thanks for "down" answers

[Guy Harris]

 >It gets worse.  2-3 weeks ago one of my instructors decided to explain
 >fork, exec, and waits.  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'.  So, Chris, Doug, and Henry, prepare yourself
 >for 30 or so bright and eager new programmers who will think
 >'wait ((char *) 0)' is the preferred way to do things.

No, if you're not interested in the return status of the process for
which you're waiting, and you're running on a UNIX system more recent
than, say, V6, the preferred way of doing this is

	wait((int *)0)

not

	wait((char *)0)

If the manual says "char *", it's wrong.  (Yes, I know about BSD's
"union wait"; it was a dumb idea, and the BSD *kernel* still thinks it's
supposed to be a pointer to "int".)

Passing a NULL pointer is *not* an error; "wait" treats that as an
indication that it is not to return the exit status.  Aside from the
incorrect data type, your instructor was correct.