From owner-freebsd-questions@FreeBSD.ORG  Sat Nov 22 06:49:31 2003
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 9E5A216A4CE
	for <freebsd-questions@freebsd.org>;
	Sat, 22 Nov 2003 06:49:31 -0800 (PST)
Received: from clunix.cl.msu.edu (clunix.cl.msu.edu [35.9.2.10])
	by mx1.FreeBSD.org (Postfix) with ESMTP id B74BC43FDF
	for <freebsd-questions@freebsd.org>;
	Sat, 22 Nov 2003 06:49:29 -0800 (PST)
	(envelope-from jerrymc@clunix.cl.msu.edu)
Received: (from jerrymc@localhost)
	by clunix.cl.msu.edu (8.11.7p1+Sun/8.11.7) id hAMEnNT24343;
	Sat, 22 Nov 2003 09:49:23 -0500 (EST)
From: Jerry McAllister <jerrymc@clunix.cl.msu.edu>
Message-Id: <200311221449.hAMEnNT24343@clunix.cl.msu.edu>
To: weiwuzhang@hotmail.com (Zhang Weiwu)
Date: Sat, 22 Nov 2003 09:49:23 -0500 (EST)
In-Reply-To: <3FBF5DEA.2030405@hotmail.com> from "Zhang Weiwu" at Nov 22, 2003
	09:00:26 PM
X-Mailer: ELM [version 2.5 PL2]
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
cc: freebsd-questions@freebsd.org
Subject: Re: newbie: use <CR> in RE?
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 22 Nov 2003 14:49:31 -0000

> 
> Hello. Just want to know how to use special character in Regular Expression.
> 
> I wish to remove all the carrier returns from a text file, I can use:
> tr -d "\r" < text_file > modified_text_file
> But if I do:
> sed -i s/\r//g text_file
> it actually removes all the character "r" from the file.
> 
> This is also a problem in vi(1). Besides <CR> I wish to manipulate 
> tabstops and line-feeds with RE too.

So why not just use tr?      \t should get tabs, as you noted \r gets CRs
I don't know linefeed off hand, but wouldn't be surprised if it was \l.
It follows the usual conventions.

There are more things besides -d that you can do with tr also.

////jerry
>