From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: What's the meaning of "^A" in emacs? Date: Wed, 29 Jul 2015 17:35:42 +0200 Message-ID: <874mkn2cz5.fsf@mbork.pl> References: <20150728134848.GA2384@debian> <87k2tkaruw.fsf@nl106-137-147.student.uu.se> <87d1zb9fp3.fsf@yale.edu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1438184179 2155 80.91.229.3 (29 Jul 2015 15:36:19 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Jul 2015 15:36:19 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Jul 29 17:36:11 2015 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZKTOt-0005Vt-9V for geh-help-gnu-emacs@m.gmane.org; Wed, 29 Jul 2015 17:36:11 +0200 Original-Received: from localhost ([::1]:35746 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKTOs-0003DX-Ig for geh-help-gnu-emacs@m.gmane.org; Wed, 29 Jul 2015 11:36:10 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:39683) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKTOh-0003DJ-FI for help-gnu-emacs@gnu.org; Wed, 29 Jul 2015 11:36:00 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZKTOc-0000Jd-MV for help-gnu-emacs@gnu.org; Wed, 29 Jul 2015 11:35:59 -0400 Original-Received: from mail.mojserwer.eu ([2a01:5e00:2:52::8]:41197) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKTOc-0000IU-FJ for help-gnu-emacs@gnu.org; Wed, 29 Jul 2015 11:35:54 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 69D2B8F2003 for ; Wed, 29 Jul 2015 17:35:50 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id R4U2YzlJoVGV for ; Wed, 29 Jul 2015 17:35:48 +0200 (CEST) Original-Received: from localhost (unknown [109.232.24.146]) by mail.mojserwer.eu (Postfix) with ESMTPSA id 3116C8F2002 for ; Wed, 29 Jul 2015 17:35:48 +0200 (CEST) In-reply-to: <87d1zb9fp3.fsf@yale.edu> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a01:5e00:2:52::8 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:106118 Archived-At: On 2015-07-29, at 16:55, Jorge A. Alfaro-Murillo wrote: > Emanuel Berg writes: > >> Navy Cheng writes: >> >>> What't the meaning of "^-characters" such as ^A, ^_, ^O ? I see >>> this characters in some files. And How can I input this >>> characters? Thanks. >> >> When you say "input", do you mean to *insert* them as chars into >> a buffer? If so, just hit C-q first. But I don't think you >> should do this too often (?). > > Yes, why would someone use this? The only thing that I use is the > "form feed" (^L) to divide sections in plain text documents and > then be able to use C-x [ and C-x ] to move between pages. > > Does someone know of any other "control character" use? Contrived, maybe, but legit. In (La)TeX you sometimes need a character you know for sure won't be used anywhere else (at least in a normal document). I know at least one LaTeX package which uses ^A, and I used it myself when implementing a verbatim-like construct as a sort of "escape" (more precisely, a way to insert a LaTeX command in a place where most special characters were not special anymore). Best, -- Marcin Borkowski http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski Faculty of Mathematics and Computer Science Adam Mickiewicz University