argv[] terminated by a NULL pointer?

[The Grey Wolf]

In article <14603 at dog.ee.lbl.gov>, torek at elf.ee.lbl.com (Chris Torek) wrote:
 * In article <12187 at hub.ucsb.edu> angst at cs.ucsb.edu
 * [argv terminated by null?]
 *
 * Under Version 6 Unix, argv[argc] is (char *)-1.  This violates the
 * following wording from X3.159-1989 (`ANSI C'):
 * 
 *     argv[argc] shall be a null pointer.  (2.1.1.2, p. 7)
 * 
 * Thus, the answer to your question is both `no' and `yes'.

"Never go to the Elves for counsel,
 for they will tell you both yes and no..."  -- J.R.R. Tolkien

You're sure holding true to form, Chris :-) ...

Anyone got any clues why they started using NULL pointers instead of
(char *) -1?  Is there any system which will actually consider (char *) -1
a valid (virtual) memory location?  Or, rather, WERE there any machines
which would do so (were: most machines now are word-aligned).

 * -- 
 * In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 415 486 5427)
 * Berkeley, CA		Domain:	torek at ee.lbl.gov


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