Path: csiph.com!usenet.pasdenom.info!news.albasani.net!feeder.erje.net!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <vs@it.uu.se>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.055
X-Spam-Evidence: '*H*': 0.89; '*S*': 0.00; 'skip:/ 10': 0.07; 'output,': 0.09; 'file,': 0.15; '[file]...': 0.16; '[option]...': 0.16; 'concatenate': 0.16; 'input.': 0.16; 'reversed': 0.16; 'wrote:': 0.17; 'exists': 0.17; 'windows': 0.19; 'to:name:python- list@python.org': 0.20; 'example': 0.23; 'linux': 0.24; 'command': 0.24; 'header:In-Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; '---': 0.26; 'charset:iso-8859-15': 0.26; 'first.': 0.27; 'file': 0.32; 'could': 0.32; 'print': 0.32; '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; 'forced': 0.84; 'subject:Fast': 0.84; 'subject:read': 0.84; 'subject:write': 0.84
X-SENDER-IP: [213.112.50.224]
X-LISTENER: [smtp.bredband.net]
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AjsmAE+Th1DVcDLgPGdsb2JhbAANN4pOt0YBAQEBOIJSAQEBAQM4UQsYCSUPAjIGAQ0GDQgBAa9Lk0WLYIZrA6kd
X-IronPort-AV: E=Sophos;i="4.80,639,1344204000"; d="scan'208";a="138660881"
Date: Wed, 24 Oct 2012 09:07:43 +0200
From: Virgil Stokes <vs@it.uu.se>
User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:17.0) Gecko/17.0 Thunderbird/17.0
MIME-Version: 1.0
To: "python-list@python.org" <python-list@python.org>
Subject: Re: Fast forward-backward (write-read)
References: <5086AA35.4000509@it.uu.se> <5086C156.40707@tim.thechases.com> <mailman.2677.1351012669.27098.python-list@python.org> <k66t6q$819$1@dont-email.me>
In-Reply-To: <k66t6q$819$1@dont-email.me>
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
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 <python-list.python.org>
List-Unsubscribe: <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.2738.1351064070.27098.python-list@python.org>
Lines: 34
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1351064070 news.xs4all.nl 6912 [2001:888:2000:d::a6]:37127
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:32015

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.