Catching termination of child process and system() call

[Doug Gwyn]

In article <2608 at root44.co.uk> gwc at 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.