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X-HELO:	endymion.arp.harvard.edu
To:	cygwin AT cygwin DOT com
From:	Norton Allen <allen AT huarp DOT harvard DOT edu>
Subject:	Cygwin parenting issue
Message-ID:	<7cb7cef9-0e4b-8e9d-0c14-ffe3e9e79a13@huarp.harvard.edu>
Date:	Wed, 1 Jan 2020 16:01:00 -0500
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I have a project that involves starting a number of programs in the 
background and then monitoring and reporting when they terminate. My 
approach has been to write a small application called 'parent' that 
loops on waitpid() until there are no more children. I invoke it in a 
script like:

#! /bin/bash
program1 &
program2 &
program3 &
exec parent

This of course works under Linux, but under Cygwin, although 'ps' 
documents the parent/child relationship, waitpid() immediately returns 
ECHILD, indicating there are no child processes. If I use the shell's 
waitpid, that works alright, so I am wondering whether the problem is a 
casualty of the exec.

I have a minimal test setup at 
https://github.com/nthallen/test_parenting, along with examples showing 
how it works under Linux and Cygwin.

Is this something that we would expect to work under Cygwin?

-Norton


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