Description

   The wait function suspends the parent process until the final
   status of a terminated child is returned from the child.

   On OpenVMS Version 7.0 and higher systems, the wait function is
   equivalent to waitpid( 0, status, 0 ) if you include <wait.h> and
   compile with the _POSIX_EXIT feature-test macro set (either with
   /DEFINE=_POSIX_EXIT or with #define _POSIX_EXIT at the top of
   your file, before any file inclusions).