thanks for "down" answers
Dave Jones
djones at megatest.UUCP
Thu Dec 15 06:46:17 AEST 1988
>From article <1886 at loral.UUCP>, by jlh at loral.UUCP (Physically Phffft):
...
> In all his examples he used wait ( (char *) 0).
> I pointed out to him that wait wanted an address in which to
> stuff a result, and using 0 was probably not a good idea. His
> reply was 'thats how it is in my manual', after a few minutes
> of discussion it got upgraded to 'I tried it on my system and it
> works'.
Both perfectly valid and correct responces.
>From the manual:
#include <sys/wait.h>
pid = wait(status)
int pid;
union wait *status;
pid = wait(0)
int pid;
[Your instructor correctly casts the 0 to a pointer-type, which
the manual omits.]
If you want the status, you pass a non-null pointer and wait
knows what to do. If you don't want the status, you pass a
null pointer, and wait knows what *not* to do.
To paraphrase Samuel L. Clemmons, I think that you will discover
in couple of years that your instructors have learned quite a bit
in the interim. :-)
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