Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.questions
Subject: Re: How to get Status of processes in C environment
Message-ID: <4049@auspex.auspex.com>
Date: 11 Sep 90 18:32:10 GMT
References: <25467.26e7ac6a@kuhub.cc.ukans.edu> <1990Sep8.221008.3145@ecn.purdue.edu>
Organization: Auspex Systems, Santa Clara
Lines: 13

>Try wait(2). Note the arg to the sys call is different on a BSD and SysV.

Actually, from the kernel's standpoint, the argument is the *same* in
BSD and other systems.  Some excessively-helpful person at Berkeley
created "union wait" as a *user-mode* wrapper around the "int" that the
underlying implementation of "wait()", in most if not all UNIX systems,
returns.

If you just ignore "union wait" (and the "lint" complaints that doing so
will give you), and treat the "status" argument to "wait()" as an "int
*", even on BSD systems, your code will still work (unless the
implementor of your UNIX system screwed up badly), but will be more
portable and won't be polluted with #ifdefs.