Why isn't argv[argc]==(char *)0 ?

[Doug Gwyn]

In article <1391 at skye.ed.ac.uk> richard at aiai.UUCP (Richard Tobin) writes:
>So it's probably the first version that had it.  From the Sixth Edition
>man page for exec(II):

C as delivered with Sixth Edition UNIX is unusable anyway by today's
standards.  Long, long ago I upgraded the C system on the Sixth Edition
UNIX installation that I was responsible for, and many others did the
same.  One of the things that we fixed was the use everywhere of -1 as
an "invalid pointer" indicator; that is untenable in modern C.

(Yes, I know about sbrk() and SIG_ERR.)