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Message-ID: <52D6B9DC.50903@coverity.com>
Date: Wed, 15 Jan 2014 11:39:56 -0500
From: Tom Honermann <thonermann AT coverity DOT com>
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To: <cygwin AT cygwin DOT com>
Subject: Re: fork() + file descriptor bug in 1.7.27(0.271/5/3) 2013-12-09 11:54
References: <831845 DOT 98759 DOT bm AT smtp116 DOT sbc DOT mail DOT ne1 DOT yahoo DOT com>
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On 01/13/2014 11:06 AM, tednolan AT bellsouth DOT net wrote:
...
> 		switch (fork()) {
> 			
> 			/* error */
> 			case -1:
...
> 			/* child */
> 			case 0:
> 				fprintf(stderr, "child\n"); fflush(stderr);
> 				exit(0);
> 				break;

The above code is incorrect.  It is always wrong to call exit() from a 
forked process that has not yet called one of the exec() family of 
functions.  _exit() should be called instead.  Best case, calling exit() 
will result in double flushing of any stream buffers held by the parent 
at the time fork() is called (since the buffers will (eventually) be 
flushed by the parent as well as the child (unless at least one of the 
processes aborts or exits with _exit()).

Tom.

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