Newsgroups: comp.windows.x
Path: utzoo!sq!lee
From: lee@sq.sq.com (Liam R. E. Quin)
Subject: xterm bug in parsing -S option
Message-ID: <1990Aug22.210424.18890@sq.sq.com>
Organization: SoftQuad Inc.
Date: Wed, 22 Aug 90 21:04:24 GMT
Lines: 52

X11 R4 xterm has a -S option that takes the last two characters of a
terminal name ("p3" for /dev/ttyp3, for example) and the number of
a file descriptor, so you can do
	xterm -Sp312
to read from file descriptor 12 on /dev/ttyp3.

It works unless the file descriptor is zero, in which case the test in
the code seems to be incorrect.

Here is a (totally unofficial and not tested) patch.  I don't seem to
be able to recompile xterm without remaking all of the libraries, or
spending hours hacking the makefile to use -lX11 instead of ../../lib/X/X11
and so on, sorry.

In any case it seems better to test the return value of sscanf() in the
following code.

Lee

Directory: /usr/src/x/mit/clients/xterm

*** main.c.orig	Wed Aug 22 16:09:47 1990
--- main.c	Wed Aug 22 16:13:11 1990
***************
*** 722,730 ****
  #endif	/* TIOCCONS */
  		continue;
  	     case 'S':
! 		sscanf(*argv + 2, "%c%c%d", passedPty, passedPty+1,
! 		 &am_slave);
! 		if (am_slave <= 0) Syntax(*argv);
  		continue;
  #ifdef DEBUG
  	     case 'D':
--- 722,731 ----
  #endif	/* TIOCCONS */
  		continue;
  	     case 'S':
! 		if (sscanf(*argv + 2, "%c%c%d", passedPty, passedPty+1,
! 			 &am_slave) != 3) {
! 		    Syntax(*argv);
! 		}
  		continue;
  #ifdef DEBUG
  	     case 'D':


-- 
Liam R. E. Quin,  lee@sq.com, {utai,utzoo}!sq!lee,  SoftQuad Inc., Toronto
Nicholas: [...]  The best/ Thing we can do is to make wherever we're lost in
Look as much like home as we can. [Christopher Fry, The Lady's Not For Burning]