From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Spencer Baugh Newsgroups: gmane.emacs.bugs Subject: bug#62958: [PATCH] Set PAGER=cat in comint.el Date: Tue, 09 May 2023 12:30:42 -0400 Message-ID: References: <83edof6oln.fsf@gnu.org> <83zg724kea.fsf@gnu.org> <835y97jnfd.fsf@gnu.org> <83pm7aay70.fsf@gnu.org> <874jol1rml.fsf@catern.com> <831qjpbj8j.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7347"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: sbaugh@catern.com, 62958@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue May 09 18:31:17 2023 Return-path: Envelope-to: geb-bug-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 1pwQFB-0001im-73 for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 09 May 2023 18:31:17 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pwQF2-0004Da-Aa; Tue, 09 May 2023 12:31:08 -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 1pwQEx-0004DG-A8 for bug-gnu-emacs@gnu.org; Tue, 09 May 2023 12:31:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pwQEx-00078H-1b for bug-gnu-emacs@gnu.org; Tue, 09 May 2023 12:31:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pwQEw-0006ba-Hc for bug-gnu-emacs@gnu.org; Tue, 09 May 2023 12:31:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Spencer Baugh Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 09 May 2023 16:31:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 62958 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 62958-submit@debbugs.gnu.org id=B62958.168364985125369 (code B ref 62958); Tue, 09 May 2023 16:31:02 +0000 Original-Received: (at 62958) by debbugs.gnu.org; 9 May 2023 16:30:51 +0000 Original-Received: from localhost ([127.0.0.1]:44270 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pwQEk-0006b6-G2 for submit@debbugs.gnu.org; Tue, 09 May 2023 12:30:50 -0400 Original-Received: from mxout5.mail.janestreet.com ([64.215.233.18]:57623) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pwQEi-0006ar-EA for 62958@debbugs.gnu.org; Tue, 09 May 2023 12:30:48 -0400 In-Reply-To: <831qjpbj8j.fsf@gnu.org> (Eli Zaretskii's message of "Tue, 09 May 2023 18:46:36 +0300") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:261427 Archived-At: Eli Zaretskii writes: >> From: sbaugh@catern.com >> Date: Tue, 09 May 2023 14:55:31 +0000 (UTC) >> Cc: Spencer Baugh , 62958@debbugs.gnu.org >> >> Eli Zaretskii writes: >> >> >> From: Spencer Baugh >> >> Cc: 62958@debbugs.gnu.org >> >> Date: Mon, 08 May 2023 15:38:12 -0400 >> >> >> >> > Pagination is not needed, and gets in the way, when the output of >> >> > the program is directed to an Emacs buffer, so in those cases >> >> > pagination should be disabled. To disable pagination, this >> >> > variable's value should be a string that names a program, such >> >> > as \"cat\", which passes through all of the output without any >> >> > filtering or delays. Comint will then set the PAGER variable >> >> > to name that program, when it invokes external programs." >> >> >> >> I think it's worth noting the fact that there are programs which depend >> >> on pagination for their normal functionality. How about this short >> >> additional paragraph added after your text: >> >> >> >> "Disabling pagination means programs will produce their entire output >> >> immediately. If only part of the output is useful, this can be >> >> wasteful. For some programs, this can be avoided by using commands (for >> >> example, `vc-print-log') which run the program, limit the output it >> >> produces, and let the user interactively browse the output inside >> >> Emacs." >> > >> > Sorry, I don't understand: why would it matter that a program produces >> > its output immediately when that output is redirected to an Emacs >> > buffer? Whatever the amount of output, the user can always page >> > through it interactively and conveniently using the normal movement >> > commands, no? What am I missing? >> >> If the command produces a lot of output it can take a long time to run >> and slow down Emacs. >> >> For example, if a user disables pagination, runs M-x shell, and then >> runs "git log" in the Emacs repo, it takes ~3.5 minutes to run and >> produces ~1.5 million lines. Even if all they want is to see the 10 >> most recent commits. There are several negative effects of this, in >> decreasing order of importance: >> >> - The shell buffer now has way more output, which slows down navigation >> and operations on that buffer forever after, including font lock. >> - The user's shell is blocked during that whole time, preventing further >> shell commands. >> - git log producing unnecessary output wastes CPU and IO. >> >> If "git log" is run with a pager, it can complete as soon as the user >> exits the pager, and it only produces a few lines. > > But this is impossible in general, AFAIU: most comint clients aren't > prepared for interactive paging anyway. If someone wants paging, they > should use "M-x term" or "M-x ansi-term", the terminal emulators that > Emacs provides. Yes. I of course know that, that's why I filed this bug :) Nevertheless, today by default many programs run in comint clients will run a pager, and even though it is a hassle and gets in the way inside Emacs, it does prevent some programs from producing lots of output and yielding the negative effects I mentioned previously: >> - The shell buffer now has way more output, which slows down navigation >> and operations on that buffer forever after, including font lock. >> - The user's shell is blocked during that whole time, preventing further >> shell commands. >> - git log producing unnecessary output wastes CPU and IO. Because of these negative effects which will start happening for some programs when the user disables pagination, I think it's important for users to know that there's alternatives for such programs: namely, using native Emacs interfaces like vc-print-log.