From owner-freebsd-current@FreeBSD.ORG Wed Jul 18 20:09:55 2007 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9A10016A402 for ; Wed, 18 Jul 2007 20:09:55 +0000 (UTC) (envelope-from rpaulo@fnop.net) Received: from core.fnop.net (mx.fnop.net [82.102.11.82]) by mx1.freebsd.org (Postfix) with ESMTP id 2DD0713C48D for ; Wed, 18 Jul 2007 20:09:55 +0000 (UTC) (envelope-from rpaulo@fnop.net) Received: from core.fnop.net (mx.fnop.net [82.102.11.82]) by core.fnop.net (Postfix) with ESMTP id B30A9690D8E; Wed, 18 Jul 2007 21:03:57 +0100 (WEST) Received: by core.fnop.net (Postfix, from userid 1015) id 4DA91690E1A; Wed, 18 Jul 2007 21:03:57 +0100 (WEST) X-Spam-Checker-Version: SpamAssassin 3.1.7 (2006-10-05) on core.fnop.net X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00, FORGED_RCVD_HELO autolearn=ham version=3.1.7 Received: from epsilon.local (62.169.111.86.rev.optimus.pt [62.169.111.86]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by core.fnop.net (Postfix) with ESMTP id 2C3FD690D8E; Wed, 18 Jul 2007 21:03:55 +0100 (WEST) Message-ID: <469E737B.5090609@fnop.net> Date: Wed, 18 Jul 2007 21:09:31 +0100 From: Rui Paulo User-Agent: Thunderbird 2.0.0.4 (X11/20070704) MIME-Version: 1.0 To: Fred Gilham References: <469D651C.6080504@fnop.net> <40882.1184765616@snapdragon.csl.sri.com> In-Reply-To: <40882.1184765616@snapdragon.csl.sri.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV using ClamSMTP Cc: current@freebsd.org Subject: Re: less -r broken with long lines X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Jul 2007 20:09:55 -0000 Fred Gilham wrote: > Rui Paulo wrote: > >> Hi, >> There's something about how the new less version handles lines greater >> than the virtual terminal's size. >> >> Test case on an xterm/rxvt/screen session: >> >> less -r /etc/syslog.conf - you won't see the $FreeBSD$ id tag because >> of the long line regarding to /var/log/messages. Try resizing your >> terminal so that this line fits in the right number of columns. You'll >> see the problem disappear. >> >> less -r /etc/rc.firewall - since there are no long lines in the first >> page, you won't notice the problem >> >> Everything works fine if less is used without the -r argument or if less >> is run from the console. >> >> Does this ring any bell to anyone? >> >> Regards. >> -- >> Rui Paulo > > This is documented behavior. From the "less" manpage: > > -r or --raw-control-chars > Causes "raw" control characters to be displayed. The default is > to display control characters using the caret notation; for > example, a control-A (octal 001) is displayed as "^A". Warning: > when the -r option is used, less cannot keep track of the actual > appearance of the screen (since this depends on how the screen > responds to each type of control character). Thus, various dis- > play problems may result, such as long lines being split in the > wrong place. It depends on the interpretation. "various display problems may result" may very well be a reference to the fact that control characters mangle the output. I wasn't expecting long lines to mangle the output. If you less -r a file without control characters, but with a least a line wider than your screen size, you'll notice the problem. But, either way, less has been doing this for ages. I just took a long time to notice it. Regards. -- Rui Paulo