UUID, so I modified the script to incorporate this also.
>>>
>>>If anyone has some advice as to how to do all these functions a little less
>>>crudely, or perhaps something that I will be able to port to other operating
>>>systems I would really appreciate it. (I've tried just copying over the
>>>dnet.so file from my Linux box to Windows, but it returns an error no module
>>>named dnet, I guess libdnet has to be compiled under Windows.)
>>>
>>>Thank you,
>>>
>>>Sean Bobb
>>>
>>>
>>>###--->BEGIN SCRIPT ---###
>>>#! /usr/bin/env python
>>>
>>>from socket import *
>>>from struct import *
>>>import re
>>>import dnet
>>>import commands
>>>
>>>def uuidgen():
>>>     return commands.getoutput('uuidgen')
>>>
>>>servid = '96c363be-b894-43b5-8501-ae5c00e779b3'
>>>resv = '\x00'
>>>commId = uuidgen()
>>>packSize = '\xec\x00'
>>>macAddr = '\xff\xff\xff\xff\xff\xff'
>>>ipAddr = ''
>>>netMask =''
>>>gateWay = ''
>>>Dns1 = ''
>>>Dns2 = ''
>>>Dns3 = ''
>>>httpPort =''
>>>messout = servid + (4 * resv) + commId + (4 * resv) + packSize + (2 * resv)
>>>+ macAddr + (146 * resv)
>>>rcvtime = pack('ll', 1l, 0l)
>>>
>>>sock = socket(AF_INET, SOCK_DGRAM)
>>>sock.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)
>>>sock.setsockopt(SOL_SOCKET, SO_RCVTIMEO, rcvtime)
>>>sock.bind(('<broadcast>',58798))
>>>sock.sendto(messout, ('<broadcast>', 58797))
>>>while 1:
>>>  messin = sock.recv(236)
>>>  messunpack = unpack('236s', messin)
>>>  spl = re.split('96c36.*?\\xec\\x00\\x00\\x02', messunpack[0])
>>>  spl1 = spl[1]
>>>  macaddr = dnet.eth_ntoa(spl1[0:6])
>>>  ipaddr = inet_ntoa(spl1[8:12])
>>>  netmask = inet_ntoa(spl1[12:16])
>>>  gateway = inet_ntoa(spl1[16:20])
>>>  dns1 = inet_ntoa(spl1[20:24])
>>>  dns2 = inet_ntoa(spl1[24:28])
>>>  dns3 = inet_ntoa(spl1[28:32])
>>>  httpport = str(ord(spl1[32]) * 256 + ord(spl1[33]))
>>>  print "MAC Address: " + macaddr + "\nIP Address: " + ipaddr + 
>>> "\nNetmask: "
>>>+ netmask + "\nGateway: " + gateway +  "\nDNS1: " + dns1 + "\nDNS2: " + dns2
>>>+ "\nDNS3: " + dns3 + "\nHTTP Port: " + httpport + "\n\n"
>>>sock.close()
>>>_______________________________________________
>>>Tutor maillist  -  Tutor at python.org
>>>http://mail.python.org/mailman/listinfo/tutor
>
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