Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.018 X-Spam-Evidence: '*H*': 0.96; '*S*': 0.00; 'true,': 0.05; 'python3': 0.07; '22,': 0.09; 'pretend': 0.09; 'technician': 0.09; 'python': 0.11; 'jan': 0.12; '(it': 0.16; 'command.': 0.16; 'confuse': 0.16; 'have).': 0.16; 'maliciously': 0.16; 'module?': 0.16; 'protecting': 0.16; 'received:10.215': 0.16; 'script,': 0.16; 'status?': 0.16; 'wrote:': 0.18; 'thu,': 0.19; 'import': 0.22; 'saying': 0.22; 'header:User-Agent:1': 0.23; "shouldn't": 0.24; 'decide': 0.24; 'server.': 0.24; 'header:In-Reply-To:1': 0.27; 'tried': 0.27; 'wondering': 0.29; 'chris': 0.29; 'direction': 0.30; 'skip:( 20': 0.30; "i'm": 0.30; 'that.': 0.31; '>>>>': 0.31; 'anyone': 0.31; 'linux': 0.33; 'running': 0.33; 'skip:s 30': 0.35; 'test': 0.35; 'but': 0.35; 'false': 0.36; 'subject:?': 0.36; 'list': 0.37; 'received:10': 0.37; 'clear': 0.37; 'server': 0.38; 'jason': 0.38; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'expect': 0.39; "couldn't": 0.39; 'itself': 0.39; 'use.': 0.39; 'to:addr:python.org': 0.39; 'how': 0.40; 'even': 0.60; 'ago,': 0.61; 'more': 0.64; 'charset:windows-1252': 0.65; 'worth': 0.66; '(probably': 0.84; '2014,': 0.84; '2015': 0.84; 'bailey': 0.84; 'dhcp': 0.84; 'hassle': 0.84; 'beneficial': 0.91; 'subject:Check': 0.95 Date: Fri, 23 Jan 2015 09:02:32 -0700 From: Jason Bailey User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Subject: Re: Check for running DHCP daemon? References: <54C030E9.8010404@emerytelcom.com> <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com> In-Reply-To: Content-Type: multipart/alternative; boundary="------------030508010204010408050702" X-Originating-IP: [10.215.90.84] X-ClientProxiedBy: ETEXCH2.corp.emerytelcom.com (10.30.90.61) To ETEXCH2.corp.emerytelcom.com (10.30.90.61) X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 149 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1422028991 news.xs4all.nl 2862 [2001:888:2000:d::a6]:58052 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:84350 --------------030508010204010408050702 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Hmm, okay. What you are saying makes sense. I'm actually wondering if it might be more beneficial for me to check if the local DHCP port (udp 67) is bound and in use. I had tried to do this some time ago, and couldn't get it working right (it would always test true, even when it shouldn't have). Can anyone steer me in the right direction on port status? Jason Bailey Network Technician Emery Telcom Office: (435) 636-0052 JBailey@emerytelcom.com On 01/21/2015 09:39 PM, Chris Angelico wrote: > On Thu, Jan 22, 2015 at 2:58 PM, Jason Bailey wrote: >> How would I get a list of running processes with the subprocess module? The >> documentation wasn't clear to me. > Using the ps command. :) > > rosuav@dewey:~$ python3 > Python 3.4.2 (default, Oct 8 2014, 10:45:20) > [GCC 4.9.1] on linux > Type "help", "copyright", "credits" or "license" for more information. >>>> import subprocess >>>> b" dhcpd\n" in subprocess.check_output(["ps","-A"]) > False > > rosuav@sikorsky:~$ python3 > Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07) > [GCC 4.7.2] on linux > Type "help", "copyright", "credits" or "license" for more information. >>>> import subprocess >>>> b" dhcpd\n" in subprocess.check_output(["ps","-A"]) > True > > There's a DHCP server running on Sikorsky, but not on Dewey. :) > > Of course, this can be faked. Any process can call itself 'dhcpd' and > pretend to be the DHCP server. It's up to you to decide how to deal > with that. (Probably by not caring, I would expect. Unless you > actually expect someone to maliciously try to confuse your script, > it's not worth the hassle of protecting yourself.) > > ChrisA --------------030508010204010408050702 Content-Type: text/html; charset="windows-1252" Content-Transfer-Encoding: 7bit
Hmm, okay. What you are saying makes sense.

I'm actually wondering if it might be more beneficial for me to check if the local DHCP port (udp 67) is bound and in use. I had tried to do this some time ago, and couldn't get it working right (it would always test true, even when it shouldn't have). Can anyone steer me in the right direction on port status?

Jason Bailey
Network Technician
Emery Telcom
Office: (435) 636-0052

On 01/21/2015 09:39 PM, Chris Angelico wrote:
On Thu, Jan 22, 2015 at 2:58 PM, Jason Bailey <JBailey@emerytelcom.com> wrote:

How would I get a list of running processes with the subprocess module? The
documentation wasn't clear to me.

Using the ps command. :)

rosuav@dewey:~$ python3
Python 3.4.2 (default, Oct  8 2014, 10:45:20)
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.

import subprocess
b" dhcpd\n" in subprocess.check_output(["ps","-A"])

False

rosuav@sikorsky:~$ python3
Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.

import subprocess
b" dhcpd\n" in subprocess.check_output(["ps","-A"])

True

There's a DHCP server running on Sikorsky, but not on Dewey. :)

Of course, this can be faked. Any process can call itself 'dhcpd' and
pretend to be the DHCP server. It's up to you to decide how to deal
with that. (Probably by not caring, I would expect. Unless you
actually expect someone to maliciously try to confuse your script,
it's not worth the hassle of protecting yourself.)

ChrisA

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