Xref: utzoo comp.lang.c:36241 comp.unix.programmer:1108
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.lang.c,comp.unix.programmer
Subject: Re: Catching termination of child process and system() call
Message-ID: <15239@smoke.brl.mil>
Date: 19 Feb 91 01:49:48 GMT
References: <1356@geovision.UUCP> <9882@dog.ee.lbl.gov> <2608@root44.co.uk>
Followup-To: comp.lang.c
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 14

In article <2608@root44.co.uk> gwc@root.co.uk (Geoff Clare) writes:
>POSIX does not specify the precise encoding of information in the status
>returned by wait(), system(), etc., so portable programs should not
>rely on the traditional encoding Chris describes above.  Instead macros
>are provided in <sys/wait.h> to extract the relevant data from the status:

(1)  PORTABLE programs MUST follow Chris's recommendation; not all
existing UNIX environments provide the macros to which you alluded.
PORTABLE != POSIX

(2)  Does POSIX really neglect to specify the bits?  Certainly as of
the trial-use 1003.1 standard the bits were specified.  In any case,
all UNIX systems must continue to act as Chris decided, regardless of
whether POSIX requires additional facilities for this.