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Date: Tue, 22 Jul 2003 17:53:46 -0400
From: Steve Coleman <steve DOT coleman AT jhuapl DOT edu>
Subject: Re: subprocess i/o interaction with shell (bash&cmd): shells compete
 for input with user program!
In-reply-to: <ulluqmh01.fsf@gnu.org>
To: sds AT gnu DOT org
Cc: cygwin AT cygwin DOT com
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References: <uadb68wgz DOT fsf AT gnu DOT org> <20030722145702 DOT GA17342 AT redhat DOT com>
 <uvftu7cp5 DOT fsf AT gnu DOT org> <20030722172316 DOT GC17916 AT redhat DOT com>
 <ulluqmh01 DOT fsf AT gnu DOT org>

Sam Steingold wrote:

>I am not using fork().
>just plain exec().
>  
>
If thats the case then the exec() you are linking is not behaving as a 
POSIX exec() call, because if it did you would not still have two 
processes to even compete for the I/O streams. The first process image 
would be "replaced" by the second.

% man execl

8< ---------
"The  exec family of functions replaces the current process image with a 
new process
 image."
-------------

So, either you are not using Cygwin execl(), or it is VERY broken, which 
I doubt because too many applications have been working correctly for 
too long for the second to be the case.





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