From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Luc Teirlinck Newsgroups: gmane.emacs.devel Subject: Re: S-backspace Date: Wed, 28 May 2003 20:46:11 -0500 (CDT) Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: <200305290146.h4T1kBV18272@eel.dms.auburn.edu> References: <20030527141845.GA13165@gnu.org> NNTP-Posting-Host: main.gmane.org X-Trace: main.gmane.org 1054172764 32151 80.91.224.249 (29 May 2003 01:46:04 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Thu, 29 May 2003 01:46:04 +0000 (UTC) Cc: miles@gnu.org Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Thu May 29 03:46:01 2003 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 19LCUT-0008MD-00 for ; Thu, 29 May 2003 03:46:01 +0200 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian)) id 19LCiu-0006DQ-00 for ; Thu, 29 May 2003 04:00:57 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.20) id 19LCWD-0001p6-W6 for emacs-devel@quimby.gnus.org; Wed, 28 May 2003 21:47:50 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.20) id 19LCVZ-0001NN-HY for emacs-devel@gnu.org; Wed, 28 May 2003 21:47:09 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.20) id 19LCV9-0000lO-67 for emacs-devel@gnu.org; Wed, 28 May 2003 21:46:43 -0400 Original-Received: from manatee.dms.auburn.edu ([131.204.53.104]) by monty-python.gnu.org with esmtp (Exim 4.20) id 19LCUa-0000AS-62; Wed, 28 May 2003 21:46:08 -0400 Original-Received: from eel.dms.auburn.edu (eel.dms.auburn.edu [131.204.53.108]) h4T1k7oc002010; Wed, 28 May 2003 20:46:07 -0500 (CDT) Original-Received: (from teirllm@localhost) by eel.dms.auburn.edu (8.11.6+Sun/8.11.6) id h4T1kBV18272; Wed, 28 May 2003 20:46:11 -0500 (CDT) X-Authentication-Warning: eel.dms.auburn.edu: teirllm set sender to teirllm@dms.auburn.edu using -f Original-To: rms@gnu.org In-reply-to: (message from Richard Stallman on Wed, 28 May 2003 19:57:42 -0400) Original-cc: rv@gnu.org Original-cc: emacs-devel@gnu.org Original-cc: alex@gnu.org X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Emacs development discussions. List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:14403 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:14403 Richard Stallman wrote: Caution! Danger! Do not necessarily try! `C-M-' Kill balanced expression backward (`backward-kill-sexp'). Perhaps we should delete that binding. The hard thing is that it works fine when you are not in X. The binding itself is clearly not dangerous, once Emacs even gets to see the binding the danger is over. The danger consists in encouraging people to use it without properly warning them. I suggested adding such a warning to the relevant section of the Emacs manual. There are four closely related bindings involved: C-M-, C-Alt-, C-M- and C-Alt-. Strictly speaking, as Stefan remarked, the one that kills the X server is C-Alt-, but many keyboards do not have separate Alt and Meta keys, making the last two key-combinations very dangerous. Adding a shift key to these last two ones is no help: the X server gets killed anyway. The two first ones are used for logout on many operating systems. All those I know of warn (actually even present several options), leading to inconvenience and confusion rather than outright danger. Moreover, here shifting does seem to work. (This may not work for all operating systems. It is sufficient if it works for operating systems using X. Otherwise, one can use C-M-backspace.) On my system, C-M- is controlled by sawfish, which binds it to "gnome logout". In my .emacs I bind C-M-S- to `backward-kill-sexp', sawfish ignores it because of the shift key, and everything seems to work fine. It does not work under emacs -nw, but plenty of bindings do not seem to work under emacs -nw. So what about the following solution: 1. Explain the dangers in the relevant section of the Emacs manual. 2. Add C-M-S- as a binding for backward-kill-sexp. Sincerely, Luc.