From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Multiple encodings in one file Date: Mon, 29 Apr 2024 22:02:17 -0400 Message-ID: References: <86plu8skew.fsf@gnu.org> <86jzkgq8v0.fsf@gnu.org> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="11878"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:87Oj9UzYggDdkRNJpTI9xgHeMOY= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Apr 30 04:03:01 2024 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1s1cph-0002tO-Lp for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 30 Apr 2024 04:03:01 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1s1cpD-00027f-40; Mon, 29 Apr 2024 22:02:31 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s1cpB-00027V-8Y for help-gnu-emacs@gnu.org; Mon, 29 Apr 2024 22:02:29 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s1cp9-0007CH-QP for help-gnu-emacs@gnu.org; Mon, 29 Apr 2024 22:02:29 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1s1cp6-0001wi-Hk for help-gnu-emacs@gnu.org; Tue, 30 Apr 2024 04:02:24 +0200 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.248, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:146505 Archived-At: >> Thank you for the time. What you said gives me some hope but I have >> a follow-up question. If I visit a file literally, make a change, and >> save it, the file seems to be different only where I changed it. Is >> that true? > > If you save it while binding coding-system-to-write to no-conversion, > yes. IOW, you need to disable encoding while saving. Also, if you open the file as a if it was all utf-8, then the utf-8 parts of the file should look just fine (and the MARC-8 parts may look screwy) and if you edit it and save the result it *should* result in a valid file where only the part your changed was modified. >> If so, then does the following seem reasonable. >> >> 1 Find a file literally. >> 2 The user will accept that some characters will show octal codes or >> something similar. >> 3 Edit the records where understandable and possible. >> 4 Save file. For a quick&dirty solution that should work as long as you're doing limited changes and only in parts that are mostly ASCII. If you're designing a major mode, maybe a better approach would look like: read the file literally (i.e. as bytes) and treat it as a kind of directory or archive (think tar-mode, dired, archive-mode, Rmail) so only show a summary of the contents, then let the users "open" a record which is then extracted (and decoded) into another buffer. Stefan