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Date: Thu, 8 Jul 2004 19:13:35 +0200 (W. Europe Daylight Time)
From: Daniel Lungu <lungu AT nagra DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: negative error status: gcc vs. cl
In-Reply-To: <Pine.WNT.4.21.0407081106020.247-100000@pc0197.nagra-kudelski.ch>
Message-ID: <Pine.WNT.4.21.0407081839590.215-100000@pc0197.hq.k.grp>
X-X-Sender: lungu AT castor DOT hq DOT k DOT grp
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:) "The value of status may be 0, EXIT_SUCCESS, EXIT_FAILURE, [CX] or any
:) other value"

:) but what you shouldn't do is expect the exit status in the shell to be
:) anything other than the least-significant byte of the value you passed:

:) "though only the least significant 8 bits (that is, status & 0377) shall
:) be available to a waiting parent process."

It is exactly what happens when compiling nerr.c with gcc:

-----unsigned-8b-exit-status-----
% nerr-gcc.exe; echo $?
254

sizeof (int) = 4 [B] on i686

:) So -2 comes back as 254.  Sounds like perfectly correct 2's complement
:) arithmetic to me!

Indeed, but same arithmetic should apply when exit status comes from a "cl
compiled .exe". It is not the case when compiling nerr.c with cl:

-----wrong-nil(!)-exit-status-----
% nerr-cl.exe; echo $?
0

$? cannot distinguish exit(0) from exit(-2) ... this is logical anarchy! One
cannot reliably test exit status of legacy windoze binaries.

:)    cheers, 
:)      DaveK

ksh :) yields the same Cygwin bug. Thanks for answers. Daniel.


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