Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!newsfeed.xs4all.nl!newsfeed5.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 0.006 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'url:sourceforge': 0.03; 'skip:/ 10': 0.07; 'output,': 0.09; 'file,': 0.15; '[file]...': 0.16; '[option]...': 0.16; 'concatenate': 0.16; 'from:addr:timgolden.me.uk': 0.16; 'from:name:tim golden': 0.16; 'input.': 0.16; 'message-id:@timgolden.me.uk': 0.16; 'received:74.55.86': 0.16; 'received:74.55.86.74': 0.16; 'received:smtp.webfaction.com': 0.16; 'received:webfaction.com': 0.16; 'reversed': 0.16; 'tjg': 0.16; 'windows:': 0.16; 'wrote:': 0.17; 'exists': 0.17; '>>>': 0.18; 'windows': 0.19; 'example': 0.23; 'idea': 0.24; 'linux': 0.24; 'command': 0.24; 'header:In- Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; '---': 0.26; 'first.': 0.27; 'file': 0.32; 'could': 0.32; 'print': 0.32; 'point,': 0.33; 'received:192.168.100': 0.33; 'to:addr:python- list': 0.33; '(1)': 0.34; 'thanks': 0.34; 'but': 0.36; 'subject: (': 0.36; 'data': 0.37; 'subject:: ': 0.38; 'files': 0.38; 'sure': 0.38; 'description': 0.39; 'to:addr:python.org': 0.39; 'received:192': 0.39; 'received:192.168': 0.40; 'subject:-': 0.40; 'skip:u 10': 0.60; 'provide': 0.62; 'details': 0.63; 'more': 0.63; 'reverse': 0.65; 'from:addr:mail': 0.71; 'forced': 0.84; 'subject:Fast': 0.84; 'subject:read': 0.84; 'subject:write': 0.84 Date: Wed, 24 Oct 2012 09:12:16 +0100 From: Tim Golden User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20120907 Thunderbird/15.0.1 MIME-Version: 1.0 To: python-list@python.org Subject: Re: Fast forward-backward (write-read) References: <5086AA35.4000509@it.uu.se> <5086C156.40707@tim.thechases.com> <508793BF.30306@it.uu.se> In-Reply-To: <508793BF.30306@it.uu.se> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit 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: 42 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1351066346 news.xs4all.nl 6906 [2001:888:2000:d::a6]:52571 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:32020 On 24/10/2012 08:07, Virgil Stokes wrote: > On 23-Oct-2012 22:03, Cousin Stanley wrote: >> Virgil Stokes wrote: >> >>> Not sure about "tac" --- could you provide more details on this >>> and/or a simple example of how it could be used for fast reversed >>> "reading" of a data file ? >> tac is available as a command under linux .... >> >> $ whatis tac >> tac (1) - concatenate and print files in reverse >> >> $ whereis tac >> tac: /usr/bin/tac /usr/bin/X11/tac /usr/share/man/man1/tac.1.gz >> >> $ man tac >> >> SYNOPSIS >> tac [OPTION]... [FILE]... >> >> DESCRIPTION >> >> Write each FILE to standard output, last line first. >> >> With no FILE, or when FILE is -, read standard input. >> >> >> I only know that the tac command exists >> but have never used it myself .... >> >> > Unfortunately, I may be forced to process the data on a Windows > platform; but, thanks Cousin for the Linux tip. Well, addressing that specific point, tac is available for Windows: http://unxutils.sourceforge.net/ No idea how efficient it is... TJG