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From: thomas@uplog.se (Thomas Tornblom)
Newsgroups: comp.unix.questions
Subject: Re: Can a parent process determine its child's status ?
Message-ID: <THOMAS.90Feb22124443@uplog.uplog.se>
Date: 22 Feb 90 11:44:43 GMT
References: <5090.25e135aa@mva.cs.liv.ac.uk>
Sender: thomas@uplog.se (Thomas Tornblom)
Organization: TeleLOGIC Uppsala AB
Lines: 39
In-Reply-To: adh@mva.cs.liv.ac.uk's message of 20 Feb 90 12:18:50 GMT

In article <5090.25e135aa@mva.cs.liv.ac.uk> adh@mva.cs.liv.ac.uk writes:

   Does anyone know how a parent process can determine the status of one
   of its children if it *hasn't* executed a wait ? It could arrange to 
   catch a SIGCLD signal, but if the parent had several children it
   wouldn't know which one had sent it the SIGCLD ... would it ?


Yes it would.
Arrange to catch SIGCLD and do a wait in the catcher:

main()
{
	.
	.
	signal(SIGCLD, reaper);
	.
	.
}

reaper()
{
	int pid;
	int status;

	pid = wait(&status);

	/* pid is now the pid of the child that has died/changed status */

	signal(SIGCLD, reaper);		/* have to re-initialize in sysV */
}

Hope this helps.
Thomas
-- 
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