From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#37564: [PATCH] don't export LINES and COLUMNS env vars in term to fix ncurses applications Date: Tue, 01 Oct 2019 21:58:25 +0300 Message-ID: <83y2y48f8u.fsf@gnu.org> References: <87y2y5lfnb.fsf@1e0.co.uk> <83eezxatsv.fsf@gnu.org> <87tv8slb6w.fsf@mattleach.net> <83a7aka1q5.fsf@gnu.org> <87sgocfh8c.fsf@mattleach.net> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="151256"; mail-complaints-to="usenet@blaine.gmane.org" Cc: 37564@debbugs.gnu.org To: Matthew Leach Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Oct 01 20:59:13 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iFNMf-000dGv-D7 for geb-bug-gnu-emacs@m.gmane.org; Tue, 01 Oct 2019 20:59:13 +0200 Original-Received: from localhost ([::1]:46756 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iFNMc-0003Tr-Vw for geb-bug-gnu-emacs@m.gmane.org; Tue, 01 Oct 2019 14:59:11 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:44385) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iFNMW-0003TW-Pc for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 14:59:05 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iFNMV-0005bF-MU for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 14:59:04 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:54181) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iFNMV-0005b2-JU for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 14:59:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iFNMV-00031C-HK for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 14:59:03 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 01 Oct 2019 18:59:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 37564 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 37564-submit@debbugs.gnu.org id=B37564.156995633711590 (code B ref 37564); Tue, 01 Oct 2019 18:59:02 +0000 Original-Received: (at 37564) by debbugs.gnu.org; 1 Oct 2019 18:58:57 +0000 Original-Received: from localhost ([127.0.0.1]:34769 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iFNMO-00030s-La for submit@debbugs.gnu.org; Tue, 01 Oct 2019 14:58:56 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:35301) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iFNML-00030c-Ni for 37564@debbugs.gnu.org; Tue, 01 Oct 2019 14:58:55 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:38984) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iFNMG-0005Tk-9H; Tue, 01 Oct 2019 14:58:48 -0400 Original-Received: from [176.228.60.248] (port=3833 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iFNMD-0004ng-0M; Tue, 01 Oct 2019 14:58:47 -0400 In-reply-to: <87sgocfh8c.fsf@mattleach.net> (message from Matthew Leach on Tue, 01 Oct 2019 19:33:39 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 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.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:168072 Archived-At: > From: Matthew Leach > Cc: 37564@debbugs.gnu.org > Date: Tue, 01 Oct 2019 19:33:39 +0100 > > >> I'm curious as to which programs you are referring? AFAIK, if a program > >> tries to read the LINES and COLUMNS environment variables, using > >> `getenv()', they don't exist. > > > > What makes you say that? > > If I run the C program in my previous post in an xterm and resize I get: > > getenv: (null) (null) > ioctl: 24 80 > getenv: (null) (null) > ioctl: 42 169 > > You can see that doing getenv() on LINES and COLUMNS returns a null > pointer. I've tested this same behaviour on gnome-terminal and numerous > other terminal emulators. I simply tried "env | fgrep LINES" and I do see the variable, although it wasn't there before I launched Emacs. 'env' is just another program accessing the environment, right? I have no idea why your test program doesn't see that, but then I'm far from being an expert on these issues. > > Emacs exports these variables into the environment that is passed to > > child subprocesses, so those subprocesses will definitely see them > > using getenv. > > I'm no expert on how these things work but it doesn't appear to be the > way that it's done, on my machine anyway. Perhaps there are programs > that uses these variables on MacOS or Windows? I tried the above on a Trisquel GNU/Windows machine, FWIW. > I'm testing this on the latest Emacs Git version. I can see that > window-adjust-process-window-size-function is used in term.el however, > this doesn't appear to update the environment variables exported to the > terminal process. AFAIR, it's supposed to send the corresponding ioctl command, in addition to setting LINES and COLUMNS. > If I run the same program with term on Emacs git and > resize I get: > > getenv: 31 80 > ioctl: 30 89 > getenv: 31 80 > ioctl: 30 90 > getenv: 31 80 > ioctl: 30 91 > getenv: 31 80 > ioctl: 31 92 > getenv: 31 80 > ioctl: 31 93 > getenv: 31 80 > ioctl: 31 94 > ... > > Notice that the values returned by getenv don't change. Again, the "env | fgrep LINES" method does show the change when I resize the window on the machine I tried this, so I'm unsure why you don't see it. > Given that this functionality is broken, I'm suggesting that we don't > export the variables. I don't agree that it's broken; it isn't for me. I think someone who understands more than I do about this stuff should chime in and explain why we see such different results.