Path: csiph.com!usenet.pasdenom.info!dedibox.gegeweb.org!gegeweb.eu!nntpfeed.proxad.net!proxad.net!feeder1-2.proxad.net!usenet-fr.net!nerim.net!novso.com!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!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 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'syntax': 0.04; 'sys': 0.07; 'executed': 0.09; 'parsing': 0.09; 'received:internal': 0.09; 'skip:/ 10': 0.09; 'works.': 0.09; 'message- id:@webmail.messagingengine.com': 0.16; 'received:10.202': 0.16; 'received:10.202.2': 0.16; 'received:66.111': 0.16; 'received:66.111.4': 0.16; 'received:messagingengine.com': 0.16; 'sees': 0.16; 'sudo': 0.16; 'language': 0.16; 'wrote:': 0.18; 'wed,': 0.18; 'trying': 0.19; 'command': 0.22; 'import': 0.22; 'shell': 0.22; 'errors.': 0.24; 'instance,': 0.24; 'passes': 0.24; 'second': 0.26; 'header:In-Reply-To:1': 0.27; 'tim': 0.29; "skip:' 10": 0.31; 'quotes': 0.31; 'handled': 0.32; 'received:66': 0.35; 'case,': 0.35; 'received:10': 0.37; 'nov': 0.38; 'skip:[ 10': 0.38; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'how': 0.40; 'from:no real name:2**0': 0.61; 'simple': 0.61; 'first': 0.61; 'header:Message-Id:1': 0.63; '26,': 0.68; '2014,': 0.84; 'recover': 0.91; 'imagine': 0.93 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=fastmail.us; h= message-id:x-sasl-enc:from:to:mime-version :content-transfer-encoding:content-type:subject:date:in-reply-to :references; s=mesmtp; bh=IL+vaEzzPsZoryOwNqwIqJb0TNs=; b=Z4arQ9 UDcqZzI6Qip+BJlATljF5sAcXwP5Y3XHRUciNLjuXknzjjX52XiBhYRoQlUhp6l3 eK67pbBV0KBUhiK+vdcAgGENGCUassvks7Jw4BlGsrEHWTjKOAF5uzokKBByf+nZ NzDecs7ui4t53fKbx31Q/nr6Bkgd/MzzoxGkA= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=message-id:x-sasl-enc:from:to :mime-version:content-transfer-encoding:content-type:subject :date:in-reply-to:references; s=smtpout; bh=IL+vaEzzPsZoryOwNqwI qJb0TNs=; b=F/Wj5IXZ0nvNtDZyq5jsjxWVgYhstt+jJL6JTH9loiR2Bubi/Z7b wsQwUQoc8kvlMCHwgmwwOMEm+NMUUCHCQFHckpMGYLgkRHgfmqJUxKNsGYYQlUA3 doFo1Ew2tsJFoxUOs8eiD/qXGl+kthKVJfi40Sq2qBDloaYUQqQQSnE= X-Sasl-Enc: f/ZbBnPq+9+mKVuk2mvTIVLFyjaCBYF2beaVWKPdpQNx 1417011145 From: random832@fastmail.us To: python-list@python.org MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain X-Mailer: MessagingEngine.com Webmail Interface - ajax-53201334 Subject: Re: Quotation Ugliness Date: Wed, 26 Nov 2014 09:12:25 -0500 In-Reply-To: <54756D5F.4040806@tundraware.com> References: <54756D5F.4040806@tundraware.com> 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: 37 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1417011148 news.xs4all.nl 2954 [2001:888:2000:d::a6]:40235 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:81567 On Wed, Nov 26, 2014, at 01:04, Tim Daneliuk wrote: > In this case, I am not trying to write a fullblown language or recover > from syntax errors. Here's a usecase - I want to know whether I need > to use a sudo password when the user passes a command on the command line > of a program: > > someprog.py uname && sudo cat /etc/sudoers > > vs. > > someprog.py uname && echo "sudo cat /etc/suoders" > > > In the first instance, I need the sudo passoword, in the second I don't. I think first you need to understand how the command line works. Much of this parsing - including both && and quotes - is handled by the shell before your program ever sees it. Imagine someprog.py is this very simple program: import sys print("%r" % (sys.argv,)) $ someprog.py uname ['someprog.py', 'uname'] $ someprog.py uname && sudo cat /etc/sudoers ['someprog.py', 'uname'] Password: {sudo executed independent of your program} $ someprog.py uname && echo "sudo cat /etc/sudoers" ['someprog.py', 'uname'] sudo cat /etc/sudoers {echo executed independent of your program} $ someprog.py uname "&&" sudo cat /etc/sudoers ['someprog.py', 'uname', '&&', 'sudo', 'cat', '/etc/sudoers'] $ someprog.py uname "&&" echo "sudo cat /etc/sudoers" ['someprog.py', 'uname', '&&', 'echo', 'sudo cat /etc/sudoers'] $ someprog.py 'uname && echo "sudo cat /etc/sudoers"' ['someprog.py', 'uname && echo "sudo cat /etc/sudoers"']