Path: csiph.com!usenet.pasdenom.info!news.etla.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed3.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 0.121 X-Spam-Level: * X-Spam-Evidence: '*H*': 0.76; '*S*': 0.00; 'subject:text': 0.05; 'subject:file': 0.07; 'unified': 0.09; 'subject:How': 0.10; 'times,': 0.14; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'wrote:': 0.18; 'print': 0.22; 'possibly': 0.26; 'header:In-Reply-To:1': 0.27; 'tried': 0.27; 'waste': 0.30; 'message-id:@mail.gmail.com': 0.30; 'easier': 0.31; 'bunch': 0.31; 'view.': 0.31; 'with,': 0.31; 'file': 0.32; 'text': 0.33; 'updated': 0.34; 'there,': 0.34; 'could': 0.34; 'display': 0.35; 'something': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'edge': 0.36; 'monitored': 0.36; 'to:addr:python-list': 0.38; 'files': 0.38; 'pm,': 0.38; 'rather': 0.38; 'little': 0.38; 'to:addr:python.org': 0.39; 'logs': 0.60; 'ago,': 0.61; 'simply': 0.61; 'first': 0.61; 'save': 0.62; 'happen': 0.63; 'yourself': 0.78; 'etc,': 0.84; "it'd": 0.84; 'subject:read': 0.84; 'trouble.': 0.91; '2013': 0.98 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=A0N1m+vfQRqKnnN8i1vgT9UN43NK14uHylDhwCrq9JY=; b=dprZAbsl9/8vZ/Ayjwqt5QgZvowf9CeI6CyB3tuq4FHjtf4Nu/yaRwfU1FCmCFyHGn bV7dda/BBO9bxvI4oyOUTObTev2ZV00LP6Cp7cyudkYiuyz+eKH4yRw3QaFy4/oJ+mU+ IrpS/MJ1Mr/eHcKiaX90d0GPIf5Q9ph9uySGDNTfkiAiDqgnMW+n6cYcPsm6eCf2dJES laBf2ytAz92mB9ILTl2p4g3XG7XUAaU3amaXBmycARimDBcU01q4NexG/RrBbn3D22AJ wbYvl1TnKoObvDlz8rRnovASV+IE2MTlC1rYuq2Hz5VHuPnmSD4/ixntAux7dZw2DBk4 ddhw== MIME-Version: 1.0 X-Received: by 10.66.182.36 with SMTP id eb4mr1120678pac.125.1381030082406; Sat, 05 Oct 2013 20:28:02 -0700 (PDT) In-Reply-To: References: <04ee91f9-1cbf-4364-bca3-da25aa4db45f@googlegroups.com> Date: Sun, 6 Oct 2013 14:28:02 +1100 Subject: Re: How to streamingly read text file and display whenever updated text From: Chris Angelico To: python-list@python.org Content-Type: text/plain; charset=ISO-8859-1 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: 17 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1381031863 news.xs4all.nl 15920 [2001:888:2000:d::a6]:49270 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:56234 On Sun, Oct 6, 2013 at 2:17 PM, wrote: > After tried many times, updated text file is not shown, it only print text at the first time. The implementation of tail has a lot of little oddities to deal with edge cases. Why not simply use it? A while ago, I wanted to make a system that would tail a bunch of logs on a bunch of computers, and display it all to me in a single unified view. Rather than write something that opened a whole lot of files and monitored them, I simply forked a 'tail' process for each file and reacted to its stdout. It was way WAY easier than dealing with everything that could possibly happen (log rotation, etc, etc, etc) - not that it'd be impossible to deal with, but it's a waste of time reinventing this particular wheel. Build on top of what's already there, save yourself the trouble. ChrisA