GNU bug report logs - #11432
Application that sets LINES/COLUMNS env vars behaves weird in term and ansi-term

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 11432 in the body.
You can then email your comments to 11432 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Nikos Chantziaras <realnc <at> gmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: Application that sets LINES/COLUMNS env vars behaves weird in term
	and ansi-term
Date: Tue, 08 May 2012 16:56:03 +0300

I have a curses application (written in C++) that during start-up does:

  static char linesEnv[32];
  static char columnsEnv[32];
  /* Init the above vars */
  putenv(linesEnv);
  putenv(columnsEnv);

linesEnv and columnsEnv contain "LINES=N" and "COLUMNS=N" respectively, 
with N being the current terminal dimensions.

Now this sounds like a totally useless thing to do; why would you set 
these env vars if they're already set.  This is done in order to work 
around a bug in an old Solaris version.  But on other systems, this 
should have no effect.

But with emacs it does have an effect; the application's output is all 
messed up.  Characters appear in wrong places or entirely missing and 
everything is pretty much messed up.  I modified the program to not 
export the env vars when TERM=eterm (or eterm-color).  But in case this 
is a bug in Emacs, I'm reporting it here.

I'm using GNU Emacs 23.4.2 built without X support, with Ncurses 5.9 on 
Gentoo AMD64.  The problem also appears in Emacs 23.1 with X support on 
Ubuntu 10.04 (which is the system of the user who reported the problem 
to me.)

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.