Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!bcstec!ruben
From: ruben@bcstec.boeing.com (Reuben Wachtfogel)
Newsgroups: comp.unix.questions
Subject: Re: How can a child detect the death of its parent
Summary: Maybe ...
Message-ID: <931@bcstec.boeing.com>
Date: 7 Jun 91 20:01:58 GMT
References: <298@wimpy.nms.gdc.portal.com>
Organization: Boeing Computer Services, Seattle
Lines: 30

In article <298@wimpy.nms.gdc.portal.com>, bergquis@nms.gdc.portal.com (Brett Bergquist) writes:
> I have an application with forks a tightly coupled child process to handle
> communications functions.  The child communicates to the parent through
> a pipe.
> 
> I know how to detect the death of the child process using SIGCLD in the parent,
> but how can I detect the death of the parent process in the child?
> 

The parent could be set up to signal the child upon most non-violent
terminations with kill (e.g. use signal to trap termination faults)

Additionally the child could poll for the existence of the parent.
signal(SIGALRM, check_for_parent);
alarm(TEN_SECONDS);

where check_for_parent checks for getppid()==1
which means that the parent is gone and the child has
been adopted by the init (UID=1) process. 

I doubt this is very robust though, especially in cases where the
parent has zombied out, and I'll be checking here for a better answer.

----------------------------------------------------------------------
I have used something like this on APOLLO and it seems to work but
...

P.S. My recent posting containing site-specific article numbers
	 was intended to inspire people to REALLY read the FAQs. Thanx
	 to the many (!!) letters noting my goof. Please no more.