From: ara.t.howard@...
Date: 2006-10-10T13:21:21+09:00
Subject: useful at_exit idiom


i'm constantly struggling with the fact that children need to use exit! to
prevent exit handlers registered in the parent being called twice, for example:


   harp:~ > cat a.rb
   at_exit{ puts 'parent' }

   fork{
     at_exit{ puts 'child' }
   } and Process.wait


   harp:~ > ruby a.rb
   child
   parent
   parent


arggh.  this is a neat work-around:


   harp:~ > cat a.rb
   at_exit{ puts 'parent' }

   fork{
     at_exit{ exit! }
     at_exit{ puts 'child' }
   } and Process.wait


   harp:~ > ruby a.rb
   child
   parent


i'm sure i'm not the first one to think of this, but it sure is handy to
separate the parent's handlers from the child's...  anyone see issues with
this?

-a
-- 
my religion is very simple.  my religion is kindness. -- the dalai lama