From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Max Nikulin Newsgroups: gmane.emacs.devel Subject: Re: How to get DISPLAY of emacsclient? Date: Mon, 28 Nov 2022 22:33:22 +0700 Message-ID: References: <973588ef-d931-47a0-66d3-f8d70d92bd57@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="12954"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Nov 28 17:51:59 2022 Return-path: Envelope-to: ged-emacs-devel@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 1ozhMN-0003CR-EA for ged-emacs-devel@m.gmane-mx.org; Mon, 28 Nov 2022 17:51:59 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ozhLk-0004X8-VQ; Mon, 28 Nov 2022 11:51:21 -0500 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 1ozg8U-0004a4-5a for emacs-devel@gnu.org; Mon, 28 Nov 2022 10:33:34 -0500 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 1ozg8S-0001zH-OO for emacs-devel@gnu.org; Mon, 28 Nov 2022 10:33:33 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1ozg8O-0000u5-6S for emacs-devel@gnu.org; Mon, 28 Nov 2022 16:33:28 +0100 X-Injected-Via-Gmane: http://gmane.org/ Content-Language: en-US In-Reply-To: <973588ef-d931-47a0-66d3-f8d70d92bd57@gmail.com> Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: 23 X-Spam_score: 2.3 X-Spam_bar: ++ X-Spam_report: (2.3 / 5.0 requ) BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FORGED_GMAIL_RCVD=1, FORGED_MUA_MOZILLA=2.309, FREEMAIL_FORGED_FROMDOMAIN=0.001, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, NICE_REPLY_A=-0.257, NML_ADSP_CUSTOM_MED=0.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Mon, 28 Nov 2022 11:51:03 -0500 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:300674 Archived-At: On 28/11/2022 03:36, Jim Porter wrote: > > Looking through the emacsclient.c code, I think this is intentional, and > if you want to do something like this, the above workaround is exactly > what you're supposed to do: > >      If the -c option is used (without -t) and no --display argument >      is provided, try $DISPLAY. >      Without the -c option, we used to set 'display' to $DISPLAY by >      default, but this changed the default behavior and is sometimes >      inconvenient.  So we force users to use "--display $DISPLAY" if >      they want Emacs to connect to their current display. Thank you, I have reread emacsclinet code and have realized that I did not expect such behavior. At first I missed that environment is sent to server only if -c option is specified and the DISPLAY environment may be ignored. I believed that display value is always received, but can not be obtained because it is assigned to a local variable. Actually it is not sent for simple eval. It is not stressed in the manual that emacsclient uses the --display option and the DISPLAY environment in a rather unusual way in comparison to other X application. I considered --display option as a way to override $DISPLAY and nothing more. emacsclient --display "$DISPLAY" --eval ... behaves as required despite it looks a bit strange. It reuses existing X connection or creates a new hidden frame. As a result X selection becomes available without additional function calls. On 28/11/2022 08:19, Po Lu wrote: > `x-open-connection' is your friend. The problem was to determine DISPLAY argument for this function. Moreover it is not enough and (gui-get-selection) return nil if just `x-open-connection' is called from emacsclient. In this sense `server-select-display' is better, but it requires DISPLAY as well. On 27/11/2022 23:12, Gregory Heytings wrote: > there is no display involved. If you create an emacsclient process with > -c or -r, then in Elisp you can get the display on which the frame is > displayed with (getenv "DISPLAY"), or (cdr (assq 'display > (frame-parameters))). I was seeking a way to avoid creation a visible frame and to call a function that does not work without X connection. So I should thank Jim again for drawing my attention why the effect of the --display option is stronger than for the DISPLAY environment. This option indirectly solves the problem.